On 10/10/2015 3:43 PM, Stormin Mormon wrote:
On 10/10/2015 2:12 PM, Muggles wrote:
Does anyone know if heating tapes would work for this or not?


Doubt it. The common heat tapes are designed to keep water
(barely) over the freezing temp. I'd expect them to work
well below the 60F you want.

With this much water, I'd check with pet stores and see
what they think. Propane is usually cheaper than electric
as a fuel source.

Perhaps a propane residential water heater, and tempering
valve?

Would a water heater like that end up costing more in powering it?


My experience with heat, is that propane is
cheaper than electric. In any, or, whatever
form.


ok thanks for the info.

--
Maggie

On 10/10/2015 4:21 PM, Tekkie® wrote:
Muggles posted for all of us...



We're re-building our hoop green house and using wood this time. We
have a aquaponics system where we raise fish, pump the fish water into
grow beds so the plants and plant media can filter the water, pump that
water into a sump and then that water goes to a large rock and sand
filter before it's pumped back into the fish tanks.

We're looking for a way to keep the water in the tanks warm in the
winter without it costing us an arm and a leg to heat the green house
itself. We're going to have about 800 to 1000 gallons of water in the
green house tanks, plus have passive solar heat from the ground that'll
have a thick layer of gravel in addition to having windows at the proper
angle to capture the winter sunlight and heat. We'll also have vents and
windows we can open at the peak of the green house to vent moisture and
too much hot air when needed on warmer days.

The problem is that if we heat the greenhouse along with using water
tank heaters the temps can drop dramatically in the greenhouse and
plants and fish don't do well if the temps are too drastic at night, so
I was thinking of using heat cables/tapes around the pvc pipes that
connect all the water flowing from tanks to plants to sump to filter vs.
using in tank water heaters.

We're also hoping for a solution that'll cost less to power and at the
same time keep the temps more stable in the green house. All the walls
and roofs are being insulated, too.

Does anyone know if heating tapes would work for this or not?

I don't think the pvc pipe would be a good conductor of the heat given off
by the tape. Perhaps heater in the fish tank would be best.


Right now we have some large aquarium heaters, but they use a lot of
electricity.

--
Maggie

On 10/10/2015 7:07 PM, mike wrote:
On 10/10/2015 9:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or heard of
them
before. How efficient are they? I'm looking for any idea that might
work.

Eventually, we're installing some solar panels to run anything we might
need in the green house, but right now it's all on the grid to the more
efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

I don't know anything about farming fish, but don't you need
some water/air exchange to keep the oxygen level tolerable to the fish.
If you just block the surface, what keeps the fish alive?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!



We have air bubblers in the tanks. They work even if the tanks are
covered.

--
Maggie

On 10/10/2015 10:28 AM, Stormin Mormon wrote:
On 10/10/2015 12:48 PM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!


I'd have to look it up, but I think the latent
heat of fusion is 86 BTU per pound, and the
heat of vaporization is about 550. But, it's
been a long time since I needed that.

To within a few (10?) percent, 1kJ = 1BTU.
So, 1KJ/kg ~= 1BTU/2.2lb

Enthalpy of vaporization (water) is 2257 kJ/kg
so ~1000BTU/lb

On 10/10/2015 8:45 PM, Muggles wrote:

We had a solar water heater for our above ground pool, but it didn't
work that well when the temps got cooler at night. Maybe you're talking
about something different than what we had for our pool.

ISTM that you're looking for ways to *retain* heat moreso than
*gain* heat. Your solar pool heater suffered from heat *loss*
(evaporative and radiated to the blackness of space). An insulated
pool *cover* would have benefitted you for the overnite hours.

I.e., you want to keep things at a relatively constant temperature
despite large (?) variations in the surrounding *air*.

You wouldn't, for example, want to heat the water to ~130F during
the daytime lest you kill the fishies and plants (?)

So, you want to put lots of energy into something that will store
it and slowly re-radiate it when needed. Water and earth are
two good candidates: water can be moved relatively easily
(so you can bring heat from point A to point B); earth is
cheap to amass.

I still think a ground sourced heat pump of some sort. Though not
necessarily a COTS solution as your plants don't need HEPA filtration,
heat exchangers to isolate the "outdoor" air, etc.

On 10/10/2015 8:55 PM, Muggles wrote:
On 10/10/2015 7:07 PM, mike wrote:
On 10/10/2015 9:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or heard of
them
before. How efficient are they? I'm looking for any idea that might
work.

Eventually, we're installing some solar panels to run anything we might
need in the green house, but right now it's all on the grid to the more
efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

I don't know anything about farming fish, but don't you need
some water/air exchange to keep the oxygen level tolerable to the fish.
If you just block the surface, what keeps the fish alive?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!



We have air bubblers in the tanks. They work even if the tanks are
covered.

So, where do the bubbles go?
Wherever that is is where the evaporation goes.
The bubbles assist evaporation. The air flow also carries away
the heat you're trying to contain.
Best way is to use thick insulation and seal the area between
the water and the insulation. But you can't have bubbles if you
do that.
You have to do the thermodynamics math for the whole system.
It's very easy to spend a lot of money optimizing one thing, then
ruin that optimization by some other optimization decision.

The bottom line is that you have losses from the system to the
environment. You keep the temperature stable by adding
heat equal to those losses. If you do that, what goes on inside
the system is largely irrelevant when it comes to operating costs.

Anything solar only works during the day. But your greatest need
is at night. Managing that requires the same amount of heat, but
you need to store it at a higher temperature during the day
and release it at night. That means you can't use the huge amount
of water in the fish tank as the thermal mass...unless you like
your fish well done.

On Saturday, October 10, 2015 at 2:12:42 PM UTC-4, Muggles wrote:
On 10/10/2015 11:42 AM, Stormin Mormon wrote:
On 10/9/2015 12:26 PM, Muggles wrote:

We're re-building our hoop green house and using wood this time. We
have a aquaponics system where we raise fish, pump the fish water into
grow beds so the plants and plant media can filter the water, pump that
water into a sump and then that water goes to a large rock and sand
filter before it's pumped back into the fish tanks.

We're looking for a way to keep the water in the tanks warm in the
winter without it costing us an arm and a leg to heat the green house
itself. We're going to have about 800 to 1000 gallons of water in the
green house tanks, plus have passive solar heat from the ground that'll
have a thick layer of gravel in addition to having windows at the proper
angle to capture the winter sunlight and heat. We'll also have vents and
windows we can open at the peak of the green house to vent moisture and
too much hot air when needed on warmer days.

The problem is that if we heat the greenhouse along with using water
tank heaters the temps can drop dramatically in the greenhouse and
plants and fish don't do well if the temps are too drastic at night, so
I was thinking of using heat cables/tapes around the pvc pipes that
connect all the water flowing from tanks to plants to sump to filter vs.
using in tank water heaters.

We're also hoping for a solution that'll cost less to power and at the
same time keep the temps more stable in the green house. All the walls
and roofs are being insulated, too.

Does anyone know if heating tapes would work for this or not?


Doubt it. The common heat tapes are designed to keep water
(barely) over the freezing temp. I'd expect them to work
well below the 60F you want.

With this much water, I'd check with pet stores and see
what they think. Propane is usually cheaper than electric
as a fuel source.

Perhaps a propane residential water heater, and tempering
valve?

Would a water heater like that end up costing more in powering it?
--
Maggie


Round in circles we go, with no definition of the actual problem.
Cost more in power than what?

On Saturday, October 10, 2015 at 11:52:12 PM UTC-4, Muggles wrote:
On 10/10/2015 4:21 PM, Tekkie® wrote:
Muggles posted for all of us...



We're re-building our hoop green house and using wood this time. We
have a aquaponics system where we raise fish, pump the fish water into
grow beds so the plants and plant media can filter the water, pump that
water into a sump and then that water goes to a large rock and sand
filter before it's pumped back into the fish tanks.

We're looking for a way to keep the water in the tanks warm in the
winter without it costing us an arm and a leg to heat the green house
itself. We're going to have about 800 to 1000 gallons of water in the
green house tanks, plus have passive solar heat from the ground that'll
have a thick layer of gravel in addition to having windows at the proper
angle to capture the winter sunlight and heat. We'll also have vents and
windows we can open at the peak of the green house to vent moisture and
too much hot air when needed on warmer days.

The problem is that if we heat the greenhouse along with using water
tank heaters the temps can drop dramatically in the greenhouse and
plants and fish don't do well if the temps are too drastic at night, so
I was thinking of using heat cables/tapes around the pvc pipes that
connect all the water flowing from tanks to plants to sump to filter vs.
using in tank water heaters.

We're also hoping for a solution that'll cost less to power and at the
same time keep the temps more stable in the green house. All the walls
and roofs are being insulated, too.

Does anyone know if heating tapes would work for this or not?

I don't think the pvc pipe would be a good conductor of the heat given off
by the tape. Perhaps heater in the fish tank would be best.


Right now we have some large aquarium heaters, but they use a lot of
electricity.

--
Maggie

Any electric heating element is 100% efficient in producing heat.
If that aquarium heater is producing X heat for Y KWH, any
other electric heating element you replace it with, if it produces
5X heat is going to take 5Y KWH.

On 10/10/2015 11:52 PM, Muggles wrote:

Does anyone know if heating tapes would work for this or not?

I don't think the pvc pipe would be a good conductor of the heat given off
by the tape. Perhaps heater in the fish tank would be best.


Right now we have some large aquarium heaters, but they use a lot of
electricity.


How many separate tanks do you have?

If you can find someone who's good with hot water heat
(hydrionic systems) there is a good chance you can rig
some thing using separate thermostats and separate
zone valves. I'm thinking of a water heater set way
down low, and some kind of cirulating pump. The pump
will feed in warm water if the individual tank gets
too cold. Much like heating a house with zones, when
individual room gets too cold.

-
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On 10/11/2015 7:36 AM, trader_4 wrote:
On Saturday, October 10, 2015 at 2:12:42 PM UTC-4, Muggles wrote:

Would a water heater like that end up costing more in powering it?
--
Maggie


Round in circles we go, with no definition of the actual problem.
Cost more in power than what?


But, dear, you NEVER tell me ANYTHING!

-
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On Fri, 09 Oct 2015 11:26:04 -0500, Muggles wrote:


We're re-building our hoop green house and using wood this time. We
have a aquaponics system where we raise fish, pump the fish water into
grow beds so the plants and plant media can filter the water, pump that
water into a sump and then that water goes to a large rock and sand
filter before it's pumped back into the fish tanks.

We're looking for a way to keep the water in the tanks warm in the
winter without it costing us an arm and a leg to heat the green house
itself. We're going to have about 800 to 1000 gallons of water in the
green house tanks, plus have passive solar heat from the ground that'll
have a thick layer of gravel in addition to having windows at the proper
angle to capture the winter sunlight and heat. We'll also have vents and
windows we can open at the peak of the green house to vent moisture and
too much hot air when needed on warmer days.

Do you have room for more tanks? I'm thinking of a thousand gallon
livestock tank. Insulate it as much as practical. Heat it with all the
solar
tricks, then slowly release the water into your system as needed.
Some examples here http://alturl.com/c6ino I don't know a thing about
this particular company. I just picked one after a search.



--
Using Opera's mail client: http://www.opera.com/mail/

On 10/11/2015 7:40 AM, trader_4 wrote:
On Saturday, October 10, 2015 at 11:52:12 PM UTC-4, Muggles wrote:
On 10/10/2015 4:21 PM, Tekkie® wrote:
I don't think the pvc pipe would be a good conductor of the heat given off
by the tape. Perhaps heater in the fish tank would be best.


Right now we have some large aquarium heaters, but they use a lot of
electricity.

--
Maggie

Any electric heating element is 100% efficient in producing heat.
If that aquarium heater is producing X heat for Y KWH, any
other electric heating element you replace it with, if it produces
5X heat is going to take 5Y KWH.


As my old college prof said, they are 100%
because there is no heat lost up the
chimney. That said, electric is epensive in
most areas.

The propane heater and circulating pumps will
cost more to set up, but should save money
later in terms of operating costs.

-
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On Fri, 9 Oct 2015 09:35:17 -0700 (PDT), trader_4
wrote:

From the description, very unclear what the objectives and requirements
really are.

Maybe this is what she is trying to do?

https://www.youtube.com/watch?v=9qZPwBPAqks

She could contact: (for heating solutions)...I guess

www.growingpower.org

www.seagrant.wisc.edu

Muggles wrote:
On 10/10/2015 2:02 PM, Bob F wrote:
Muggles wrote:
On 10/10/2015 11:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or heard
of them before. How efficient are they? I'm looking for any idea
that might work.

Eventually, we're installing some solar panels to run anything we
might need in the green house, but right now it's all on the grid
to the more efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!


As it evaporates, does it not warm the surrounding air?

Sure! That's how evaporative coolers work. ;-)



mmmmm If the air is 50° and the water is 70° and some warmer water
evaporates, the evaporation would be cooler than the 70°, but still
warmer than the 50°, right?

The air will be cooler and more humid than previosly. In dry climates,
evaporative coolers really do cool. The water cools as it evaporates, and the
resulting cooler vapor cools the air.

https://www.google.com/search?q=how+...utf-8&oe=utf-8

Muggles wrote:
On 10/10/2015 3:43 PM, Stormin Mormon wrote:
On 10/10/2015 2:12 PM, Muggles wrote:
Does anyone know if heating tapes would work for this or not?


Doubt it. The common heat tapes are designed to keep water
(barely) over the freezing temp. I'd expect them to work
well below the 60F you want.

With this much water, I'd check with pet stores and see
what they think. Propane is usually cheaper than electric
as a fuel source.

Perhaps a propane residential water heater, and tempering
valve?

Would a water heater like that end up costing more in powering it?


My experience with heat, is that propane is
cheaper than electric. In any, or, whatever
form.


ok thanks for the info.

That will depend completely on the relative costs of propane and electricity
where you live.

"
a.. Multiply the oil heat price per gallon by 0.663 to give the equivalent price
per gallon of propane
a.. Multiply the natural gas delivered price per therm by 0.92 to give the
equivalent price per gallon of propane
a.. Multiply the electricity price per kWh by 27.0 to give the equivalent price
per gallon of propane "
from http://www.thefrugallife.com/heating.html

On 10/10/2015 11:16 PM, Don Y wrote:
On 10/10/2015 8:45 PM, Muggles wrote:

We had a solar water heater for our above ground pool, but it didn't
work that well when the temps got cooler at night. Maybe you're talking
about something different than what we had for our pool.

ISTM that you're looking for ways to *retain* heat moreso than
*gain* heat. Your solar pool heater suffered from heat *loss*
(evaporative and radiated to the blackness of space). An insulated
pool *cover* would have benefitted you for the overnite hours.

I.e., you want to keep things at a relatively constant temperature
despite large (?) variations in the surrounding *air*.

You wouldn't, for example, want to heat the water to ~130F during
the daytime lest you kill the fishies and plants (?)

So, you want to put lots of energy into something that will store
it and slowly re-radiate it when needed. Water and earth are
two good candidates: water can be moved relatively easily
(so you can bring heat from point A to point B); earth is
cheap to amass.

I still think a ground sourced heat pump of some sort. Though not
necessarily a COTS solution as your plants don't need HEPA filtration,
heat exchangers to isolate the "outdoor" air, etc.

hmm We have to be careful with anything that has access to the water,
and that includes not adding any chemicals or metals to the water, too.
Would a heat pump leach out any metals into the water?

--
Maggie

On 10/10/2015 11:30 PM, mike wrote:
On 10/10/2015 8:55 PM, Muggles wrote:
On 10/10/2015 7:07 PM, mike wrote:
On 10/10/2015 9:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or heard of
them
before. How efficient are they? I'm looking for any idea that might
work.

Eventually, we're installing some solar panels to run anything we
might
need in the green house, but right now it's all on the grid to the
more
efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

I don't know anything about farming fish, but don't you need
some water/air exchange to keep the oxygen level tolerable to the fish.
If you just block the surface, what keeps the fish alive?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!



We have air bubblers in the tanks. They work even if the tanks are
covered.

So, where do the bubbles go?
Wherever that is is where the evaporation goes.
The bubbles assist evaporation. The air flow also carries away
the heat you're trying to contain.
Best way is to use thick insulation and seal the area between
the water and the insulation. But you can't have bubbles if you
do that.
You have to do the thermodynamics math for the whole system.
It's very easy to spend a lot of money optimizing one thing, then
ruin that optimization by some other optimization decision.

The bottom line is that you have losses from the system to the
environment. You keep the temperature stable by adding
heat equal to those losses. If you do that, what goes on inside
the system is largely irrelevant when it comes to operating costs.

Anything solar only works during the day. But your greatest need
is at night. Managing that requires the same amount of heat, but
you need to store it at a higher temperature during the day
and release it at night. That means you can't use the huge amount
of water in the fish tank as the thermal mass...unless you like
your fish well done.

Do you think the water would hold temps better if the pumps were turned
off at night? The bubblers have to stay on to oxygenate the water, though.

--
Maggie

On 10/11/2015 7:51 PM, Muggles wrote:

I still think a ground sourced heat pump of some sort. Though not
necessarily a COTS solution as your plants don't need HEPA filtration,
heat exchangers to isolate the "outdoor" air, etc.

hmm We have to be careful with anything that has access to the water,
and that includes not adding any chemicals or metals to the water, too.
Would a heat pump leach out any metals into the water?

Sorry, I wasn't thinking in terms of heating the *water*, etc.

Rather, I was thinking that the building was (relatively) sealed.
At one end of the building, you blow air *into* a pipe (duct)
that runs underground (for some distance). At the other end
of the pipe, the air comes back out *into* the building.

I.e., you are just circulating the air "through" the ground
to steal the warmth of the soil to bring the air back to that
nominal temperature (this assumes soil temperature is "OK"
as a target temperature).

Imagine a concrete pipe snaking around under the soil so the
pipe itself is always at "soil temperature" -- lots of mass.
Then, moving air (slow enough that it can absorb that heat)
through that pipe and back out into the building.

You could fashion such a pipe from cinderblocks stacked
with their voids aligned to make a "dual pipe". You don't
really care about isolating the air that flows through this pipe
from the air *in* the building (if you were using this for a
living space, you'd NOT want the air to circulate in your home!)

[Note that you need to know what sorts of pathogens might be
present in your soil before such an undertaking]

You could do something similar with water in pipes but then
you'd need a heat exchanger to harvest the heat from the
circulating water, etc.

On 10/11/2015 6:49 AM, Stormin Mormon wrote:
On 10/10/2015 11:52 PM, Muggles wrote:

Does anyone know if heating tapes would work for this or not?

I don't think the pvc pipe would be a good conductor of the heat
given off
by the tape. Perhaps heater in the fish tank would be best.


Right now we have some large aquarium heaters, but they use a lot of
electricity.


How many separate tanks do you have?

Right now we have one 900 gallon tank for big adult fish, a 250 gallon
tank for juveniles, and a 100 gallon tank for babies.

If you can find someone who's good with hot water heat
(hydrionic systems) there is a good chance you can rig
some thing using separate thermostats and separate
zone valves. I'm thinking of a water heater set way
down low, and some kind of cirulating pump. The pump
will feed in warm water if the individual tank gets
too cold. Much like heating a house with zones, when
individual room gets too cold.


hmmm That sound interesting. When we get the green house finished
we're going to leave the big 900 gallon tank outside (emptied) and put
in 200 gallon tanks in 2 rows of 4 each, I think. The grow beds will
bed above the tanks.


--
Maggie

On 10/11/2015 7:43 AM, Dean Hoffman wrote:
On Fri, 09 Oct 2015 11:26:04 -0500, Muggles wrote:


We're re-building our hoop green house and using wood this time. We
have a aquaponics system where we raise fish, pump the fish water into
grow beds so the plants and plant media can filter the water, pump that
water into a sump and then that water goes to a large rock and sand
filter before it's pumped back into the fish tanks.

We're looking for a way to keep the water in the tanks warm in the
winter without it costing us an arm and a leg to heat the green house
itself. We're going to have about 800 to 1000 gallons of water in the
green house tanks, plus have passive solar heat from the ground that'll
have a thick layer of gravel in addition to having windows at the proper
angle to capture the winter sunlight and heat. We'll also have vents and
windows we can open at the peak of the green house to vent moisture and
too much hot air when needed on warmer days.

Do you have room for more tanks? I'm thinking of a thousand gallon
livestock tank. Insulate it as much as practical. Heat it with all the
solar
tricks, then slowly release the water into your system as needed.
Some examples here http://alturl.com/c6ino I don't know a thing about
this particular company. I just picked one after a search.




Those are similar to a couple of the tanks we have now. We're
insulating the green house pretty heavily, so we haven't gotten to the
part where we move everything in doors, yet. The clocks ticking tho.

--
Maggie

Muggles wrote:
On 10/10/2015 11:30 PM, mike wrote:
On 10/10/2015 8:55 PM, Muggles wrote:
On 10/10/2015 7:07 PM, mike wrote:
On 10/10/2015 9:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or
heard of them
before. How efficient are they? I'm looking for any idea that
might work.

Eventually, we're installing some solar panels to run anything
we might
need in the green house, but right now it's all on the grid to
the more
efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

I don't know anything about farming fish, but don't you need
some water/air exchange to keep the oxygen level tolerable to the
fish. If you just block the surface, what keeps the fish alive?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!



We have air bubblers in the tanks. They work even if the tanks are
covered.

So, where do the bubbles go?
Wherever that is is where the evaporation goes.
The bubbles assist evaporation. The air flow also carries away
the heat you're trying to contain.
Best way is to use thick insulation and seal the area between
the water and the insulation. But you can't have bubbles if you
do that.
You have to do the thermodynamics math for the whole system.
It's very easy to spend a lot of money optimizing one thing, then
ruin that optimization by some other optimization decision.

The bottom line is that you have losses from the system to the
environment. You keep the temperature stable by adding
heat equal to those losses. If you do that, what goes on inside
the system is largely irrelevant when it comes to operating costs.

Anything solar only works during the day. But your greatest need
is at night. Managing that requires the same amount of heat, but
you need to store it at a higher temperature during the day
and release it at night. That means you can't use the huge amount
of water in the fish tank as the thermal mass...unless you like
your fish well done.

Do you think the water would hold temps better if the pumps were
turned off at night? The bubblers have to stay on to oxygenate the
water, though.

Yes, turning off the pumps will eliminate heat loss from the pipes after they
cool off. But in freezing weather, pipe damage risk increases.

On 10/11/2015 9:00 PM, Bob F wrote:
Muggles wrote:
On 10/10/2015 11:30 PM, mike wrote:
On 10/10/2015 8:55 PM, Muggles wrote:
On 10/10/2015 7:07 PM, mike wrote:
On 10/10/2015 9:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or
heard of them
before. How efficient are they? I'm looking for any idea that
might work.

Eventually, we're installing some solar panels to run anything
we might
need in the green house, but right now it's all on the grid to
the more
efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

I don't know anything about farming fish, but don't you need
some water/air exchange to keep the oxygen level tolerable to the
fish. If you just block the surface, what keeps the fish alive?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!



We have air bubblers in the tanks. They work even if the tanks are
covered.

So, where do the bubbles go?
Wherever that is is where the evaporation goes.
The bubbles assist evaporation. The air flow also carries away
the heat you're trying to contain.
Best way is to use thick insulation and seal the area between
the water and the insulation. But you can't have bubbles if you
do that.
You have to do the thermodynamics math for the whole system.
It's very easy to spend a lot of money optimizing one thing, then
ruin that optimization by some other optimization decision.

The bottom line is that you have losses from the system to the
environment. You keep the temperature stable by adding
heat equal to those losses. If you do that, what goes on inside
the system is largely irrelevant when it comes to operating costs.

Anything solar only works during the day. But your greatest need
is at night. Managing that requires the same amount of heat, but
you need to store it at a higher temperature during the day
and release it at night. That means you can't use the huge amount
of water in the fish tank as the thermal mass...unless you like
your fish well done.

Do you think the water would hold temps better if the pumps were
turned off at night? The bubblers have to stay on to oxygenate the
water, though.

Yes, turning off the pumps will eliminate heat loss from the pipes after they
cool off. But in freezing weather, pipe damage risk increases.


Suggestions...
Change the subject line to better describe what this thread has turned into.
Describe better what you're doing with the fish and what you're growing.

Once the fish leave your premises, all manner of liability issues arise.
Food laws and regulations are not always intuitive.

Grow something with high profit margin, like weed.
That significantly lessens your need to minimize heat loss.
Consume some of the product and you'll be significantly less
motivated to fix anything. ;-)

DO THE MATH. Find out where the heat is going. Fix the biggest issues.
There's no need to optimize the small stuff if you've ignored the low
hanging fruit.

Right now, you're getting random inputs from people who have to make
assumptions and guesses about what you're doing. Throw some pictures
on a sharing site.

I find the project fascinating, but I have nothing better to do ;-)

On 10/11/2015 11:44 AM, Bob F wrote:
Muggles wrote:
On 10/10/2015 2:02 PM, Bob F wrote:
Muggles wrote:
On 10/10/2015 11:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or heard
of them before. How efficient are they? I'm looking for any idea
that might work.

Eventually, we're installing some solar panels to run anything we
might need in the green house, but right now it's all on the grid
to the more efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!


As it evaporates, does it not warm the surrounding air?

Sure! That's how evaporative coolers work. ;-)



mmmmm If the air is 50° and the water is 70° and some warmer water
evaporates, the evaporation would be cooler than the 70°, but still
warmer than the 50°, right?

The air will be cooler and more humid than previosly. In dry climates,
evaporative coolers really do cool. The water cools as it evaporates, and the
resulting cooler vapor cools the air.

https://www.google.com/search?q=how+...utf-8&oe=utf-8

So, the evaporating air might cool down to from 70 to 60 as it
evaporates, but then warm the air from 50 to 60?


--
Maggie

Muggles wrote:
On 10/11/2015 11:44 AM, Bob F wrote:
Muggles wrote:
On 10/10/2015 2:02 PM, Bob F wrote:
Muggles wrote:
On 10/10/2015 11:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or
heard of them before. How efficient are they? I'm looking for
any idea that might work.

Eventually, we're installing some solar panels to run anything
we might need in the green house, but right now it's all on
the grid to the more efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!


As it evaporates, does it not warm the surrounding air?

Sure! That's how evaporative coolers work. ;-)



mmmmm If the air is 50° and the water is 70° and some warmer water
evaporates, the evaporation would be cooler than the 70°, but still
warmer than the 50°, right?

The air will be cooler and more humid than previosly. In dry
climates, evaporative coolers really do cool. The water cools as it
evaporates, and the resulting cooler vapor cools the air.

https://www.google.com/search?q=how+...utf-8&oe=utf-8

So, the evaporating air might cool down to from 70 to 60 as it
evaporates, but then warm the air from 50 to 60?

NO

The water evaporates, thereby cooling the air.

Notice the smilie at the end of
"Sure! That's how evaporative coolers work. ;-)"

That means I was kidding.

On 10/11/2015 10:13 PM, Don Y wrote:
On 10/11/2015 7:51 PM, Muggles wrote:

I still think a ground sourced heat pump of some sort. Though not
necessarily a COTS solution as your plants don't need HEPA filtration,
heat exchangers to isolate the "outdoor" air, etc.

hmm We have to be careful with anything that has access to the water,
and that includes not adding any chemicals or metals to the water, too.
Would a heat pump leach out any metals into the water?

Sorry, I wasn't thinking in terms of heating the *water*, etc.

Rather, I was thinking that the building was (relatively) sealed.
At one end of the building, you blow air *into* a pipe (duct)
that runs underground (for some distance). At the other end
of the pipe, the air comes back out *into* the building.

I.e., you are just circulating the air "through" the ground
to steal the warmth of the soil to bring the air back to that
nominal temperature (this assumes soil temperature is "OK"
as a target temperature).

Imagine a concrete pipe snaking around under the soil so the
pipe itself is always at "soil temperature" -- lots of mass.
Then, moving air (slow enough that it can absorb that heat)
through that pipe and back out into the building.

You could fashion such a pipe from cinderblocks stacked
with their voids aligned to make a "dual pipe". You don't
really care about isolating the air that flows through this pipe
from the air *in* the building (if you were using this for a
living space, you'd NOT want the air to circulate in your home!)

[Note that you need to know what sorts of pathogens might be
present in your soil before such an undertaking]

You could do something similar with water in pipes but then
you'd need a heat exchanger to harvest the heat from the
circulating water, etc.

hmmm We don't have the space to do any more digging to bury stuff, but
we do have the metal circulation vent buried for the stove.

--
Maggie

On 10/11/2015 11:00 PM, Bob F wrote:
Muggles wrote:
On 10/10/2015 11:30 PM, mike wrote:
On 10/10/2015 8:55 PM, Muggles wrote:
On 10/10/2015 7:07 PM, mike wrote:
On 10/10/2015 9:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or
heard of them
before. How efficient are they? I'm looking for any idea that
might work.

Eventually, we're installing some solar panels to run anything
we might
need in the green house, but right now it's all on the grid to
the more
efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

I don't know anything about farming fish, but don't you need
some water/air exchange to keep the oxygen level tolerable to the
fish. If you just block the surface, what keeps the fish alive?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!



We have air bubblers in the tanks. They work even if the tanks are
covered.

So, where do the bubbles go?
Wherever that is is where the evaporation goes.
The bubbles assist evaporation. The air flow also carries away
the heat you're trying to contain.
Best way is to use thick insulation and seal the area between
the water and the insulation. But you can't have bubbles if you
do that.
You have to do the thermodynamics math for the whole system.
It's very easy to spend a lot of money optimizing one thing, then
ruin that optimization by some other optimization decision.

The bottom line is that you have losses from the system to the
environment. You keep the temperature stable by adding
heat equal to those losses. If you do that, what goes on inside
the system is largely irrelevant when it comes to operating costs.

Anything solar only works during the day. But your greatest need
is at night. Managing that requires the same amount of heat, but
you need to store it at a higher temperature during the day
and release it at night. That means you can't use the huge amount
of water in the fish tank as the thermal mass...unless you like
your fish well done.

Do you think the water would hold temps better if the pumps were
turned off at night? The bubblers have to stay on to oxygenate the
water, though.

Yes, turning off the pumps will eliminate heat loss from the pipes after they
cool off. But in freezing weather, pipe damage risk increases.



Well, all the pipes for the green house will be physically in the green
house and it's going to be insulated better than our house!

--
Maggie

On 10/12/2015 3:48 AM, mike wrote:

Suggestions...
Change the subject line to better describe what this thread has turned
into.
Describe better what you're doing with the fish and what you're growing.

We work towards having an urban farm, so one of the things we're doing
is raising our own fish to consume.

Once the fish leave your premises, all manner of liability issues arise.
Food laws and regulations are not always intuitive.

We can't sell the fish dressed out, but we can sell them live. IOW,
someone can come and bring a bucket, dip out their fish, and take it
home and dress it out themselves. The fish is part of an aquaponics set
up. We pump the fish water into grow beds which help consume and filter
out the fish waste. That water is sent to a sump tank with small baby
fish in it and waste eating critters like crawdads and catfish. Then
that water is sent through a large barrel filter, and then drains back
into the main fish tank. The initial system we set up was small, but it
has grown as the fish grew to adulthood. Now, we have large tilapia and
our son is planning a fall fish fry for him and his buddies. Each adult
fish is at least 9 pounds +/- undressed.

Grow something with high profit margin, like weed.
That significantly lessens your need to minimize heat loss.
Consume some of the product and you'll be significantly less
motivated to fix anything. ;-)

When we get the new green house finished, we're hoping to grow fresh
food we can consume ourselves in the winter time. Eventually, we'll
tweak it to possibly sell crops like lettuce.

DO THE MATH. Find out where the heat is going. Fix the biggest issues.
There's no need to optimize the small stuff if you've ignored the low
hanging fruit.

The biggest issue is heating in the winter time, and venting extra day
time heat while at the same time having passive heat sources to keep it
warm at night.

Right now, you're getting random inputs from people who have to make
assumptions and guesses about what you're doing. Throw some pictures
on a sharing site.

I'll have to take some new photos. Everything I've taken thus far is of
the old set-up. We moved the big fish to a 900 gallon tank that's been
outside of the green house for spring-summer-fall. We'll break down that
tank and move them inside when the night temps get too cold. I may just
take a short video with my phone and upload that.

I find the project fascinating, but I have nothing better to do ;-)

It's a hobby, so far, anyway!

--
Maggie

On 10/13/2015 7:55 PM, Bob F wrote:
Muggles wrote:
On 10/11/2015 11:44 AM, Bob F wrote:
Muggles wrote:
On 10/10/2015 2:02 PM, Bob F wrote:
Muggles wrote:
On 10/10/2015 11:48 AM, Don Y wrote:
On 10/10/2015 5:40 AM, Stormin Mormon wrote:
On 10/9/2015 4:44 PM, Muggles wrote:
Roof de-icing cables? hmmm I've never worked with those or
heard of them before. How efficient are they? I'm looking for
any idea that might work.

Eventually, we're installing some solar panels to run anything
we might need in the green house, but right now it's all on
the grid to the more efficient the heat source the better.

Pretty much all electric heaters are the same
efficiency. 5,200 BTU per hour with 1500 watt
consumption.

From what I can see here, the big problem is
heat loss over night. Consider focuss your
efforts there. Vapor barrier to slow evaporation?

It takes 1 BTU to heat a pound of water 1 degree. Let that
pound of water *evaporate* and you've LOST ~1000BTU's!


As it evaporates, does it not warm the surrounding air?

Sure! That's how evaporative coolers work. ;-)



mmmmm If the air is 50° and the water is 70° and some warmer water
evaporates, the evaporation would be cooler than the 70°, but still
warmer than the 50°, right?

The air will be cooler and more humid than previosly. In dry
climates, evaporative coolers really do cool. The water cools as it
evaporates, and the resulting cooler vapor cools the air.

https://www.google.com/search?q=how+...utf-8&oe=utf-8

So, the evaporating air might cool down to from 70 to 60 as it
evaporates, but then warm the air from 50 to 60?

NO

The water evaporates, thereby cooling the air.

Notice the smilie at the end of
"Sure! That's how evaporative coolers work. ;-)"

That means I was kidding.





gotcha!

--
Maggie

On Wed, 14 Oct 2015 12:07:22 -0500, Muggles wrote:

hmmm We don't have the space to do any more digging to bury stuff, but
we do have the metal circulation vent buried for the stove.

Have you looked into an outdoor patio heater for the green house,
placed next to the fish pond?

http://www.amazon.com/s?ie=UTF8&page=1&rh=i%3Aaps%2Ck%3Apropane%20patio% 20heater

On 10/14/2015 12:32 PM, Oren wrote:
On Wed, 14 Oct 2015 12:07:22 -0500, Muggles wrote:

hmmm We don't have the space to do any more digging to bury stuff, but
we do have the metal circulation vent buried for the stove.

Have you looked into an outdoor patio heater for the green house,
placed next to the fish pond?

http://www.amazon.com/s?ie=UTF8&page=1&rh=i%3Aaps%2Ck%3Apropane%20patio% 20heater


We've seen some of those locally, and have been thinking about it.
We've got a couple of smaller propane heaters that may also work in this
new green house, but the ones like in your link are on a short list of
possibles in the future.

--
Maggie

On Thu, 15 Oct 2015 00:28:16 -0500, Muggles wrote:

I've given pllllenty of details. Maybe you're just not paying attention?

You never stated what kind of fish, their tolerance for cold water,
your climate, right?

On 10/15/2015 9:22 AM, Oren wrote:
On Thu, 15 Oct 2015 00:28:16 -0500, Muggles wrote:

I've given pllllenty of details. Maybe you're just not paying attention?

You never stated what kind of fish, their tolerance for cold water,
your climate, right?


Nobody asked, but I did mention tilapia and water temps.

--
Maggie

Uncle Monster posted for all of us...


Why heck Muggs Baby, I wish I could work on stuff like that. I did put my braces on both knees yesterday and get in my walker and make about a 100 foot trip to the nurses station and back. It wore me out and it was the first time I'd done that in months but I'm trying again today. It's amazing how well hinged knee braces can stabilize loose, flopping knees. I can't wait to start break dancing again. ^_^

[8~{} Uncle Dancing Monster


Cue up Night Fever

--
Tekkie

On Thursday, October 15, 2015 at 4:13:06 PM UTC-5, Tekkie® wrote:
Uncle Monster posted for all of us...


Why heck Muggs Baby, I wish I could work on stuff like that. I did put my braces on both knees yesterday and get in my walker and make about a 100 foot trip to the nurses station and back. It wore me out and it was the first time I'd done that in months but I'm trying again today. It's amazing how well hinged knee braces can stabilize loose, flopping knees. I can't wait to start break dancing again. ^_^

[8~{} Uncle Dancing Monster


Cue up Night Fever
--
Tekkie

Isn't that a Bee Gees disco song? o_O

[8~{} Uncle Dancing Monster

Uncle Monster posted for all of us...



On Thursday, October 15, 2015 at 4:13:06 PM UTC-5, Tekkie® wrote:
Uncle Monster posted for all of us...


Why heck Muggs Baby, I wish I could work on stuff like that. I did put my braces on both knees yesterday and get in my walker and make about a 100 foot trip to the nurses station and back. It wore me out and it was the first time I'd done that in months but I'm trying again today. It's amazing how well hinged knee braces can stabilize loose, flopping knees. I can't wait to start break dancing again. ^_^

[8~{} Uncle Dancing Monster


Cue up Night Fever
--
Tekkie

Isn't that a Bee Gees disco song? o_O

[8~{} Uncle Dancing Monster

Yup, you're are moving up!

--
Tekkie

On 10/15/2015 3:04 PM, Uncle Monster wrote:
On Thursday, October 15, 2015 at 1:48:36 PM UTC-5, Muggles wrote:
On 10/15/2015 1:41 PM, Uncle Monster wrote:
On Thursday, October 15, 2015 at 12:20:27 PM UTC-5, Muggles wrote:
On 10/15/2015 11:31 AM, Uncle Monster wrote:
On Thursday, October 15, 2015 at 10:56:43 AM UTC-5, Muggles wrote:
On 10/15/2015 10:24 AM, Uncle Monster wrote:
On Thursday, October 15, 2015 at 9:59:18 AM UTC-5, Muggles wrote:
On 10/15/2015 9:53 AM, trader_4 wrote:
On Thursday, October 15, 2015 at 10:40:19 AM UTC-4, Muggles wrote:
On 10/15/2015 7:32 AM, trader_4 wrote:
On Thursday, October 15, 2015 at 1:28:11 AM UTC-4, Muggles wrote:
On 10/14/2015 7:27 PM, trader_4 wrote:
On Wednesday, October 14, 2015 at 8:19:08 PM UTC-4, mike wrote:
On 10/14/2015 4:17 PM, tony944 wrote:


You're a good man, Monster.
--
Maggie

I'm not a good man, I'm an exceptional monster. ^_^

[8~{} Uncle Original Monster


I'd sure appreciate if the exceptonal two of you
would trim excess text.

-
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..

On Saturday, October 17, 2015 at 7:32:06 AM UTC-5, Stormin Mormon wrote:
On 10/15/2015 3:04 PM, Uncle Monster wrote:

I'd sure appreciate if the exceptonal two of you
would trim excess text.
-
.
Is that better. I usually don't think of it because I don't have a problem with line wrap but I've been inconsiderate of those who's newsreaders don't wrap very well. I must pay attention in the future. o_O

White men caynt wrap, ^__^

[8~{} Uncle Wrapping Monster