On May 24, 9:25*pm, "
wrote:
On May 24, 12:47*pm, harry wrote:









On May 24, 3:42*pm, "
wrote:

On May 24, 1:04*am, harry wrote:

On May 23, 6:12*pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46*am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). *I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. *We'll probably only use the pool on the weekends. *Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? *Is my thinking skewed? *Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event.
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that..
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall.
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 *;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single *phase/
100A.

I'm sorry for you harry. *If true, just another sign of the
inadequacy of the Britts.

**There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? *The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. *What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. *200A are very
common too. *A friend has 300A. *All those are done
using single phase, nothing unusual at all.

A 15Kw three phase system here is just 22 A/phase as the voltage is
410v.
Putting loads like this on a single phase system causes voltages to
appear on the neutral which can upset RCD devices.- Hide quoted text -

- Show quoted text -

Only if the single phase system is half-assed. *Apparently
that must be the case. *And all this time I thought you Britts
were so superior. *Most houses only have a 100A service and
if you need more you have to go to 3 phase. *Must be a grand
place. *Or, more likely, your're just BSing as usual.

A 100A supply is 23Kw. here. Why would you need more than that?

On Fri, 24 May 2013 23:17:08 -0700 (PDT), harry
wrote:

On May 24, 9:25*pm, "
wrote:
On May 24, 12:47*pm, harry wrote:









On May 24, 3:42*pm, "
wrote:

On May 24, 1:04*am, harry wrote:

On May 23, 6:12*pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46*am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). *I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. *We'll probably only use the pool on the weekends. *Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? *Is my thinking skewed? *Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event.
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that.
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall.
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 *;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single *phase/
100A.

I'm sorry for you harry. *If true, just another sign of the
inadequacy of the Britts.

**There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? *The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. *What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. *200A are very
common too. *A friend has 300A. *All those are done
using single phase, nothing unusual at all.

A 15Kw three phase system here is just 22 A/phase as the voltage is
410v.
Putting loads like this on a single phase system causes voltages to
appear on the neutral which can upset RCD devices.- Hide quoted text -

- Show quoted text -

Only if the single phase system is half-assed. *Apparently
that must be the case. *And all this time I thought you Britts
were so superior. *Most houses only have a 100A service and
if you need more you have to go to 3 phase. *Must be a grand
place. *Or, more likely, your're just BSing as usual.

A 100A supply is 23Kw. here. Why would you need more than that?

Oh, things like electric ovens, air conditioners (or heat pumps),
electric water heaters, clothes dryers. Any number of things that
makes life comfortable, which you Brits obviously haven't heard of.

Like I said in another post, I have two 150s (72kW). In my other
house it's only a single 200A (48kW) entrance.

On Fri, 24 May 2013 23:15:35 -0700 (PDT), harry
wrote:

On May 24, 9:22*pm, "
wrote:
On May 24, 1:13*pm, harry wrote:









On May 24, 3:42*pm, "
wrote:

On May 24, 1:04*am, harry wrote:

On May 23, 6:12*pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46*am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). *I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. *We'll probably only use the pool on the weekends. *Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? *Is my thinking skewed? *Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event.
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that.
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall.
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 *;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single *phase/
100A.

I'm sorry for you harry. *If true, just another sign of the
inadequacy of the Britts.

**There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? *The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. *What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. *200A are very
common too. *A friend has 300A. *All those are done
using single phase, nothing unusual at all.

Electric heating of swimming pools is virtually unheard of due to
cost, there is a gas supply to 99% of places.

It's not really electric heating. *That terms is typically used
to refer to resistance heating. *The pools use heat pumps,
which are referred to as heat pumps. *If gas is the only
viable option in the UK, how do you explain this:

http://www.dreamheatpumps.co.uk/

http://www.ebay.co.uk/itm/350793470032

http://www.lighthousepools.co.uk/

Like I said, if they let you out of the nuthouse at
least once in a while, maybe you'd see some stuff.

Virtually never used.

Sure, who should we believe? *You who doesn't even have
any experience with a pool or all the companies obviously
selling heat pump based heaters?

Most homes here have wet heating systems. This boiler can easily be
used to heat the pool via a heat exchanger.

What most do doesn't mean there isn't a viable market for heat
pump systems. *Most pools here in the US don't have
heat pump systems either. *Matters not a wit. *If the
application is right, they can be the right choice.



Where there is no gas, either oil or propane is used.
Heat pumps are being offered in the last ten years or so but there are
icing problems on the evaporators in our climate.

Icing on a pool heat pump? *Icing indeed!

Due to the climate, outdoor pools are unusual here, Of the few that
exist a tiny percentage are heated.
Indoor pools are obviously vastly more expensive and these too are
rare.
How many outdoor pools are there in Alaska?

Doesn't the evaporator in you freezer ice up you dolt?
Why therefore shouldn't the evaporator in any heat pump ice up?

Perhaps because the evaporator doesn't get cold enough? You do know
that outdoor pools are used during the summer? Speaking of dolt!

On May 25, 10:14*am, wrote:
On Fri, 24 May 2013 23:15:35 -0700 (PDT), harry





wrote:
On May 24, 9:22 pm, "
wrote:
On May 24, 1:13 pm, harry wrote:

On May 24, 3:42 pm, "
wrote:

On May 24, 1:04 am, harry wrote:

On May 23, 6:12 pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46 am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. We'll probably only use the pool on the weekends. Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? Is my thinking skewed? Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event..
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated.. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that.
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall.
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 ;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single phase/
100A.

I'm sorry for you harry. If true, just another sign of the
inadequacy of the Britts.

There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. 200A are very
common too. A friend has 300A. All those are done
using single phase, nothing unusual at all.

Electric heating of swimming pools is virtually unheard of due to
cost, there is a gas supply to 99% of places.

It's not really electric heating. That terms is typically used
to refer to resistance heating. The pools use heat pumps,
which are referred to as heat pumps. If gas is the only
viable option in the UK, how do you explain this:

http://www.dreamheatpumps.co.uk/

http://www.ebay.co.uk/itm/350793470032

http://www.lighthousepools.co.uk/

Like I said, if they let you out of the nuthouse at
least once in a while, maybe you'd see some stuff.

Virtually never used.

Sure, who should we believe? You who doesn't even have
any experience with a pool or all the companies obviously
selling heat pump based heaters?

Most homes here have wet heating systems. This boiler can easily be
used to heat the pool via a heat exchanger.

What most do doesn't mean there isn't a viable market for heat
pump systems. Most pools here in the US don't have
heat pump systems either. Matters not a wit. If the
application is right, they can be the right choice.

Where there is no gas, either oil or propane is used.
Heat pumps are being offered in the last ten years or so but there are
icing problems on the evaporators in our climate.

Icing on a pool heat pump? Icing indeed!

Due to the climate, outdoor pools are unusual here, Of the few that
exist a tiny percentage are heated.
Indoor pools are obviously vastly more expensive and these too are
rare.
How many outdoor pools are there in Alaska?

Doesn't the evaporator in you freezer ice up you dolt?
Why therefore shouldn't the evaporator in any heat pump ice up?

Perhaps because the evaporator doesn't get cold enough? You do know
that outdoor pools are used during the summer? *Speaking of dolt! *- Hide quoted text -


Yeah, an evaporator on a pool heat pump freezing
up is about as dumb as dumb gets. You have to
love the strawman about Alaska. The OP is talking
about using a heat pump for a pool in Florida and
harry turns it into Alaska. Good grief! No one claimed
a heat pump was a viable solution for Alaska.

On May 25, 2:11*am, wrote:
On Fri, 24 May 2013 19:04:55 -0700 (PDT), "





wrote:
On May 24, 4:13*pm, Oren wrote:
On Fri, 24 May 2013 15:41:26 -0400, wrote:
On Fri, 24 May 2013 12:38:56 -0700, chaniarts
wrote:

On 5/24/2013 12:22 PM, Oren wrote:
On Fri, 24 May 2013 10:29:58 -0700, chaniarts
wrote:

No, there is no insulation between the pool and the ground. *It doesn't get that cold down here for that kind of thing, I would think.

you'd be wrong. ground temp is always less than air temp, unless you're
living on a volcano. so, it's always a heat sink 24x7. insulation around
a pool is always a winner, but it's hard to put in after the pool is done.

I worked in pool construction as a teen, In Florida, no less. Not once
was insulation involved in the construction of the in ground pools..

The *cement gunite is ~ 8 inches thick, full of steel rebar and
retains heat for some time.

cost.

yes it retains heat. but the earth is a pretty large heat sink, and
it'll win every time. otherwise ground loops for heating/cooling
exchangers wouldn't be an economic win.

i would bet that every pool north of 5 degrees of latitude would benefit
from insulation, most especially heated ones. no one wants to pay for
that up front.

Heating pools is fairly insignificant in Florida.

I'd go so far as to say the water table is warm. (seasonable)- Hide quoted text -

- Show quoted text -

Well, it certainly is more than 32F, but it is still below what you
would want far a swimming pool for at least 6 months every year. * No
matter what, there is going to be a lot of heat loss into the ground,
and the ground is very wet/conductive in FL. *You need to study the
air loss from the surface and the conducted loss thru the walls and
bottom of the pool to see where your emphasis should be, *It is
conceivable that you should drain the pool, put insulation all around
the sides of the pool and then refill the pool.

Huh?
How do you get the insulation behind the concrete?

That would seem to be a good question

For that matter, if you have a liner based pool, I'm
not sure you could do much with that either. Not sure
what you have behind the liner, ie if there is room for
some kind of insulation, like expanded foam maybe?

A good question is why they don't insulate new pools?
If planned for as part of the construction there could be
room for sufficient insulation. And while it would add to
the cost, you would think the payback would be pretty
reasonable, assuming you do some amount of pool
heating.

On Sat, 25 May 2013 07:35:48 -0700 (PDT), "
wrote:

On May 25, 2:11*am, wrote:
On Fri, 24 May 2013 19:04:55 -0700 (PDT), "





wrote:
On May 24, 4:13*pm, Oren wrote:
On Fri, 24 May 2013 15:41:26 -0400, wrote:
On Fri, 24 May 2013 12:38:56 -0700, chaniarts
wrote:

On 5/24/2013 12:22 PM, Oren wrote:
On Fri, 24 May 2013 10:29:58 -0700, chaniarts
wrote:

No, there is no insulation between the pool and the ground. *It doesn't get that cold down here for that kind of thing, I would think.

you'd be wrong. ground temp is always less than air temp, unless you're
living on a volcano. so, it's always a heat sink 24x7. insulation around
a pool is always a winner, but it's hard to put in after the pool is done.

I worked in pool construction as a teen, In Florida, no less. Not once
was insulation involved in the construction of the in ground pools.

The *cement gunite is ~ 8 inches thick, full of steel rebar and
retains heat for some time.

cost.

yes it retains heat. but the earth is a pretty large heat sink, and
it'll win every time. otherwise ground loops for heating/cooling
exchangers wouldn't be an economic win.

i would bet that every pool north of 5 degrees of latitude would benefit
from insulation, most especially heated ones. no one wants to pay for
that up front.

Heating pools is fairly insignificant in Florida.

I'd go so far as to say the water table is warm. (seasonable)- Hide quoted text -

- Show quoted text -

Well, it certainly is more than 32F, but it is still below what you
would want far a swimming pool for at least 6 months every year. * No
matter what, there is going to be a lot of heat loss into the ground,
and the ground is very wet/conductive in FL. *You need to study the
air loss from the surface and the conducted loss thru the walls and
bottom of the pool to see where your emphasis should be, *It is
conceivable that you should drain the pool, put insulation all around
the sides of the pool and then refill the pool.

Huh?
How do you get the insulation behind the concrete?

That would seem to be a good question

For that matter, if you have a liner based pool, I'm
not sure you could do much with that either. Not sure
what you have behind the liner, ie if there is room for
some kind of insulation, like expanded foam maybe?

A good question is why they don't insulate new pools?
If planned for as part of the construction there could be
room for sufficient insulation. And while it would add to
the cost, you would think the payback would be pretty
reasonable, assuming you do some amount of pool
heating.



I can't come up with a single idea as to what the insulation would be.

It would have to:

- support the weight of a concrete pool or crack the pool

- last for ages under ground

- how would the water table impact the material

Now, on a casino roof top pool, it would seem there would be an easy
way.

On May 25, 11:49*am, Oren wrote:
On Sat, 25 May 2013 07:35:48 -0700 (PDT), "





wrote:
On May 25, 2:11 am, wrote:
On Fri, 24 May 2013 19:04:55 -0700 (PDT), "

wrote:
On May 24, 4:13 pm, Oren wrote:
On Fri, 24 May 2013 15:41:26 -0400, wrote:
On Fri, 24 May 2013 12:38:56 -0700, chaniarts
wrote:

On 5/24/2013 12:22 PM, Oren wrote:
On Fri, 24 May 2013 10:29:58 -0700, chaniarts
wrote:

No, there is no insulation between the pool and the ground. It doesn't get that cold down here for that kind of thing, I would think.

you'd be wrong. ground temp is always less than air temp, unless you're
living on a volcano. so, it's always a heat sink 24x7. insulation around
a pool is always a winner, but it's hard to put in after the pool is done.

I worked in pool construction as a teen, In Florida, no less. Not once
was insulation involved in the construction of the in ground pools.

The cement gunite is ~ 8 inches thick, full of steel rebar and
retains heat for some time.

cost.

yes it retains heat. but the earth is a pretty large heat sink, and
it'll win every time. otherwise ground loops for heating/cooling
exchangers wouldn't be an economic win.

i would bet that every pool north of 5 degrees of latitude would benefit
from insulation, most especially heated ones. no one wants to pay for
that up front.

Heating pools is fairly insignificant in Florida.

I'd go so far as to say the water table is warm. (seasonable)- Hide quoted text -

- Show quoted text -

Well, it certainly is more than 32F, but it is still below what you
would want far a swimming pool for at least 6 months every year. No
matter what, there is going to be a lot of heat loss into the ground,
and the ground is very wet/conductive in FL. You need to study the
air loss from the surface and the conducted loss thru the walls and
bottom of the pool to see where your emphasis should be, It is
conceivable that you should drain the pool, put insulation all around
the sides of the pool and then refill the pool.

Huh?
How do you get the insulation behind the concrete?

That would seem to be a good question

For that matter, if you have a liner based pool, I'm
not sure you could do much with that either. Not sure
what you have behind the liner, ie if there is room for
some kind of insulation, like expanded foam maybe?

A good question is why they don't insulate new pools?
If planned for as part of the construction there could be
room for sufficient insulation. *And while it would add to
the cost, you would think the payback would be pretty
reasonable, assuming you do some amount of pool
heating.

I can't come up with a single idea as to what the insulation would be.

It would have to:

- support the weight of a concrete pool or crack the pool

- last for ages under ground

- how would the water table impact the material

Now, on a casino roof top pool, it would seem there would be an easy
way.- Hide quoted text -

- Show quoted text -

I agree there are some issues. But then insulation is used
with concrete pours for basements that are going to
be heated. Not all the time, but I've seen it done on TV,
like This Old House, etc. Google ICF concrete.

On May 24, 11:17*pm, harry wrote:
On May 24, 9:25*pm, "
wrote:









On May 24, 12:47*pm, harry wrote:

On May 24, 3:42*pm, "
wrote:

On May 24, 1:04*am, harry wrote:

On May 23, 6:12*pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46*am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). *I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. *We'll probably only use the pool on the weekends. *Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? *Is my thinking skewed? *Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event.
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that.
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall..
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 *;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single *phase/
100A.

I'm sorry for you harry. *If true, just another sign of the
inadequacy of the Britts.

**There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? *The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. *What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. *200A are very
common too. *A friend has 300A. *All those are done
using single phase, nothing unusual at all.

A 15Kw three phase system here is just 22 A/phase as the voltage is
410v.
Putting loads like this on a single phase system causes voltages to
appear on the neutral which can upset RCD devices.- Hide quoted text -

- Show quoted text -

Only if the single phase system is half-assed. *Apparently
that must be the case. *And all this time I thought you Britts
were so superior. *Most houses only have a 100A service and
if you need more you have to go to 3 phase. *Must be a grand
place. *Or, more likely, your're just BSing as usual.

A 100A supply is 23Kw. here. Why would you need more than that?


23kW is only ~80 btu/hr ..... not much of a pool heater.

On May 25, 1:56*pm, DD_BobK wrote:
On May 24, 11:17*pm, harry wrote:





On May 24, 9:25*pm, "
wrote:

On May 24, 12:47*pm, harry wrote:

On May 24, 3:42*pm, "
wrote:

On May 24, 1:04*am, harry wrote:

On May 23, 6:12*pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46*am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). *I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. *We'll probably only use the pool on the weekends. *Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? *Is my thinking skewed? *Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event.

On May 25, 3:10*pm, wrote:
On Fri, 24 May 2013 23:17:08 -0700 (PDT), harry









wrote:
On May 24, 9:25 pm, "
wrote:
On May 24, 12:47 pm, harry wrote:

On May 24, 3:42 pm, "
wrote:

On May 24, 1:04 am, harry wrote:

On May 23, 6:12 pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46 am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. We'll probably only use the pool on the weekends. Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? Is my thinking skewed? Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event..
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated.. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that.
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall.
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 ;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single phase/
100A.

I'm sorry for you harry. If true, just another sign of the
inadequacy of the Britts.

There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. 200A are very
common too. A friend has 300A. All those are done
using single phase, nothing unusual at all.

A 15Kw three phase system here is just 22 A/phase as the voltage is
410v.
Putting loads like this on a single phase system causes voltages to
appear on the neutral which can upset RCD devices.- Hide quoted text -

- Show quoted text -

Only if the single phase system is half-assed. Apparently
that must be the case. And all this time I thought you Britts
were so superior. Most houses only have a 100A service and
if you need more you have to go to 3 phase. Must be a grand
place. Or, more likely, your're just BSing as usual.

A 100A supply is 23Kw. here. Why would you need more than that?

Oh, things like electric ovens, air conditioners (or heat pumps),
electric water heaters, clothes dryers. Any number of things that
makes life comfortable, which you Brits obviously haven't heard of.

Like I said in another post, I have two 150s (72kW). *In my other
house it's only a single 200A (48kW) entrance.

You never heard of diversity factor?
If you had 20Kw of electrical appliances turned on the house would be
uninhabitable in a couple of hours.

On May 25, 3:14*pm, wrote:
On Fri, 24 May 2013 23:15:35 -0700 (PDT), harry









wrote:
On May 24, 9:22 pm, "
wrote:
On May 24, 1:13 pm, harry wrote:

On May 24, 3:42 pm, "
wrote:

On May 24, 1:04 am, harry wrote:

On May 23, 6:12 pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46 am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. We'll probably only use the pool on the weekends. Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? Is my thinking skewed? Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event..
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated.. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that.
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall.
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 ;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single phase/
100A.

I'm sorry for you harry. If true, just another sign of the
inadequacy of the Britts.

There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. 200A are very
common too. A friend has 300A. All those are done
using single phase, nothing unusual at all.

Electric heating of swimming pools is virtually unheard of due to
cost, there is a gas supply to 99% of places.

It's not really electric heating. That terms is typically used
to refer to resistance heating. The pools use heat pumps,
which are referred to as heat pumps. If gas is the only
viable option in the UK, how do you explain this:

http://www.dreamheatpumps.co.uk/

http://www.ebay.co.uk/itm/350793470032

http://www.lighthousepools.co.uk/

Like I said, if they let you out of the nuthouse at
least once in a while, maybe you'd see some stuff.

Virtually never used.

Sure, who should we believe? You who doesn't even have
any experience with a pool or all the companies obviously
selling heat pump based heaters?

Most homes here have wet heating systems. This boiler can easily be
used to heat the pool via a heat exchanger.

What most do doesn't mean there isn't a viable market for heat
pump systems. Most pools here in the US don't have
heat pump systems either. Matters not a wit. If the
application is right, they can be the right choice.

Where there is no gas, either oil or propane is used.
Heat pumps are being offered in the last ten years or so but there are
icing problems on the evaporators in our climate.

Icing on a pool heat pump? Icing indeed!

Due to the climate, outdoor pools are unusual here, Of the few that
exist a tiny percentage are heated.
Indoor pools are obviously vastly more expensive and these too are
rare.
How many outdoor pools are there in Alaska?

Doesn't the evaporator in you freezer ice up you dolt?
Why therefore shouldn't the evaporator in any heat pump ice up?

Perhaps because the evaporator doesn't get cold enough? You do know
that outdoor pools are used during the summer? *Speaking of dolt! *Ads not by this site

IIt's down to air temperature and humidity and the temperature of the
refrigerant gases.

On May 25, 8:56*am, "
wrote:
On May 25, 11:49*am, Oren wrote:









On Sat, 25 May 2013 07:35:48 -0700 (PDT), "

wrote:
On May 25, 2:11 am, wrote:
On Fri, 24 May 2013 19:04:55 -0700 (PDT), "

wrote:
On May 24, 4:13 pm, Oren wrote:
On Fri, 24 May 2013 15:41:26 -0400, wrote:
On Fri, 24 May 2013 12:38:56 -0700, chaniarts
wrote:

On 5/24/2013 12:22 PM, Oren wrote:
On Fri, 24 May 2013 10:29:58 -0700, chaniarts
wrote:

No, there is no insulation between the pool and the ground. It doesn't get that cold down here for that kind of thing, I would think.

you'd be wrong. ground temp is always less than air temp, unless you're
living on a volcano. so, it's always a heat sink 24x7. insulation around
a pool is always a winner, but it's hard to put in after the pool is done.

I worked in pool construction as a teen, In Florida, no less. Not once
was insulation involved in the construction of the in ground pools.

The cement gunite is ~ 8 inches thick, full of steel rebar and
retains heat for some time.

cost.

yes it retains heat. but the earth is a pretty large heat sink, and
it'll win every time. otherwise ground loops for heating/cooling
exchangers wouldn't be an economic win.

i would bet that every pool north of 5 degrees of latitude would benefit
from insulation, most especially heated ones. no one wants to pay for
that up front.

Heating pools is fairly insignificant in Florida.

I'd go so far as to say the water table is warm. (seasonable)- Hide quoted text -

- Show quoted text -

Well, it certainly is more than 32F, but it is still below what you
would want far a swimming pool for at least 6 months every year. No
matter what, there is going to be a lot of heat loss into the ground,
and the ground is very wet/conductive in FL. You need to study the
air loss from the surface and the conducted loss thru the walls and
bottom of the pool to see where your emphasis should be, It is
conceivable that you should drain the pool, put insulation all around
the sides of the pool and then refill the pool.

Huh?
How do you get the insulation behind the concrete?

That would seem to be a good question

For that matter, if you have a liner based pool, I'm
not sure you could do much with that either. Not sure
what you have behind the liner, ie if there is room for
some kind of insulation, like expanded foam maybe?

A good question is why they don't insulate new pools?
If planned for as part of the construction there could be
room for sufficient insulation. *And while it would add to
the cost, you would think the payback would be pretty
reasonable, assuming you do some amount of pool
heating.

I can't come up with a single idea as to what the insulation would be.

It would have to:

- support the weight of a concrete pool or crack the pool

- last for ages under ground

- how would the water table impact the material

Now, on a casino roof top pool, it would seem there would be an easy
way.- Hide quoted text -

- Show quoted text -

I agree there are some issues. *But then insulation is used
with concrete pours for basements that are going to
be heated. *Not all the time, but I've seen it done on TV,
like This Old House, etc. *Google ICF concrete.

The whole thing of insulation UNDER concrete may seem a bit weird /
counter intuitive .....
did to me when I first was exposed to it.

My initial reaction to insulation under concrete was "how can that
work?"
Concrete is heavy, foam is weak.

BUT the numbers do work....

consider concrete pool 8' deep with a pool bottom 12" thick.

The weight of the concrete PLUS the weight of the water above (for a
1' square column)
is ~150lbs of concrete plus ~500 lbs of water, for a total of 650
lbs.

This may seem like a lot total weight but it works out to a stress of
only 4.5 lbs per square inch.... which is very low.
(The sideways compressive stress capacity of typical framing timber is
more like 400 psi...
so we're only asking the foam to be ~1% as strong as wood)

Soooo... the foam must be able to reliably support this low level of
stress with some sort of "safety factor"

Here's a foam for under concrete apps...
http://foamular.com/assets/0/144/172...f4b6a9fdf7.pdf

On May 25, 3:35*pm, wrote:
On Fri, 24 May 2013 23:17:08 -0700 (PDT), harry

wrote:
A 100A supply is 23Kw. here. Why would you need more than that?

11 WK spa heater, 15KW of residential heat, 5.5kw water heater, 8kw
range, 4.8 kw electric dryer and then you have your other loads.

It adds up pretty fast.

We have gas for all heating loads in 99% of homes.
All of the above would be gas fired here.

No-one uses electricity for heating unless there is absolutely no
other option.
And then is would be night time electricity on a cheaper rate.
Even then it would be more expensive than gas.

On May 25, 3:37*pm, wrote:
On Sat, 25 May 2013 10:14:31 -0400, wrote:
Why therefore shouldn't the evaporator in any heat pump ice up?

Perhaps because the evaporator doesn't get cold enough? You do know
that outdoor pools are used during the summer? *Speaking of dolt!

Harry lives in England
He is not sure what summer is.
That is why so many of his countrymen come here to Florida *;-)

If you are going to have a high coefficient of performance, the
evaporator will need to get cold.

http://en.wikipedia.org/wiki/Air_source_heat_pump#Usage
The outdoor section on some units may 'frost up' when there is
sufficient moisture in the air and outdoor temperature is between 0°C
and 5°C (32°F to 41°F)[citation needed]. This restricts air flow
across the outdoor coil. These units employ a defrost cycle where the
system switches temporarily to 'cooling' mode to move heat from the
home to the outdoor coil to melt the ice. This requires the
supplementary heater (resistance electric or gas) to activate. The
defrost cycle reduces the efficiency of the heat pump significantly,
although the newer (demand) systems are more intelligent and need to
defrost less. As temperatures drop below freezing the tendency for
frosting of the outdoor section decreases due to reduced humidity in
the air.

On Sat, 25 May 2013 10:37:24 -0400, wrote:

On Sat, 25 May 2013 10:14:31 -0400, wrote:

Why therefore shouldn't the evaporator in any heat pump ice up?

Perhaps because the evaporator doesn't get cold enough? You do know
that outdoor pools are used during the summer? Speaking of dolt!

Harry lives in England

What a drag that must be.

He is not sure what summer is.

He has constant dark clouds, Never sees the bright side of things.

That is why so many of his countrymen come here to Florida ;-)

The smart ones, for sure!

On May 25, 6:56*pm, DD_BobK wrote:
On May 24, 11:17*pm, harry wrote:









On May 24, 9:25*pm, "
wrote:

On May 24, 12:47*pm, harry wrote:

On May 24, 3:42*pm, "
wrote:

On May 24, 1:04*am, harry wrote:

On May 23, 6:12*pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46*am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). *I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. *We'll probably only use the pool on the weekends. *Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? *Is my thinking skewed? *Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event.

On May 25, 2:31*pm, harry wrote:
On May 25, 3:35*pm, wrote:

On Fri, 24 May 2013 23:17:08 -0700 (PDT), harry

wrote:
A 100A supply is 23Kw. here. Why would you need more than that?

11 WK spa heater, 15KW of residential heat, 5.5kw water heater, 8kw
range, 4.8 kw electric dryer and then you have your other loads.

It adds up pretty fast.

We have gas for all heating loads in 99% of homes.
All of the above would be gas fired here.



What you have or don't have has no impact on what
the rest of the world, like the USA. You already told us
that England is soscrewed up that you can't get more than
a 100A service unless you go to three phase. Not that I'm
buying that, but if it's true, it really is a screwy place indeed.



No-one uses electricity for heating unless there is absolutely no
other option.


Yawn.... The same tired canard. "Electricity" for heating
implies ordinary resistance heating. "Heat pumps" are
what is being discussed here.

On May 25, 2:37*pm, harry wrote:
On May 25, 3:37*pm, wrote:

On Sat, 25 May 2013 10:14:31 -0400, wrote:
Why therefore shouldn't the evaporator in any heat pump ice up?

Perhaps because the evaporator doesn't get cold enough? You do know
that outdoor pools are used during the summer? *Speaking of dolt!

Harry lives in England
He is not sure what summer is.
That is why so many of his countrymen come here to Florida *;-)

If you are going to have a high coefficient of performance, the
evaporator will need to get cold.

http://en.wikipedia.org/wiki/Air_source_heat_pump#Usage
The outdoor section on some units may 'frost up' when there is
sufficient moisture in the air and outdoor temperature is between 0°C
and 5°C (32°F to 41°F)[citation needed]. This restricts air flow
across the outdoor coil. These units employ a defrost cycle where the
system switches temporarily to 'cooling' mode to move heat from the
home to the outdoor coil to melt the ice. This requires the
supplementary heater (resistance electric or gas) to activate. The
defrost cycle reduces the efficiency of the heat pump significantly,
although the newer (demand) systems are more intelligent and need to
defrost less. As temperatures drop below freezing the tendency for
frosting of the outdoor section decreases due to reduced humidity in
the air.

You really are the village idiot. You're own source above talks
about icing up when the outside air is 32 to 41F. We're talking
about a pool in FLORIDA. You really think people in FL are
going to heat a pool on the rare occasions that it's in the 30s
outside so that this is a real issue? Even in more northern
climates, very few people heat pools when it's in the 30s
and those that choose to, simply wouldn't use a heat pump
anyway because it's not intended for, practical, good at those
applications. Good grief!

DD_BobK wrote:
On May 25, 8:56 am, "
wrote:
On May 25, 11:49 am, Oren wrote:









On Sat, 25 May 2013 07:35:48 -0700 (PDT), "

wrote:
On May 25, 2:11 am, wrote:
On Fri, 24 May 2013 19:04:55 -0700 (PDT),
"

wrote:
On May 24, 4:13 pm, Oren wrote:
On Fri, 24 May 2013 15:41:26 -0400, wrote:
On Fri, 24 May 2013 12:38:56 -0700, chaniarts
wrote:

On 5/24/2013 12:22 PM, Oren wrote:
On Fri, 24 May 2013 10:29:58 -0700, chaniarts
wrote:

No, there is no insulation between the pool and the
ground. It doesn't get that cold down here for that kind
of thing, I would think.

you'd be wrong. ground temp is always less than air temp,
unless you're living on a volcano. so, it's always a heat
sink 24x7. insulation around a pool is always a winner, but
it's hard to put in after the pool is done.

I worked in pool construction as a teen, In Florida, no
less. Not once was insulation involved in the construction
of the in ground pools.

The cement gunite is ~ 8 inches thick, full of steel rebar
and retains heat for some time.

cost.

yes it retains heat. but the earth is a pretty large heat
sink, and it'll win every time. otherwise ground loops for
heating/cooling exchangers wouldn't be an economic win.

i would bet that every pool north of 5 degrees of latitude
would benefit from insulation, most especially heated ones.
no one wants to pay for that up front.

Heating pools is fairly insignificant in Florida.

I'd go so far as to say the water table is warm. (seasonable)-
Hide quoted text -

- Show quoted text -

Well, it certainly is more than 32F, but it is still below what
you would want far a swimming pool for at least 6 months every
year. No matter what, there is going to be a lot of heat loss
into the ground, and the ground is very wet/conductive in FL.
You need to study the air loss from the surface and the
conducted loss thru the walls and bottom of the pool to see
where your emphasis should be, It is conceivable that you should
drain the pool, put insulation all around the sides of the pool
and then refill the pool.

Huh?
How do you get the insulation behind the concrete?

That would seem to be a good question

For that matter, if you have a liner based pool, I'm
not sure you could do much with that either. Not sure
what you have behind the liner, ie if there is room for
some kind of insulation, like expanded foam maybe?

A good question is why they don't insulate new pools?
If planned for as part of the construction there could be
room for sufficient insulation. And while it would add to
the cost, you would think the payback would be pretty
reasonable, assuming you do some amount of pool
heating.

I can't come up with a single idea as to what the insulation would
be.

It would have to:

- support the weight of a concrete pool or crack the pool

- last for ages under ground

- how would the water table impact the material

Now, on a casino roof top pool, it would seem there would be an easy
way.- Hide quoted text -

- Show quoted text -

I agree there are some issues. But then insulation is used
with concrete pours for basements that are going to
be heated. Not all the time, but I've seen it done on TV,
like This Old House, etc. Google ICF concrete.

The whole thing of insulation UNDER concrete may seem a bit weird /
counter intuitive .....
did to me when I first was exposed to it.

My initial reaction to insulation under concrete was "how can that
work?"
Concrete is heavy, foam is weak.

BUT the numbers do work....

consider concrete pool 8' deep with a pool bottom 12" thick.

The weight of the concrete PLUS the weight of the water above (for a
1' square column)
is ~150lbs of concrete plus ~500 lbs of water, for a total of 650
lbs.

This may seem like a lot total weight but it works out to a stress of
only 4.5 lbs per square inch.... which is very low.
(The sideways compressive stress capacity of typical framing timber is
more like 400 psi...
so we're only asking the foam to be ~1% as strong as wood)

Soooo... the foam must be able to reliably support this low level of
stress with some sort of "safety factor"

Here's a foam for under concrete apps...
http://foamular.com/assets/0/144/172...f4b6a9fdf7.pdf

FWIW, I got 6" of extruded Styrene under my 4' deep concrete hottub, which has
held up fine for 20 years or so, so far.

On May 25, 8:15*pm, "Bob F" wrote:
GIANT SNIP

http://foamular.com/assets/0/144/172...4f08-bebe-71f4...

FWIW, I got 6" of extruded Styrene under my 4' deep concrete hottub, which has
held up fine for 20 years or so, so far.

FWIW, I got 6" of extruded Styrene under my 4' deep concrete hottub,
which has
held up fine for 20 years or so, so far.

+1

Great first hand data!

On Sat, 25 May 2013 11:24:04 -0700 (PDT), harry
wrote:

On May 25, 3:10*pm, wrote:
On Fri, 24 May 2013 23:17:08 -0700 (PDT), harry









wrote:
On May 24, 9:25 pm, "
wrote:
On May 24, 12:47 pm, harry wrote:

On May 24, 3:42 pm, "
wrote:

On May 24, 1:04 am, harry wrote:

On May 23, 6:12 pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46 am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. We'll probably only use the pool on the weekends. Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? Is my thinking skewed? Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event.
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that.
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall.
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 ;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single phase/
100A.

I'm sorry for you harry. If true, just another sign of the
inadequacy of the Britts.

There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. 200A are very
common too. A friend has 300A. All those are done
using single phase, nothing unusual at all.

A 15Kw three phase system here is just 22 A/phase as the voltage is
410v.
Putting loads like this on a single phase system causes voltages to
appear on the neutral which can upset RCD devices.- Hide quoted text -

- Show quoted text -

Only if the single phase system is half-assed. Apparently
that must be the case. And all this time I thought you Britts
were so superior. Most houses only have a 100A service and
if you need more you have to go to 3 phase. Must be a grand
place. Or, more likely, your're just BSing as usual.

A 100A supply is 23Kw. here. Why would you need more than that?

Oh, things like electric ovens, air conditioners (or heat pumps),
electric water heaters, clothes dryers. Any number of things that
makes life comfortable, which you Brits obviously haven't heard of.

Like I said in another post, I have two 150s (72kW). *In my other
house it's only a single 200A (48kW) entrance.

You never heard of diversity factor?

Sounds like a leftist plot.

Yet you ask why someone would need more than 100A. Moron!

If you had 20Kw of electrical appliances turned on the house would be
uninhabitable in a couple of hours.

Idiot. Much of the year, if my "20kW electrical appliances" *AREN'T*
turned on, the house would be uninhabitable in a couple of hours.

On Sat, 25 May 2013 11:27:55 -0700 (PDT), harry
wrote:

On May 25, 3:14*pm, wrote:
On Fri, 24 May 2013 23:15:35 -0700 (PDT), harry









wrote:
On May 24, 9:22 pm, "
wrote:
On May 24, 1:13 pm, harry wrote:

On May 24, 3:42 pm, "
wrote:

On May 24, 1:04 am, harry wrote:

On May 23, 6:12 pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46 am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. We'll probably only use the pool on the weekends. Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? Is my thinking skewed? Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event.
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that.
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall.
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 ;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single phase/
100A.

I'm sorry for you harry. If true, just another sign of the
inadequacy of the Britts.

There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. 200A are very
common too. A friend has 300A. All those are done
using single phase, nothing unusual at all.

Electric heating of swimming pools is virtually unheard of due to
cost, there is a gas supply to 99% of places.

It's not really electric heating. That terms is typically used
to refer to resistance heating. The pools use heat pumps,
which are referred to as heat pumps. If gas is the only
viable option in the UK, how do you explain this:

http://www.dreamheatpumps.co.uk/

http://www.ebay.co.uk/itm/350793470032

http://www.lighthousepools.co.uk/

Like I said, if they let you out of the nuthouse at
least once in a while, maybe you'd see some stuff.

Virtually never used.

Sure, who should we believe? You who doesn't even have
any experience with a pool or all the companies obviously
selling heat pump based heaters?

Most homes here have wet heating systems. This boiler can easily be
used to heat the pool via a heat exchanger.

What most do doesn't mean there isn't a viable market for heat
pump systems. Most pools here in the US don't have
heat pump systems either. Matters not a wit. If the
application is right, they can be the right choice.

Where there is no gas, either oil or propane is used.
Heat pumps are being offered in the last ten years or so but there are
icing problems on the evaporators in our climate.

Icing on a pool heat pump? Icing indeed!

Due to the climate, outdoor pools are unusual here, Of the few that
exist a tiny percentage are heated.
Indoor pools are obviously vastly more expensive and these too are
rare.
How many outdoor pools are there in Alaska?

Doesn't the evaporator in you freezer ice up you dolt?
Why therefore shouldn't the evaporator in any heat pump ice up?

Perhaps because the evaporator doesn't get cold enough? You do know
that outdoor pools are used during the summer? *Speaking of dolt! *Ads not by this site

IIt's down to air temperature and humidity and the temperature of the
refrigerant gases.

Idiot! Who is swimming when the air temperature is near freezing? You
probably would; no brain = no pain.

On 5/25/2013 11:24 AM, harry wrote:
On May 25, 3:10 pm, wrote:
On Fri, 24 May 2013 23:17:08 -0700 (PDT), harry









wrote:
On May 24, 9:25 pm, "
wrote:
On May 24, 12:47 pm, harry wrote:

On May 24, 3:42 pm, "
wrote:

On May 24, 1:04 am, harry wrote:

On May 23, 6:12 pm, wrote:

On Thu, 23 May 2013 00:12:12 -0700 (PDT), harry

wrote:
On May 23, 2:46 am, wrote:
I'm thinking of installing a heat pump for my 15x30 pool.

I'm told that the correct unit for my needs (an Aquacal TropiCal) puts out 112,000 BTUs (40 amps/5.8 KW). I'm thinking that a larger unit that puts out 141,000 BTUs (50 amps/6.4KW), would heat the pool quicker and require less time on, thus use, in theory, less electricity - but it's about $500 more expensive than the small

unit. We'll probably only use the pool on the weekends. Not sure how long it will take to break even on this with running it for only a couple days per week.

Anybody have any thoughts or opinions about this? Is my thinking skewed? Is it worth the extra cost?

Thanks!Ads not by this site

You would be better getting some sort of solar heater.

Running a swimming pool is always going to be expensive.
Gas would be far cheaper than electricity.
Electricity is the worst possible option.
If your pool is near the house you may be able to use the home
heating furnace if you have a wet system.
You need a good insulated pool cover. Ideally there should
be insulation between the pool and the ground too.

The economics of turning a pool heating off are very dodgy
as it takes days for the pool to reheat.
Reducing temperature may be an option.

Your incoming power supply may not be big enough in any event.
You may need a three phase supply.

Harry is right, solar is the way to go but if you are very far north,
that may still not be enough.

Most of the pools in my neighborhood (SW Fla) are solar heated. The
practical limit for an uncovered pool is really only about 10 degrees
above the average daily ambient temp. You may end up with 80 degree
water in the afternoon on a 70 degree day but by morning that will be
back down in the low 70s. A cover makes a huge difference in that.
My neighbor across the street has more collector area than pool
surface and they can hold 86 or higher most of the winter (45-50f at
night)
When it gets much colder than that, they don't do as well.

I have less collector than pool area and no cover. The only thing
solar does for me in knock the chill off in the spring and fall.
I changed the plumbing so I can switch over to the spa. THAT is a
heluva deal.
When the solars are useless on the pool, I can still get the spa up in
the high 80s or low 90s before I kick on the heater.
In the spring and fall, I can get all the heat I need from the solars
in the day and only need the heater to maintain the heat until I am
done with it
We do not heat the spa with the heater unless we are in it.

Typically the only controller on a solar pool heater is a timer on the
pump.
I am going to tie the spa solar into the thermostat tho because this
spring I caught it at 120 ;-)

Harry You virtually never see 3 phase at a residence but we do see 400
amp single phase service on a big house.

As gee whiz info, my wife's country club has 7 heated pools,
uncovered.
They can't hold the temp with 10 ton heat pumps on the small pools if
we have a cold snap. The big pool has 30 tons

I will try to get the cost, they are all on separate meters.

Most houses here have electricity here is at 230volts/single phase/
100A.

I'm sorry for you harry. If true, just another sign of the
inadequacy of the Britts.

There is no 120 volts except on construction sites when step

down transformers are used.

Who cares? The pool heat pumps all run on 240V.

However if you have more than say 15Kw continuous heating, you will be
expected to get three phase (depending on location).

That's just 62 amps. What exactly is the problem with
having a 150A service that makes 3 phase necessary?
150A services are very common here, the min pretty
much that's put in today for a house. 200A are very
common too. A friend has 300A. All those are done
using single phase, nothing unusual at all.

A 15Kw three phase system here is just 22 A/phase as the voltage is
410v.
Putting loads like this on a single phase system causes voltages to
appear on the neutral which can upset RCD devices.- Hide quoted text -

- Show quoted text -

Only if the single phase system is half-assed. Apparently
that must be the case. And all this time I thought you Britts
were so superior. Most houses only have a 100A service and
if you need more you have to go to 3 phase. Must be a grand
place. Or, more likely, your're just BSing as usual.

A 100A supply is 23Kw. here. Why would you need more than that?

Oh, things like electric ovens, air conditioners (or heat pumps),
electric water heaters, clothes dryers. Any number of things that
makes life comfortable, which you Brits obviously haven't heard of.

Like I said in another post, I have two 150s (72kW). In my other
house it's only a single 200A (48kW) entrance.

You never heard of diversity factor?
If you had 20Kw of electrical appliances turned on the house would be
uninhabitable in a couple of hours.


location. location. location.

i have an 8kw ceramics kiln, and 10.5 tons of a/c on my house. they
frequently are all on at the same time, and my wife can still turn on
the stove. i can't imagine being limited to 100a in today's day and age,
and would never buy a house that didn't have at least 200a. my next
house will probably have at least 300a.

On Tue, 28 May 2013 17:45:50 -0400, wrote:

On Tue, 28 May 2013 09:30:39 -0400, wrote:

Idiot! Who is swimming when the air temperature is near freezing?

Canadians

Outside?

BTW here is the electric bill for a small commercial pool with a 7.5
ton heat pump.

date...........................days..........KWH. ....
05/07/2013 32 2776 $275.92 Electric Bill
04/05/2013 29 3634 $358.36 Electric Bill
03/07/2013 28 3906 $384.64 Electric Bill
02/07/2013 30 4562 $442.98 Electric Bill
01/08/2013 32 4645 $450.90 Electric Bill
12/07/2012 30 4210 $428.26 Electric Bill
11/07/2012 30 4117 $418.96 Electric Bill
10/08/2012 31 2637 $270.97 Electric Bill
09/07/2012 31 1793 $186.52 Electric Bill
08/07/2012 29 1672 $174.41 Electric Bill
07/09/2012 32 1847 $191.92 Electric Bill
06/07/2012 31 2205 $228.44 Electric Bill
05/07/2012 31 3693 $377.66 Electric Bill
04/06/2012 30 2803 $287.19 Electric Bill
03/07/2012 29 3877 $394.43 Electric Bill
02/07/2012 29 4746 $481.20 Electric Bill
01/09/2012 33 4771 $483.70 Electric Bill
12/07/2011 30 4098 $433.17 Electric Bill
11/07/2011 31 4124 $435.87 Electric Bill
10/07/2011 29 1711 $185.12 Electric Bill
09/08/2011 34 2021 $217.31 Electric Bill
08/05/2011 28 1670 $180.97 Electric Bill
07/08/2011 31 1838 $198.44 Electric Bill
06/07/2011 32 1897 $204.57 Electric Bill

On Thu, 23 May 2013 05:44:59 -0700 (PDT),
wrote:

No, there is no insulation between the pool and the ground. It doesn't get that cold down here for that kind of thing, I would think.

The ground temperature in Florida is around 70F. That
is the temperature of all those beautiful Florida springs. You want
your pool quite a bit warmer than that. Water and concrete conduct
heat well -- not like metal but well enough for insulation to make a
big difference.

In the long run, the installation cost of solar (with virtually no
operating cost) is tiny compared with the operating cost of a heat
pump, so it's worth doing even if you do the heat pump also. Every bit
of heat added by the sun doesn't have to be added by the heat pump.
And you say tile -- if you have a concrete tile roof, then you should
not be worrying about the weight of the solar heat system, which does
not have much water in it at any given time. Just make sure to use a
reputable installer so they don't damage the tile.

The larger unit will run less, but when you buy electricity, you pay
for energy used. Energy = power times time. You have a power rating in
KW -- that's power input and is what you pay for. You have another
power rating in BTUs/hour -- that's power output and is what you get
in your pool. Both the power output and the power input are different
on the two units, so a difference in run time alone doesn't mean much
by itself. The ratio of the power outputs (in kiloBTU/hour) to the
power inputs (in KW) is 20.69 for the smaller unit and 22.03 for the
larger unit. Thus the larger unit is slightly (about 6%) more
efficient. That's the figure you should use for deciding which is
better in terms of energy use. It may take a long time for the greater
efficiency to compensate for the greater initial outlay.

Other than that, everything everybody else said ...

Edward

On Fri, 24 May 2013 09:47:25 -0700 (PDT), harry
wrote:

Putting loads like this on a single phase system causes voltages to
appear on the neutral which can upset RCD devices.

If a 240V device is connected to a neutral, then there's an
electrician whose license needs to be revoked. Retroactively.

What's usually called single phase is really two-phase -- two phases
180 degrees apart. Three-phase has the phases 120 degrees apart. Two
phase is fine for balancing. You really only need three-phase for
certain kinds of electric motors, which for obvious reasons aren't put
in appliances destined for residential use.

With either 2-phase or 3-phase, appliances which need 120V are
attached to one phase and a neutral. With 2-phase, appliances which
need 240V are attached to both phases. With 3-phase, appliances which
need 208V are attached to any two phases (dig out your trigonometry to
figure out where the 208V comes from). Three-phase motors are more
complicated ...

Edward

On May 30, 4:58*pm, Edward Reid
wrote:
On Thu, 23 May 2013 05:44:59 -0700 (PDT),
wrote:

No, there is no insulation between the pool and the ground. *It doesn't get that cold down here for that kind of thing, I would think.

The ground temperature in Florida is around 70F. That
is the temperature of all those beautiful Florida springs. You want
your pool quite a bit warmer than that. Water and concrete conduct
heat well -- not like metal but well enough for insulation to make a
big difference.

In the long run, the installation cost of solar (with virtually no
operating cost) is tiny compared with the operating cost of a heat
pump, so it's worth doing even if you do the heat pump also. Every bit
of heat added by the sun doesn't have to be added by the heat pump.
And you say tile -- if you have a concrete tile roof, then you should
not be worrying about the weight of the solar heat system, which does
not have much water in it at any given time. Just make sure to use a
reputable installer so they don't damage the tile.

The larger unit will run less, but when you buy electricity, you pay
for energy used. Energy = power times time. You have a power rating in
KW -- that's power input and is what you pay for. You have another
power rating in BTUs/hour -- that's power output and is what you get
in your pool. Both the power output and the power input are different
on the two units, so a difference in run time alone doesn't mean much
by itself. The ratio of the power outputs (in kiloBTU/hour) to the
power inputs (in KW) is 20.69 for the smaller unit and 22.03 for the
larger unit. Thus the larger unit is slightly (about 6%) more
efficient. That's the figure you should use for deciding which is
better in terms of energy use. It may take a long time for the greater
efficiency to compensate for the greater initial outlay.

Other than that, everything everybody else said ...

Edward

Agree with everything you say, except the power output/input ratio.
No way you can get 20X the energy
out of a heat pump that goes into it. Something like 4X
is more like it. If you got anywhere near that amount
of heat, everyone would be using one instead of gas, oil,
etc.

On Thu, 30 May 2013 17:07:31 -0400, Edward Reid
wrote:

On Fri, 24 May 2013 09:47:25 -0700 (PDT), harry
wrote:

Putting loads like this on a single phase system causes voltages to
appear on the neutral which can upset RCD devices.

If a 240V device is connected to a neutral, then there's an
electrician whose license needs to be revoked. Retroactively.

Are ovens and clothes dryers 240V? Every modern installation has a
neutral.

What's usually called single phase is really two-phase -- two phases
180 degrees apart.

Wrong. It's really a single split phase.

Three-phase has the phases 120 degrees apart. Two
phase is fine for balancing. You really only need three-phase for
certain kinds of electric motors, which for obvious reasons aren't put
in appliances destined for residential use.

Completely wrong. Three phase isn't put in appliances for residential
use because three phase isn't installed in residences in the US. In
many places it's not even available at the street in residential
neighborhoods.

With either 2-phase or 3-phase, appliances which need 120V are
attached to one phase and a neutral. With 2-phase, appliances which
need 240V are attached to both phases. With 3-phase, appliances which
need 208V are attached to any two phases (dig out your trigonometry to
figure out where the 208V comes from). Three-phase motors are more
complicated ...

Wrong. Don't give up your day job.

On Thu, 30 May 2013 14:52:21 -0700 (PDT), "
wrote:

Agree with everything you say, except the power output/input ratio.
No way you can get 20X the energy
out of a heat pump that goes into it.

The ratios I gave were BTUs/hour over watts. I didn't bother with the
conversion factor to make it a real output/input ratio (for example
watts out over watts in) because the only point was to compare the two
units.

Thanks for reading carefully!

Edward

On May 31, 12:36*pm, wrote:
On Thu, 30 May 2013 17:07:31 -0400, Edward Reid

wrote:
On Fri, 24 May 2013 09:47:25 -0700 (PDT), harry
wrote:

Putting loads like this on a single phase system causes voltages to
appear on the neutral which can upset RCD devices.

If a 240V device is connected to a neutral, then there's an
electrician whose license needs to be revoked. Retroactively.

Are ovens and clothes dryers 240V? *Every modern installation has a
neutral.

What's usually called single phase is really two-phase -- two phases
180 degrees apart.

Wrong. *It's really a single split phase.

That is what it's called in terms of power distribution,
but he is correct that it can be
viewed as two phases. Graph the waveforms of the
two hots and you clearly have two different voltage
waveforms present, with one 180deg off from the other.
Graph a 3 phase and you have 3 seperate waveforms,
off by 120deg.






Three-phase has the phases 120 degrees apart. Two
phase is fine for balancing. You really only need three-phase for
certain kinds of electric motors, which for obvious reasons aren't put
in appliances destined for residential use.

Completely wrong. *Three phase isn't put in appliances for residential
use because three phase isn't installed in residences in the US. *In
many places it's not even available at the street in residential
neighborhoods.

Sure 3 phase isn't available in homes. But even if it was, as he
correctly points out, there is no need for it with small, cheap
fractional horsepower motors like found in home appliances.

wrote in message
...
Are ovens and clothes dryers 240V? Every modern installation has a
neutral.

What's usually called single phase is really two-phase -- two phases
180 degrees apart.

Wrong. It's really a single split phase.

Three-phase has the phases 120 degrees apart. Two
phase is fine for balancing. You really only need three-phase for
certain kinds of electric motors, which for obvious reasons aren't put
in appliances destined for residential use.

Completely wrong. Three phase isn't put in appliances for residential
use because three phase isn't installed in residences in the US. In
many places it's not even available at the street in residential
neighborhoods.

With either 2-phase or 3-phase, appliances which need 120V are
attached to one phase and a neutral. With 2-phase, appliances which
need 240V are attached to both phases. With 3-phase, appliances which
need 208V are attached to any two phases (dig out your trigonometry to
figure out where the 208V comes from). Three-phase motors are more
complicated ...

Wrong. Don't give up your day job.

Another US power ****ing contest.

The normal home service of 240 volts is single phase with a center tap.
There are actually some real 2 phase systems, but not in most of the homes.

I would like to see how one plans on hooking up a 3 phase 208 volt appliance
to only two of the phases of a 3 phase system..

In areas that do have 3 phase 208 volt systems, it is easy to get 120 volts.
That is from one of the phases to a center of a Y network. Same as you get
277 volts single phase from a 480 volt 3 phase system that is common in
large plants.

wrote in :

With either 2-phase or 3-phase, appliances which need 120V are
attached to one phase and a neutral. With 2-phase, appliances which
need 240V are attached to both phases. With 3-phase, appliances which
need 208V are attached to any two phases (dig out your trigonometry to
figure out where the 208V comes from). Three-phase motors are more
complicated ...

Wrong. Don't give up your day job.


Completely wrong. Stick to jerking off and leave the electrical to guys who
know about it.

On Fri, 31 May 2013 12:36:49 -0400, wrote:
Are ovens and clothes dryers 240V? Every modern installation has a
neutral.

Yes, they are 240V. (At least in the US. My comments apply to the US.
All these can be built for 120V, or for 12V or for 1200V, but 240V is
a good compromise for minimizing the wire diameter needed and
minimizing the risk from high voltage in a residence.)

Most ovens and dryers will have a neutral run to them, but that's
because they are multiple appliances in a single box. Specifically,
they are a light bulb, a heating element, an electronic controller (in
modern units), and in many cases a fan. The heating element is 240V
and is not attached to the neutral. The light bulb is 120V and is
attached to the neutral and one of the hot legs. Fans may vary but
will be one of the two. The neutral is not used for the 240V part.

The compressor side of a split system A/C, or a package unit A/C or
heat pump, may well have only the two hot legs and no neutral. It
contains only the compressor and probably a heat exchanger fan, and
these can both be 240V. It might contain electronics, but the
electronics are fed through a step-down transformer within the unit
anyway.

In all of these cases the major load -- the heating element for ovens
and dryers, the compressor and probably the heat exchanger fan in A/C
compressors -- uses the two hot legs and not the neutral, and thus is
incapable of causing an imbalance, which was the comment I was
responding to.

Edward

On Thu, 23 May 2013 06:25:24 -0700 (PDT), "
wrote:

Yes, it will be on for less time, but it will also be
using proportionately more electricity than the smaller
unit while it's running. There isn't a free lunch here.
The real advantage of the larger one is that it will heat
the pool faster

All true. However, based on the OP's posted numbers, the larger unit
is slightly more efficient, roughly 6% more efficient. But that
doesn't change what you say -- running for less time isn't a savings
in and of itself.

Edward

On Fri, 24 May 2013 14:13:20 -0700, Oren wrote:
I'd go so far as to say the water table is warm. (seasonable)

More than a foot or two down, the ground water temperature in Florida
is pretty stable. Yes, the ground gets a lot more sun in summer, but
the water moves easily through the abundant sand and (farther down)
limestone. As a result, at the bottom of a swimming pool, it's going
to be close to 68F to 72F year round -- the same temperature as
Florida's many high-volume springs.

Edward

On Fri, 31 May 2013 13:14:23 -0400, "Ralph Mowery"
wrote:


wrote in message
.. .
Are ovens and clothes dryers 240V? Every modern installation has a
neutral.

What's usually called single phase is really two-phase -- two phases
180 degrees apart.

Wrong. It's really a single split phase.

Three-phase has the phases 120 degrees apart. Two
phase is fine for balancing. You really only need three-phase for
certain kinds of electric motors, which for obvious reasons aren't put
in appliances destined for residential use.

Completely wrong. Three phase isn't put in appliances for residential
use because three phase isn't installed in residences in the US. In
many places it's not even available at the street in residential
neighborhoods.

With either 2-phase or 3-phase, appliances which need 120V are
attached to one phase and a neutral. With 2-phase, appliances which
need 240V are attached to both phases. With 3-phase, appliances which
need 208V are attached to any two phases (dig out your trigonometry to
figure out where the 208V comes from). Three-phase motors are more
complicated ...

Wrong. Don't give up your day job.

Another US power ****ing contest.

If you don't like facts, please don't confuse others with your
bull****.

The normal home service of 240 volts is single phase with a center tap.
There are actually some real 2 phase systems, but not in most of the homes.

Show me one.

I would like to see how one plans on hooking up a 3 phase 208 volt appliance
to only two of the phases of a 3 phase system..

Three phase? All three present. Easy, a rotary phase converter (AKA
3-phase motor).

In areas that do have 3 phase 208 volt systems, it is easy to get 120 volts.
That is from one of the phases to a center of a Y network. Same as you get
277 volts single phase from a 480 volt 3 phase system that is common in
large plants.

Such are the shifting goal posts...

On 31 May 2013 18:01:11 GMT, JoeBro wrote:

wrote in :

With either 2-phase or 3-phase, appliances which need 120V are
attached to one phase and a neutral. With 2-phase, appliances which
need 240V are attached to both phases. With 3-phase, appliances which
need 208V are attached to any two phases (dig out your trigonometry to
figure out where the 208V comes from). Three-phase motors are more
complicated ...

Wrong. Don't give up your day job.


Completely wrong. Stick to jerking off and leave the electrical to guys who
know about it.

Idiot. I am an EE.

On Fri, 31 May 2013 15:18:28 -0400, Edward Reid
wrote:

On Fri, 31 May 2013 12:36:49 -0400, wrote:
Are ovens and clothes dryers 240V? Every modern installation has a
neutral.

Yes, they are 240V. (At least in the US. My comments apply to the US.
All these can be built for 120V, or for 12V or for 1200V, but 240V is
a good compromise for minimizing the wire diameter needed and
minimizing the risk from high voltage in a residence.)

True but irrelevant.

Most ovens and dryers will have a neutral run to them, but that's
because they are multiple appliances in a single box. Specifically,
they are a light bulb, a heating element, an electronic controller (in
modern units), and in many cases a fan. The heating element is 240V
and is not attached to the neutral. The light bulb is 120V and is
attached to the neutral and one of the hot legs. Fans may vary but
will be one of the two. The neutral is not used for the 240V part.

True but irrelevant. They *are*.

The compressor side of a split system A/C, or a package unit A/C or
heat pump, may well have only the two hot legs and no neutral. It
contains only the compressor and probably a heat exchanger fan, and
these can both be 240V. It might contain electronics, but the
electronics are fed through a step-down transformer within the unit
anyway.

True, but also irrelevant.

In all of these cases the major load -- the heating element for ovens
and dryers, the compressor and probably the heat exchanger fan in A/C
compressors -- uses the two hot legs and not the neutral, and thus is
incapable of causing an imbalance, which was the comment I was
responding to.

Did you have a point?

On Wed, 05 Jun 2013 13:04:23 -0400, wrote:
Did you have a point?

A point? This is Usenet. Wash your mouth out with soap. ;-)

Edward

wrote in :

On 31 May 2013 18:01:11 GMT, JoeBro wrote:

wrote in
m:

With either 2-phase or 3-phase, appliances which need 120V are
attached to one phase and a neutral. With 2-phase, appliances which
need 240V are attached to both phases. With 3-phase, appliances
which need 208V are attached to any two phases (dig out your
trigonometry to figure out where the 208V comes from). Three-phase
motors are more complicated ...

Wrong. Don't give up your day job.


Completely wrong. Stick to jerking off and leave the electrical to
guys who know about it.

Idiot. I am an EE.


Well then, you are an idiot EE. There are lots of them in that field.