I keep seeing homes for sale with heat pumps. It's been a while, but I
have seen -25F in winter, so I am puzzled why folks use heat pumps here.
Had a h.p. in Florida, and when the temp got down to the forties, it
wasn't warm enough indoors with the h.p. Is there new technology?

On Sep 15, 8:25*am, Norminn wrote:
I keep seeing homes for sale with heat pumps. *It's been a while, but I
have seen -25F in winter, so I am puzzled why folks use heat pumps here.
* Had a h.p. in Florida, and when the temp got down to the forties, it
wasn't warm enough indoors with the h.p. *Is there new technology?

Are those heat pumps air-based or geothermal? Efficiency
has increased over the years and air based ones can be
efficient sources of heat even down to 20F or so. But if
you see -25F in winter, unless it's geothermal, or dual fuel,
forget it. Here in NJ, where temps only reach the single
digits rarely, teens sometimes, I don;t know of anyone that
has an air-based heat pump.

Norminn wrote:

I keep seeing homes for sale with heat pumps. It's been a while, but I
have seen -25F in winter, so I am puzzled why folks use heat pumps here.
Had a h.p. in Florida, and when the temp got down to the forties, it
wasn't warm enough indoors with the h.p. Is there new technology?

Ground source heat pumps work fine in colder climates.

On 9/15/2012 8:39 AM, wrote:
On Sep 15, 8:25 am, Norminn wrote:
I keep seeing homes for sale with heat pumps. It's been a while, but I
have seen -25F in winter, so I am puzzled why folks use heat pumps here.
Had a h.p. in Florida, and when the temp got down to the forties, it
wasn't warm enough indoors with the h.p. Is there new technology?

Are those heat pumps air-based or geothermal? Efficiency
has increased over the years and air based ones can be
efficient sources of heat even down to 20F or so. But if
you see -25F in winter, unless it's geothermal, or dual fuel,
forget it. Here in NJ, where temps only reach the single
digits rarely, teens sometimes, I don;t know of anyone that
has an air-based heat pump.

I have a 3 yo Amana HP with propane backup here in western NC. It was
the most efficient unit at the time. You get very little heat when the
temp is in the mid 30s. It does use the propane during the de-ice
cycles periodically. At about 30, it switches over to 100% propane.
During the winters of 09 and 10, we used lots of propane, probably more
in 10. In 11, we used very little, as it was warmer. I'm sorry we
didn't put in geothermal because there were a lot of tax incentives at
the time, which probably would have made it economical. BTW, I don't
know about all the geothermal units, but my niece has a geothermal unit
and there is nothing visible outside. The heat pump compressor and heat
exchangers are all in the inside unit (Carrier).

On 9/15/2012 8:25 AM, Norminn wrote:
I keep seeing homes for sale with heat pumps. It's been a while, but I
have seen -25F in winter, so I am puzzled why folks use heat pumps here.
Had a h.p. in Florida, and when the temp got down to the forties, it
wasn't warm enough indoors with the h.p. Is there new technology?

I am in PA and friends put in a Mitsubishi split system a few years ago.
My friend is a really sensible guy who is analytical and not a story
teller. They decided to go with the version that also can be used as a
heat pump mainly because it wasn't that much more and for a backup.
They also have an oil fired boiler for hydronic heat.

They used it for the only source of heat the past two winters and the
house was comfortable. We haven't been down to -25F though and I think
the lowest we see here is -10 F in February.

He also ran the numbers and they were able to heat their house for less
than using oil.

On 9/15/2012 7:25 AM, Norminn wrote:
I keep seeing homes for sale with heat pumps. It's been a while, but I
have seen -25F in winter, so I am puzzled why folks use heat pumps here.
Had a h.p. in Florida, and when the temp got down to the forties, it
wasn't warm enough indoors with the h.p. Is there new technology?

Where is here?

More to the point than having once seen it, what are the averages?
Certainly a modern properly sized air-exchange HP will handle into the
lower 30's w/ no problems. The one thing is that they will tend to have
longer recovery time as the exit air temp's will not approach those of
conventional furnace (or even a geothermal unit).

They certainly have improved even air-exchange but in very cold climates
either they use geothermal (ground loop/well/deep reservoir all
possibilities) or have a conventional backup.

We replaced an early air-exchange in E TN w/ geothermal and it was
night/day...this is almost 20 yr ago now and the original HP wasn't but
a cheap contractor-supplied unit in the late 70s when even the good
weren't doing all that well, anyway. But, TVA power was cheap then so
the resistance heaters weren't a big deal--probably 70% of heating in
the area was electric at the time. By the early 90s the HP was on last
legs and power rates were much higher and NG wasn't yet available so
went w/ the higher installation cost of digging the trench and never
regretted it while were still there. AFAIK the system is still
functional w/ no problems--saw the new owner just a couple of years ago
and he's also quite pleased.

It has a thermistor in-line w/ the aux heat that keeps them from being
able to come on above about 18-20F so the 'Emer Heat' logic doesn't try
to kick on if, for example, the house has been turned down and then come
home and reset to normal so the dT is large and it thinks it can't catch
up. Newer t-'stats may also have better logic to know the difference
between chronic failure to keep up and change in demand.

A side benefit of the geothermal was essentially free hot water in
summer using reject heat from the cooling cycle...replacing electric
water heater inputs is _a_good_thing_ (tm) in most places given rates...

--

Norminn wrote:

I keep seeing homes for sale with heat pumps. It's been a while, but I
have seen -25F in winter, so I am puzzled why folks use heat pumps here.
Had a h.p. in Florida, and when the temp got down to the forties, it
wasn't warm enough indoors with the h.p. Is there new technology?

Ground source heat pumps work fine in colder climates.

"George" wrote in message
...
I am in PA and friends put in a Mitsubishi split system a few years ago.
My friend is a really sensible guy who is analytical and not a story
teller. They decided to go with the version that also can be used as a
heat pump mainly because it wasn't that much more and for a backup. They
also have an oil fired boiler for hydronic heat.

They used it for the only source of heat the past two winters and the
house was comfortable. We haven't been down to -25F though and I think the
lowest we see here is -10 F in February.

He also ran the numbers and they were able to heat their house for less
than using oil.

Usually when it gets very cold (say somewhat below 25 deg C) ( I am in the
south so that is very cold to me) the heat pump will turn on the resitive
heating elements if it can not keep up. It may be the heating elements
turned on, but even at that, the electric heat may be cheaper than the price
of oil in an old furnace.

On 9/15/2012 10:16 AM, Ralph Mowery wrote:
"George" wrote in message
...
I am in PA and friends put in a Mitsubishi split system a few years ago.
My friend is a really sensible guy who is analytical and not a story
teller. They decided to go with the version that also can be used as a
heat pump mainly because it wasn't that much more and for a backup. They
also have an oil fired boiler for hydronic heat.

They used it for the only source of heat the past two winters and the
house was comfortable. We haven't been down to -25F though and I think the
lowest we see here is -10 F in February.

He also ran the numbers and they were able to heat their house for less
than using oil.

Usually when it gets very cold (say somewhat below 25 deg C) ( I am in the
south so that is very cold to me) the heat pump will turn on the resitive
heating elements if it can not keep up. It may be the heating elements
turned on, but even at that, the electric heat may be cheaper than the price
of oil in an old furnace.



He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...11-r_pages.pdf


According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

"George" wrote in message
...
He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...11-r_pages.pdf

According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

That sure seems like an impressive unit. I did see what appears to be some
resistive heating elements in the individual units that seem to be an
option.

Being a multizone unit, that should save a lot on the heat cost. I wish my
heat pump was set so I could cut off part of it. I have 2 bed rooms
upstairs that are not used any more and it would be nice to eliminate all
the heat and cooling going to them.
Also a room in the basement has some ducts going to it that would be nice to
completely close off when I wanted to.

On Sep 15, 10:56*am, "Ralph Mowery"
wrote:
"George" wrote in message

...

He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...20brochure%203...

According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

That sure seems like an impressive unit. *I did see what appears to be some
resistive heating elements in the individual units that seem to be an
option.


I think this is just another sales job and you're on to the
truth. It only shows that it has 100% CAPACITY down
to 10F, not how it gets that capacity. Unless the laws of
thermodynamics have been repealed, the efficiency of
ALL heat pumps declines as the outside temp drops.
It's a matter of physics that no manufacturer can avoid.
They can still deliver more heat than a resistive heating
element would at 10F, but the amount of heat you get
out of the heat pump drops on a steady curve as the
temp goes down.

The only way they can get 100% capacity across that
broad temp range is either by:

A - using resistive heat to supplement

B - Downrating the whole thing so that it's rated by what
it produces at 10F.

Option B is nuts for obvious reasons.

On 9/15/2012 11:16 AM, wrote:
On Sep 15, 10:56 am, "Ralph Mowery"
wrote:
"George" wrote in message

...

He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...20brochure%203...

According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

That sure seems like an impressive unit. I did see what appears to be some
resistive heating elements in the individual units that seem to be an
option.


I think this is just another sales job and you're on to the
truth. It only shows that it has 100% CAPACITY down
to 10F, not how it gets that capacity. Unless the laws of
thermodynamics have been repealed, the efficiency of
ALL heat pumps declines as the outside temp drops.
It's a matter of physics that no manufacturer can avoid.
They can still deliver more heat than a resistive heating
element would at 10F, but the amount of heat you get
out of the heat pump drops on a steady curve as the
temp goes down.

The only way they can get 100% capacity across that
broad temp range is either by:

A - using resistive heat to supplement

B - Downrating the whole thing so that it's rated by what
it produces at 10F.

Option B is nuts for obvious reasons.



I think you would want to contact Mitsubishi and explain to them that
the systems they sell can't work as described (hint, Mitsubishi makes
really well engineered stuff and they tend to be really anal about
describing actual performance)

Then you contact my friend and let them know the performance he actually
witnessed isn't possible in his system since it doesn't have resistive
elements.


And maybe you just don't see that everyone who posts in this group isn't
heybub just telling stories to screw with people...

On Sep 15, 1:25*pm, Norminn wrote:
I keep seeing homes for sale with heat pumps. *It's been a while, but I
have seen -25F in winter, so I am puzzled why folks use heat pumps here.
* Had a h.p. in Florida, and when the temp got down to the forties, it
wasn't warm enough indoors with the h.p. *Is there new technology?

Conventional air source heat pumps won't work in very cold weather.
Ground source heat pumps will, or air source heat pumps using CO2 as a
refrigerant.

A major problem can be icing on the evaporator of air source heat
pumps. Depends on climate/humidity.

On Sep 15, 11:40*am, George wrote:
On 9/15/2012 11:16 AM, wrote:





On Sep 15, 10:56 am, "Ralph Mowery"
wrote:
"George" wrote in message

...

He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...20brochure%203....

According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

That sure seems like an impressive unit. *I did see what appears to be some
resistive heating elements in the individual units that seem to be an
option.

I think this is just another sales job and you're on to the
truth. *It only shows that it has 100% CAPACITY down
to 10F, not how it gets that capacity. * Unless the laws of
thermodynamics have been repealed, the efficiency of
ALL heat pumps declines as the outside temp drops.
It's a matter of physics that no manufacturer can avoid.
They can still deliver more heat than a resistive heating
element would at 10F, but the amount of heat you get
out of the heat pump drops on a steady curve as the
temp goes down.

The only way they can get 100% capacity across that
broad temp range is either by:

A - using resistive heat to supplement

B - Downrating the whole thing so that it's rated by what
it produces at 10F.

Option B is nuts for obvious reasons.

I think you would want to contact Mitsubishi and explain to them that
the systems they sell can't work as described (hint, Mitsubishi makes
really well engineered stuff and they tend to be really anal about
describing actual performance)

Then you contact my friend and let them know the performance he actually
witnessed isn't possible in his system since it doesn't have resistive
elements.

And maybe you just don't see that everyone who posts in this group isn't
heybub just telling stories to screw with people...- Hide quoted text -

- Show quoted text -


I looked at the brochure in more detail. It appears that they
do not use resistive heating elements. Now I suggest you
look at the actual spec data in the brochure. Look at
page 12, about 1/4 of the way down. It states that the
rated capacity for the first model is 10,900BTU at 47F and
6,600BTU at 17F. For the largest model, it's rated at
18,000BTU at 47F and 11,300 at 17F. And then maybe you
can explain how that jives with the performance curve
in the graph that shows 100% capacity down to 10F.
It is however consistent with physics and what we know
about heat pumps, regardless of who builds them.

On 9/16/2012 7:39 AM, wrote:
On Sep 15, 11:40 am, George wrote:
On 9/15/2012 11:16 AM, wrote:





On Sep 15, 10:56 am, "Ralph Mowery"
wrote:
"George" wrote in message

...

He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...20brochure%203...

According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

That sure seems like an impressive unit. I did see what appears to be some
resistive heating elements in the individual units that seem to be an
option.

I think this is just another sales job and you're on to the
truth. It only shows that it has 100% CAPACITY down
to 10F, not how it gets that capacity. Unless the laws of
thermodynamics have been repealed, the efficiency of
ALL heat pumps declines as the outside temp drops.
It's a matter of physics that no manufacturer can avoid.
They can still deliver more heat than a resistive heating
element would at 10F, but the amount of heat you get
out of the heat pump drops on a steady curve as the
temp goes down.

The only way they can get 100% capacity across that
broad temp range is either by:

A - using resistive heat to supplement

B - Downrating the whole thing so that it's rated by what
it produces at 10F.

Option B is nuts for obvious reasons.

I think you would want to contact Mitsubishi and explain to them that
the systems they sell can't work as described (hint, Mitsubishi makes
really well engineered stuff and they tend to be really anal about
describing actual performance)

Then you contact my friend and let them know the performance he actually
witnessed isn't possible in his system since it doesn't have resistive
elements.

And maybe you just don't see that everyone who posts in this group isn't
heybub just telling stories to screw with people...- Hide quoted text -

- Show quoted text -


I looked at the brochure in more detail. It appears that they
do not use resistive heating elements. Now I suggest you
look at the actual spec data in the brochure. Look at
page 12, about 1/4 of the way down. It states that the
rated capacity for the first model is 10,900BTU at 47F and
6,600BTU at 17F. For the largest model, it's rated at
18,000BTU at 47F and 11,300 at 17F. And then maybe you
can explain how that jives with the performance curve
in the graph that shows 100% capacity down to 10F.
It is however consistent with physics and what we know
about heat pumps, regardless of who builds them.


Isn't that a little different than it can't work and it must have
resistive elements?

"George" wrote in message
...

Isn't that a little different than it can't work and it must have
resistive elements?

Heat pumps can work at low temperatures, but depending on the unit, the
efficency is such that below a certain temperature, the resistive elements
cost less to run than the heat pump compressor system. I don't know what it
is now or with their system, but it used to be around 25 deg F. was the
break even point.

Where I live, it seldom stays below 20 deg and most of that time it is night
and warms up during the day. It has gotten to just below zero, maybe to
minus 10 about every 15 years or so during the night. The heat pumps work
fine in this area, with the resistive heat strips comming on only if the
heat pump can not maintain the house at the setpoint.

On Sep 16, 7:56*am, George wrote:
On 9/16/2012 7:39 AM, wrote:





On Sep 15, 11:40 am, George wrote:
On 9/15/2012 11:16 AM, wrote:

On Sep 15, 10:56 am, "Ralph Mowery"
wrote:
"George" wrote in message

...

He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...20brochure%203...

According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

That sure seems like an impressive unit. *I did see what appears to be some
resistive heating elements in the individual units that seem to be an
option.

I think this is just another sales job and you're on to the
truth. *It only shows that it has 100% CAPACITY down
to 10F, not how it gets that capacity. * Unless the laws of
thermodynamics have been repealed, the efficiency of
ALL heat pumps declines as the outside temp drops.
It's a matter of physics that no manufacturer can avoid.
They can still deliver more heat than a resistive heating
element would at 10F, but the amount of heat you get
out of the heat pump drops on a steady curve as the
temp goes down.

The only way they can get 100% capacity across that
broad temp range is either by:

A - using resistive heat to supplement

B - Downrating the whole thing so that it's rated by what
it produces at 10F.

Option B is nuts for obvious reasons.

I think you would want to contact Mitsubishi and explain to them that
the systems they sell can't work as described (hint, Mitsubishi makes
really well engineered stuff and they tend to be really anal about
describing actual performance)

Then you contact my friend and let them know the performance he actually
witnessed isn't possible in his system since it doesn't have resistive
elements.

And maybe you just don't see that everyone who posts in this group isn't
heybub just telling stories to screw with people...- Hide quoted text -

- Show quoted text -

I looked at the brochure in more detail. *It appears that they
do not use resistive heating elements. * Now I suggest you
look at the actual spec data in the brochure. * Look at
page 12, about 1/4 of the way down. * It states that the
rated capacity for the first model is 10,900BTU at 47F and
6,600BTU at 17F. * For the largest model, it's rated at
18,000BTU at 47F and 11,300 at 17F. *And then maybe you
can explain how that jives with the performance curve
in the graph that shows 100% capacity down to 10F.
It is however consistent with physics and what we know
about heat pumps, regardless of who builds them.

Isn't that a little different than it can't work and it must have
resistive elements?- Hide quoted text -

- Show quoted text -


The issue was how these Mitsubishi units could maintain
100% output all the way down to 10F.
In my post, to which you objected, I said there were TWO
ways they could do that:

A - They use resistance heating to supplement the output
at lower outside temps so the output remains 100% as
the temps drop.

B - They downrate the output at the higher temps so that
it's rated the same as the lower temps.

And I started off the post by saying it looks like another sales
job.

So, after you objected and defended Mitsubishi, I go back
and look at the actual performance data in the specs in the
same brochure. And those specs show that the rated
capacity at 47F is 10,900BTU while at 17F it's only 6,600BTU.
It has 60% the heating capacity at 17F that in has at 47F.
Exactly what we expect from a heat pump. So, it was not
option A or B, just another sales job, ie marketing BS.

I never said it had resistive heating elements for sure.
And apparently I was spot on when I said it looked like
another sales job. You bought the BS hook line
and sinker and when I pointed out that it doesn't add up, you
defended it as an example of great
engineering from Mistsubishi. The issue wasn't whether it
has resistance heating elements. The issue is that graph
is some kind of marketing BS, and it is not some miracle unit
that has the same heat output at 10F that it does at 47F.

You still think these are some wonder units that defy the
laws of physics?

On 9/17/2012 8:26 AM, wrote:
On Sep 16, 7:56 am, George wrote:
On 9/16/2012 7:39 AM, wrote:





On Sep 15, 11:40 am, George wrote:
On 9/15/2012 11:16 AM, wrote:

On Sep 15, 10:56 am, "Ralph Mowery"
wrote:
"George" wrote in message

...

He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...20brochure%203...

According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

That sure seems like an impressive unit. I did see what appears to be some
resistive heating elements in the individual units that seem to be an
option.

I think this is just another sales job and you're on to the
truth. It only shows that it has 100% CAPACITY down
to 10F, not how it gets that capacity. Unless the laws of
thermodynamics have been repealed, the efficiency of
ALL heat pumps declines as the outside temp drops.
It's a matter of physics that no manufacturer can avoid.
They can still deliver more heat than a resistive heating
element would at 10F, but the amount of heat you get
out of the heat pump drops on a steady curve as the
temp goes down.

The only way they can get 100% capacity across that
broad temp range is either by:

A - using resistive heat to supplement

B - Downrating the whole thing so that it's rated by what
it produces at 10F.

Option B is nuts for obvious reasons.

I think you would want to contact Mitsubishi and explain to them that
the systems they sell can't work as described (hint, Mitsubishi makes
really well engineered stuff and they tend to be really anal about
describing actual performance)

Then you contact my friend and let them know the performance he actually
witnessed isn't possible in his system since it doesn't have resistive
elements.

And maybe you just don't see that everyone who posts in this group isn't
heybub just telling stories to screw with people...- Hide quoted text -

- Show quoted text -

I looked at the brochure in more detail. It appears that they
do not use resistive heating elements. Now I suggest you
look at the actual spec data in the brochure. Look at
page 12, about 1/4 of the way down. It states that the
rated capacity for the first model is 10,900BTU at 47F and
6,600BTU at 17F. For the largest model, it's rated at
18,000BTU at 47F and 11,300 at 17F. And then maybe you
can explain how that jives with the performance curve
in the graph that shows 100% capacity down to 10F.
It is however consistent with physics and what we know
about heat pumps, regardless of who builds them.

Isn't that a little different than it can't work and it must have
resistive elements?- Hide quoted text -

- Show quoted text -


The issue was how these Mitsubishi units could maintain
100% output all the way down to 10F.
In my post, to which you objected, I said there were TWO
ways they could do that:

A - They use resistance heating to supplement the output
at lower outside temps so the output remains 100% as
the temps drop.

B - They downrate the output at the higher temps so that
it's rated the same as the lower temps.

And I started off the post by saying it looks like another sales
job.

So, after you objected and defended Mitsubishi, I go back
and look at the actual performance data in the specs in the
same brochure. And those specs show that the rated
capacity at 47F is 10,900BTU while at 17F it's only 6,600BTU.
It has 60% the heating capacity at 17F that in has at 47F.
Exactly what we expect from a heat pump. So, it was not
option A or B, just another sales job, ie marketing BS.

I never said it had resistive heating elements for sure.
And apparently I was spot on when I said it looked like
another sales job. You bought the BS hook line
and sinker and when I pointed out that it doesn't add up, you
defended it as an example of great
engineering from Mistsubishi. The issue wasn't whether it
has resistance heating elements. The issue is that graph
is some kind of marketing BS, and it is not some miracle unit
that has the same heat output at 10F that it does at 47F.

You still think these are some wonder units that defy the
laws of physics?

Let's see. You get 3.413 BTU per watt hour of electricity for
resistance heat. For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. Plus you have the add the indoor fan. And, I know,
I didn't add anything for power factor. But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.

On Sep 17, 9:23*am, Art Todesco wrote:
On 9/17/2012 8:26 AM, wrote:



On Sep 16, 7:56 am, George wrote:
On 9/16/2012 7:39 AM, wrote:

On Sep 15, 11:40 am, George wrote:
On 9/15/2012 11:16 AM, wrote:

On Sep 15, 10:56 am, "Ralph Mowery"
wrote:
"George" wrote in message

...

He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...20brochure%203...

According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

That sure seems like an impressive unit. *I did see what appears to be some
resistive heating elements in the individual units that seem to be an
option.

I think this is just another sales job and you're on to the
truth. *It only shows that it has 100% CAPACITY down
to 10F, not how it gets that capacity. * Unless the laws of
thermodynamics have been repealed, the efficiency of
ALL heat pumps declines as the outside temp drops.
It's a matter of physics that no manufacturer can avoid.
They can still deliver more heat than a resistive heating
element would at 10F, but the amount of heat you get
out of the heat pump drops on a steady curve as the
temp goes down.

The only way they can get 100% capacity across that
broad temp range is either by:

A - using resistive heat to supplement

B - Downrating the whole thing so that it's rated by what
it produces at 10F.

Option B is nuts for obvious reasons.

I think you would want to contact Mitsubishi and explain to them that
the systems they sell can't work as described (hint, Mitsubishi makes
really well engineered stuff and they tend to be really anal about
describing actual performance)

Then you contact my friend and let them know the performance he actually
witnessed isn't possible in his system since it doesn't have resistive
elements.

And maybe you just don't see that everyone who posts in this group isn't
heybub just telling stories to screw with people...- Hide quoted text -

- Show quoted text -

I looked at the brochure in more detail. *It appears that they
do not use resistive heating elements. * Now I suggest you
look at the actual spec data in the brochure. * Look at
page 12, about 1/4 of the way down. * It states that the
rated capacity for the first model is 10,900BTU at 47F and
6,600BTU at 17F. * For the largest model, it's rated at
18,000BTU at 47F and 11,300 at 17F. *And then maybe you
can explain how that jives with the performance curve
in the graph that shows 100% capacity down to 10F.
It is however consistent with physics and what we know
about heat pumps, regardless of who builds them.

Isn't that a little different than it can't work and it must have
resistive elements?- Hide quoted text -

- Show quoted text -

The issue was how these Mitsubishi units could maintain
100% output all the way down to 10F.
In my post, to which you objected, I said there were TWO
ways they could do that:

A - They use resistance heating to supplement the output
at lower outside temps so the output remains 100% as
the temps drop.

B - They downrate the output at the higher temps so that
it's rated the same as the lower temps.

And I started off the post by saying it looks like another sales
job.

So, after you objected and defended Mitsubishi, I go back
and look at the actual performance data in the specs in the
same brochure. *And those specs show that the rated
capacity at 47F is 10,900BTU *while at 17F it's only 6,600BTU.
It has 60% the heating capacity at 17F that in has at 47F.
Exactly what we expect from a heat pump. *So, it was not
option A or B, just another sales job, ie marketing BS.

I never said it had resistive heating elements for sure.
And apparently I was spot on when I said it looked like
another sales job. *You bought the BS hook line
and sinker and when I pointed out that it doesn't add up, you
defended it as an example of great
engineering from Mistsubishi. * The issue wasn't whether it
has resistance heating elements. * The issue is that graph
is some kind of marketing BS, and it is not some miracle unit
that has the same heat output at 10F that it does at 47F.

You still think these are some wonder units that defy the
laws of physics?

Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc. If they only produced heating
similar to resistive heating, you wouldn't see them used
and you wouldn't have folks bitching about the high
electric bill that occurs when they go to resistive heat
mode.

On Mon, 17 Sep 2012 06:39:29 -0700 (PDT), "
wrote:

On Sep 17, 9:23*am, Art Todesco wrote:
On 9/17/2012 8:26 AM, wrote:



On Sep 16, 7:56 am, George wrote:
On 9/16/2012 7:39 AM, wrote:

On Sep 15, 11:40 am, George wrote:
On 9/15/2012 11:16 AM, wrote:

On Sep 15, 10:56 am, "Ralph Mowery"
wrote:
"George" wrote in message

...

He has a Mitsubishi inverter multi zone heat pump (split system). It
doesn't have any resistive elements.

http://www.mitsubishicomfort.com/med...20brochure%203...

According to the graph it has 100% heating capacity down to 5F outside
which tails off to 73% at -13F.

That sure seems like an impressive unit. *I did see what appears to be some
resistive heating elements in the individual units that seem to be an
option.

I think this is just another sales job and you're on to the
truth. *It only shows that it has 100% CAPACITY down
to 10F, not how it gets that capacity. * Unless the laws of
thermodynamics have been repealed, the efficiency of
ALL heat pumps declines as the outside temp drops.
It's a matter of physics that no manufacturer can avoid.
They can still deliver more heat than a resistive heating
element would at 10F, but the amount of heat you get
out of the heat pump drops on a steady curve as the
temp goes down.

The only way they can get 100% capacity across that
broad temp range is either by:

A - using resistive heat to supplement

B - Downrating the whole thing so that it's rated by what
it produces at 10F.

Option B is nuts for obvious reasons.

I think you would want to contact Mitsubishi and explain to them that
the systems they sell can't work as described (hint, Mitsubishi makes
really well engineered stuff and they tend to be really anal about
describing actual performance)

Then you contact my friend and let them know the performance he actually
witnessed isn't possible in his system since it doesn't have resistive
elements.

And maybe you just don't see that everyone who posts in this group isn't
heybub just telling stories to screw with people...- Hide quoted text -

- Show quoted text -

I looked at the brochure in more detail. *It appears that they
do not use resistive heating elements. * Now I suggest you
look at the actual spec data in the brochure. * Look at
page 12, about 1/4 of the way down. * It states that the
rated capacity for the first model is 10,900BTU at 47F and
6,600BTU at 17F. * For the largest model, it's rated at
18,000BTU at 47F and 11,300 at 17F. *And then maybe you
can explain how that jives with the performance curve
in the graph that shows 100% capacity down to 10F.
It is however consistent with physics and what we know
about heat pumps, regardless of who builds them.

Isn't that a little different than it can't work and it must have
resistive elements?- Hide quoted text -

- Show quoted text -

The issue was how these Mitsubishi units could maintain
100% output all the way down to 10F.
In my post, to which you objected, I said there were TWO
ways they could do that:

A - They use resistance heating to supplement the output
at lower outside temps so the output remains 100% as
the temps drop.

B - They downrate the output at the higher temps so that
it's rated the same as the lower temps.

And I started off the post by saying it looks like another sales
job.

So, after you objected and defended Mitsubishi, I go back
and look at the actual performance data in the specs in the
same brochure. *And those specs show that the rated
capacity at 47F is 10,900BTU *while at 17F it's only 6,600BTU.
It has 60% the heating capacity at 17F that in has at 47F.
Exactly what we expect from a heat pump. *So, it was not
option A or B, just another sales job, ie marketing BS.

I never said it had resistive heating elements for sure.
And apparently I was spot on when I said it looked like
another sales job. *You bought the BS hook line
and sinker and when I pointed out that it doesn't add up, you
defended it as an example of great
engineering from Mistsubishi. * The issue wasn't whether it
has resistance heating elements. * The issue is that graph
is some kind of marketing BS, and it is not some miracle unit
that has the same heat output at 10F that it does at 47F.

You still think these are some wonder units that defy the
laws of physics?

Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data. What's missing here is
that not all of the heat is useful. Some of it is created by the outside unit
so doesn't contribute. As noted (by everyone here) the efficiency of a heat
pump goes down with rising delta-T. At some point the "heat pumped" = "wasted
heat", so resistive heat would be equally as efficient.

If they only produced heating
similar to resistive heating, you wouldn't see them used
and you wouldn't have folks bitching about the high
electric bill that occurs when they go to resistive heat
mode.

No, resistive heat is still 2-3x the cost of heat from a heat pump. People do
bitch when their bills go up 4-5x. How many really know what it would cost to
heat with resistive heat?

On Sep 17, 1:28*pm, "
wrote:


Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. *Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.

His bottom line is that he is saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

Why do you think people bother with heat pumps at all
if you get about the same amount of heat from a resistance
heater? Everyone would just use a cheaper resistance heater
where ALL the heat would go into the house.


Obviously *What's missing here is
that not all of the heat is useful. *Some of it is created by the outside unit
so doesn't contribute.

Obviously what is missing here is that you are wrong.
OK so according to the two of you, the total heat generated
by a heat pump is about the same as a resistance heater
that uses an equivalent amount of electricity. And according
to you, some of that heat doesn't make it into the house with
a heat pump because it's lost outside. Therefore, a heat pump
system would produce LESS heat into the house than a
resistance heater?
Not in my world of physics. Nor in the world where you see
heat pumps used because they deliver a lot more heat for
the same electricity usage as a resistance heater.





*As noted (by everyone here) the efficiency of a heat
pump goes down with rising delta-T.


At some point the "heat pumped" = "wasted
heat", so resistive heat would be equally as efficient.

If they only produced heating
similar to resistive heating, you wouldn't see them used
and you wouldn't have folks bitching about the high
electric bill that occurs when they go to resistive heat
mode.

No, resistive heat is still 2-3x the cost of heat from a heat pump.

Now, why on earth would that be? You agree with the
faulty analysis that says the heat pump only generates
heat about equivalent to a resistive heater. And you say the
other issue is that with the heat pump, some of that heat is also
lost outside. So, how could resistive heat cost 2 -3X as
much?

Now go ahead, instead of admitting you made a mistake, double
down and as usual start with the name calling.

On Tue, 18 Sep 2012 06:26:59 -0700 (PDT), "
wrote:

On Sep 17, 1:28*pm, "
wrote:


Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. *Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.

His bottom line is that he is saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

At some low temperature, yes.

Why do you think people bother with heat pumps at all
if you get about the same amount of heat from a resistance
heater? Everyone would just use a cheaper resistance heater
where ALL the heat would go into the house.

Good Lord! Read!

Obviously *What's missing here is
that not all of the heat is useful. *Some of it is created by the outside unit
so doesn't contribute.

Obviously what is missing here is that you are wrong.

Nope, but it wouldn't be the first time you've been completely wrong.
Illiteracy will do that.

OK so according to the two of you,

I've noticed that whenever you say the above, you're lying.

the total heat generated by a heat pump is about the same as a resistance heater
that uses an equivalent amount of electricity.

Yep. You're lying again.

And according
to you, some of that heat doesn't make it into the house with
a heat pump because it's lost outside.

No, some of it is "generated" outside.

Therefore, a heat pump
system would produce LESS heat into the house than a
resistance heater?

If some is outside (it is), at some (low) temperature, certainly. As the
efficiency of the system goes down, at some point the gain from pumping is
offset by the energy dissipated (uselessly) outside. At that point the heat
pump costs exactly the same as resistive heat, to operate.

Not in my world of physics. Nor in the world where you see
heat pumps used because they deliver a lot more heat for
the same electricity usage as a resistance heater.

Idiot. As the temperature goes down, the efficiency goes down (at some point
it stops working altogether) and the energy hill gets higher. Somewhere along
the line the unit can no longer push heat up the hill. If there is heat lost
outside (there is), the unit is no longer putting out more heat than the
electricity it's consuming (total inside and out - both cost the same $$).

*As noted (by everyone here) the efficiency of a heat
pump goes down with rising delta-T.


At some point the "heat pumped" = "wasted
heat", so resistive heat would be equally as efficient.

If they only produced heating
similar to resistive heating, you wouldn't see them used
and you wouldn't have folks bitching about the high
electric bill that occurs when they go to resistive heat
mode.

No, resistive heat is still 2-3x the cost of heat from a heat pump.

Now, why on earth would that be?

Are you really that stupid? If a heat pump moves twice as much heat as it
uses, it costs 1/2 to 1/3 as much as resistive heat (resistive heat costs 2-3x
more).

You agree

There's that lie tell, again.

with the
faulty analysis that says the heat pump only generates
heat about equivalent to a resistive heater.

Yep. At some point, resistive heat will be on par with a heat pump. Gotta
be.

And you say the
other issue is that with the heat pump, some of that heat is also
lost outside. So, how could resistive heat cost 2 -3X as
much?

You really are that stupid. Amazing.

Now go ahead, instead of admitting you made a mistake, double
down and as usual start with the name calling.

I made no mistake. You're simply too stupid to read. ...or think.

On 9/18/2012 11:14 AM, zzzzzzzzzz wrote:
On Tue, 18 Sep 2012 06:26:59 -0700 (PDT), "
wrote:

On Sep 17, 1:28 pm, "
wrote:


Let's see. You get 3.413 BTU per watt hour of electricity for
resistance heat. For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. Plus you have the add the indoor fan. And, I know,
I didn't add anything for power factor. But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.

His bottom line is that he is saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

At some low temperature, yes.

Why do you think people bother with heat pumps at all
if you get about the same amount of heat from a resistance
heater? Everyone would just use a cheaper resistance heater
where ALL the heat would go into the house.

Good Lord! Read!

Obviously What's missing here is
that not all of the heat is useful. Some of it is created by the outside unit
so doesn't contribute.

Obviously what is missing here is that you are wrong.

Nope, but it wouldn't be the first time you've been completely wrong.
Illiteracy will do that.

OK so according to the two of you,

I've noticed that whenever you say the above, you're lying.

the total heat generated by a heat pump is about the same as a resistance heater
that uses an equivalent amount of electricity.

Yep. You're lying again.

And according
to you, some of that heat doesn't make it into the house with
a heat pump because it's lost outside.

No, some of it is "generated" outside.

Therefore, a heat pump
system would produce LESS heat into the house than a
resistance heater?

If some is outside (it is), at some (low) temperature, certainly. As the
efficiency of the system goes down, at some point the gain from pumping is
offset by the energy dissipated (uselessly) outside. At that point the heat
pump costs exactly the same as resistive heat, to operate.

Not in my world of physics. Nor in the world where you see
heat pumps used because they deliver a lot more heat for
the same electricity usage as a resistance heater.

Idiot. As the temperature goes down, the efficiency goes down (at some point
it stops working altogether) and the energy hill gets higher. Somewhere along
the line the unit can no longer push heat up the hill. If there is heat lost
outside (there is), the unit is no longer putting out more heat than the
electricity it's consuming (total inside and out - both cost the same $$).

As noted (by everyone here) the efficiency of a heat
pump goes down with rising delta-T.


At some point the "heat pumped" = "wasted
heat", so resistive heat would be equally as efficient.

If they only produced heating
similar to resistive heating, you wouldn't see them used
and you wouldn't have folks bitching about the high
electric bill that occurs when they go to resistive heat
mode.

No, resistive heat is still 2-3x the cost of heat from a heat pump.

Now, why on earth would that be?

Are you really that stupid? If a heat pump moves twice as much heat as it
uses, it costs 1/2 to 1/3 as much as resistive heat (resistive heat costs 2-3x
more).

You agree

There's that lie tell, again.

with the
faulty analysis that says the heat pump only generates
heat about equivalent to a resistive heater.

Yep. At some point, resistive heat will be on par with a heat pump. Gotta
be.

And you say the
other issue is that with the heat pump, some of that heat is also
lost outside. So, how could resistive heat cost 2 -3X as
much?

You really are that stupid. Amazing.

Now go ahead, instead of admitting you made a mistake, double
down and as usual start with the name calling.

I made no mistake. You're simply too stupid to read. ...or think.

Ok, here's some explanation on my earlier post. The BTUs/KWHr (3.413)
came from the internet, which seems about right. The average 1500 watt
electric heater is usually in listed (if you can find it) at about 5K
BTUs. The numbers for the heat pump came from the manufacturer's sheet
posted earlier in this thread, for 17 degrees outdoor air temp. Sorry I
missed the part about "at 17 degrees." Now, if the outside air is 45
degrees, you'd see much bigger BTU numbers. And, of course, that's why
we use heat pumps. But at 17 degrees, the inside are will probably feel
cold, even though there is some heat being added.

On Sep 18, 1:17*pm, Art Todesco wrote:
On 9/18/2012 11:14 AM, wrote:



On Tue, 18 Sep 2012 06:26:59 -0700 (PDT), "
wrote:

On Sep 17, 1:28 pm, "
wrote:

Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. *Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. *He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.

His bottom line is that he is *saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

At some low temperature, yes.

Why do you think people bother with heat pumps at all
if you get about the same amount of heat from a resistance
heater? * Everyone would just use a cheaper resistance heater
where ALL the heat would go into the house.

Good Lord! *Read!

Obviously *What's missing here is
that not all of the heat is useful. *Some of it is created by the outside unit
so doesn't contribute.

Obviously what is missing here is that you are wrong.

Nope, but it wouldn't be the first time you've been completely wrong.
Illiteracy will do that.

OK so according to the two of you,

I've noticed that whenever you say the above, you're lying.

the total heat generated by a heat pump is about the same as a resistance heater
that uses an equivalent amount of electricity.

Yep. *You're lying again.

And according
to you, some of that heat doesn't make it into the house with
a heat pump because it's lost outside.

No, some of it is "generated" outside.

Therefore, a heat pump
system would produce LESS heat into the house than a
resistance *heater?

If some is outside (it is), at some (low) temperature, certainly. *As the
efficiency of the system goes down, at some point the gain from pumping is
offset by the energy dissipated (uselessly) outside. *At that point the heat
pump costs exactly the same as resistive heat, to operate.

Not in my world of physics. *Nor in the world where you see
heat pumps used because they deliver a lot more heat for
the same electricity usage as a resistance heater.

Idiot. *As the temperature goes down, the efficiency goes down (at some point
it stops working altogether) and the energy hill gets higher. *Somewhere along
the line the unit can no longer push heat up the hill. If there is heat lost
outside (there is), the unit is no longer putting out more heat than the
electricity it's consuming (total inside and out - both cost the same $$).

* As noted (by everyone here) the efficiency of a heat
pump goes down with rising delta-T.

At some point the "heat pumped" = "wasted
heat", so resistive heat would be equally as efficient.

If they only produced heating
similar to resistive heating, you wouldn't see them used
and you wouldn't have folks bitching about the high
electric bill that occurs when they go to resistive heat
mode.

No, resistive heat is still 2-3x the cost of heat from a heat pump.

Now, why on earth would that be?

Are you really that stupid? *If a heat pump moves twice as much heat as it
uses, it costs 1/2 to 1/3 as much as resistive heat (resistive heat costs 2-3x
more).

You agree

There's that lie tell, again.

with the
faulty analysis that says the heat pump only generates
heat about equivalent to a resistive heater.

Yep. *At some point, resistive heat will be on par with a heat pump. *Gotta
be.

And you say the
other issue is that with the heat pump, some of that heat is also
lost outside. *So, how could *resistive heat cost 2 -3X as
much?

You *really are that stupid. *Amazing.

Now go ahead, instead of admitting you made a mistake, double
down and as usual start with the name calling.

I made no mistake. *You're simply too stupid to read. * ...or think..

Ok, here's some explanation on my earlier post. *The BTUs/KWHr (3.413)
came from the internet, which seems about right. *The average 1500 watt
electric heater is usually in listed (if you can find it) at about 5K
BTUs.

OK, that part I agree with. A 1500 watt electric heater
would give you 5100 BTU.



*The numbers for the heat pump came from the manufacturer's sheet
posted earlier in this thread, for 17 degrees outdoor air temp. *Sorry I
missed the part about "at 17 degrees."


The numbers for what and from where? There are
multiple units listed with multiple specs for each.
It would be helpful if you could
specify what table entry you are using and for which
model. Let's look at the specs for the MSZ-GE09NA
which are on page 12 of the brochu

http://www.mitsubishicomfort.com/med...11-r_pages.pdf

At 17F it states:

Rated Capacity: 6600BTU
Rated Total Input: 700W

A 700W resistance heater would generate
700 x 3.41 = 2387 BTU
The heat pump is generating 6600 BTU
Meaning the heat pump is generating 2.7 times
more heat at 17F outside temp than you would get
with a resistance heater using the same amount
of electricity.



* Now, if the outside air is 45
degrees, you'd see much bigger BTU numbers. *And, of course, that's why
we use heat pumps. *But at 17 degrees, the inside are will probably feel
cold, even though there is some heat being added.- Hide quoted text -


From the same specs, it gives the capacity at 47F as
10,900 BTU. The capacity at 17F is 6,600 which
means you're still getting 60% of the heat that you get
at 47F.

Now the part that I don't understand is the graph earlier in
the brochure that shows capacity staying constant all the
way down to 10F. I think we agree that sounds like marketing
BS of some kind, given that it does not have resistive heating.

On Sep 18, 11:14*am, "
wrote:
On Tue, 18 Sep 2012 06:26:59 -0700 (PDT), "





wrote:
On Sep 17, 1:28*pm, "
wrote:

Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. *Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. *He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.
His bottom line is that he is *saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

At some low temperature, yes.

There we have it folks. The usual KRW tactic. Try to now
change the discussion into something else. Art stated:

" But, it shows that you are almost getting the same amount
of heat as you would if it were a resistive heater. "

There was no qualification of temperature. Now, having been
wrong, just as I predicted, you try to weasel away by now
adding "at some low temperatures" into it.




Why do you think people bother with heat pumps at all
if you get about the same amount of heat from a resistance
heater? * Everyone would just use a cheaper resistance heater
where ALL the heat would go into the house.

Good Lord! *Read!

Obviously *What's missing here is
that not all of the heat is useful. *Some of it is created by the outside unit
so doesn't contribute.

Obviously what is missing here is that you are wrong.

Nope, but it wouldn't be the first time you've been completely wrong.
Illiteracy will do that.

OK so according to the two of you,

I've noticed that whenever you say the above, you're lying.

the total heat generated by a heat pump is about the same as a resistance heater
that uses an equivalent amount of electricity.

Yep. *You're lying again.

And according
to you, some of that heat doesn't make it into the house with
a heat pump because it's lost outside.

No, some of it is "generated" outside.

Therefore, a heat pump
system would produce LESS heat into the house than a
resistance *heater?

If some is outside (it is), at some (low) temperature, certainly. *As the
efficiency of the system goes down, at some point the gain from pumping is
offset by the energy dissipated (uselessly) outside. *At that point the heat
pump costs exactly the same as resistive heat, to operate.

Not in my world of physics. *Nor in the world where you see
heat pumps used because they deliver a lot more heat for
the same electricity usage as a resistance heater.

Idiot. *As the temperature goes down, the efficiency goes down (at some point
it stops working altogether) and the energy hill gets higher. *Somewhere along
the line the unit can no longer push heat up the hill. If there is heat lost
outside (there is), the unit is no longer putting out more heat than the
electricity it's consuming (total inside and out - both cost the same $$)..



Perhaps you should look at the data sheet for the Mitsubishi units
under discussion instead of embarrasing yourself further. Per the
analysis I showed in my last reply to Art,
at 17F, the MSZ-GE09NA is producing 2.7 times the heat that you
would get from a resistance heater. That's pretty impressive
performance in cold temps.

And it sure doesn't jive with:

"" But, it shows that you are almost getting the same amount
of heat as you would if it were a resistive heater. "








*As noted (by everyone here) the efficiency of a heat
pump goes down with rising delta-T.

At some point the "heat pumped" = "wasted
heat", so resistive heat would be equally as efficient.

If they only produced heating
similar to resistive heating, you wouldn't see them used
and you wouldn't have folks bitching about the high
electric bill that occurs when they go to resistive heat
mode.

No, resistive heat is still 2-3x the cost of heat from a heat pump.

Now, why on earth would that be?

Are you really that stupid? *If a heat pump moves twice as much heat as it
uses, it costs 1/2 to 1/3 as much as resistive heat (resistive heat costs 2-3x
more).

YOU are the one that agreed with the analysis that the
heat pump only generates about as much heat as an
equivalent resistance heater. YOU were agreeing that it
only moves the same amount of heat as it uses.
Now of course, you're trying to weasle away, by
adding "at some low temps" At 17F it's still generating
2.7 times the heat you'd get from a resistance heater.
Even at 5F it's still generating far more heat than a
resistance heater.

And as predicted, instead of being a man and admitting
your error, you've quickly resorted to name calling.

On Tue, 18 Sep 2012 12:28:01 -0700 (PDT), "
wrote:

On Sep 18, 11:14*am, "
wrote:
On Tue, 18 Sep 2012 06:26:59 -0700 (PDT), "





wrote:
On Sep 17, 1:28*pm, "
wrote:

Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. *Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. *He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.
His bottom line is that he is *saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

At some low temperature, yes.

There we have it folks. The usual KRW tactic. Try to now
change the discussion into something else. Art stated:

Wong, liar. The discussion *was* about operation and efficiencies at lower
temperatures.

" But, it shows that you are almost getting the same amount
of heat as you would if it were a resistive heater. "

....at low temperatures.

There was no qualification of temperature. Now, having been
wrong, just as I predicted, you try to weasel away by now
adding "at some low temperatures" into it.

You really are an idiot. That's what the discussion was about. What a stupid
liar.

nothing else worth reading

On Sep 18, 3:47*pm, "
wrote:
On Tue, 18 Sep 2012 12:28:01 -0700 (PDT), "





wrote:
On Sep 18, 11:14*am, "
wrote:
On Tue, 18 Sep 2012 06:26:59 -0700 (PDT), "

wrote:
On Sep 17, 1:28*pm, "
wrote:

Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. *Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. *He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.
His bottom line is that he is *saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

At some low temperature, yes.

There we have it folks. *The usual KRW tactic. *Try to now
change the discussion into something else. *Art stated:

Wong, liar. *The discussion *was* about operation and efficiencies at lower
temperatures.

" But, it shows that you are *almost getting the same amount
of heat as you would if it were a *resistive heater. "

...at low temperatures.

There was no qualification of temperature. *Now, having been
wrong, just as I predicted, you try to weasel away by now
adding "at some low temperatures" into it.

You really are an idiot. *That's what the discussion was about. *What a stupid
liar.


Show me where Art gave a temp that his statment applied to.
Typically YOU would be the one to jump all over something like
that, because it's open ended, generally not true, and
meaningless without specifying what temps you are talking about.

He now says it was at 17F that his analysis was done.
Well, per the Mitstubishi data sheet, which you obviously have
not even bothered to read,
page 12, at 17F you get 2.7 times the heat output that you would
with a resistance heater. That is not about the same amount of
heat as a resistance heater, it's 2.7 times greater. Art made a
mistake.
YOU agreed with the analysis which is TOTALLY WRONG and
instead of admit it, as usual, you start the name calling.
Try reading the datasheet instead of embarrassing yourself.



nothing else worth reading- Hide quoted text -

- Show quoted text -

YOU agreed with a faulty analysis that didn't even mention
what temperature it applied to. Now in my world when someone
says:

" But, it shows that you are almost getting the same amount
of heat as you would if it were a resistive heater. "

It's a very broad indictment of heat pumps. And what that
faulty analysis was based on, I still don't know because Art
didn't say what numbers he was using. You obviously
have not done any analysis. I did. And per the Mistubishi data
sheet specs, at 17F your're getting 2.7 times the heat out of
their heat pump unit than you do with a resistance heater.
Now for most people, 17F is a pretty cold climate. And
per the Mitusbishi brochure, it's still nowhere near a resistance
heater all the way down to 5F.

On Tue, 18 Sep 2012 13:07:44 -0700 (PDT), "
wrote:

On Sep 18, 3:47*pm, "
wrote:
On Tue, 18 Sep 2012 12:28:01 -0700 (PDT), "





wrote:
On Sep 18, 11:14*am, "
wrote:
On Tue, 18 Sep 2012 06:26:59 -0700 (PDT), "

wrote:
On Sep 17, 1:28*pm, "
wrote:

Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. *Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. *He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.
His bottom line is that he is *saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

At some low temperature, yes.

There we have it folks. *The usual KRW tactic. *Try to now
change the discussion into something else. *Art stated:

Wong, liar. *The discussion *was* about operation and efficiencies at lower
temperatures.

" But, it shows that you are *almost getting the same amount
of heat as you would if it were a *resistive heater. "

...at low temperatures.

There was no qualification of temperature. *Now, having been
wrong, just as I predicted, you try to weasel away by now
adding "at some low temperatures" into it.

You really are an idiot. *That's what the discussion was about. *What a stupid
liar.


Show me where Art gave a temp that his statment applied to.
Typically YOU would be the one to jump all over something like
that, because it's open ended, generally not true, and
meaningless without specifying what temps you are talking about.

Read the ****ing thread for once. What a dumbass.

snipped nothing useful - seldom is once Trader gets involved

On Sep 18, 6:30*pm, "
wrote:
On Tue, 18 Sep 2012 13:07:44 -0700 (PDT), "





wrote:
On Sep 18, 3:47*pm, "
wrote:
On Tue, 18 Sep 2012 12:28:01 -0700 (PDT), "

wrote:
On Sep 18, 11:14*am, "
wrote:
On Tue, 18 Sep 2012 06:26:59 -0700 (PDT), "

wrote:
On Sep 17, 1:28*pm, "
wrote:

Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. *Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. *He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.
His bottom line is that he is *saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

At some low temperature, yes.

There we have it folks. *The usual KRW tactic. *Try to now
change the discussion into something else. *Art stated:

Wong, liar. *The discussion *was* about operation and efficiencies at lower
temperatures.

" But, it shows that you are *almost getting the same amount
of heat as you would if it were a *resistive heater. "

...at low temperatures.

There was no qualification of temperature. *Now, having been
wrong, just as I predicted, you try to weasel away by now
adding "at some low temperatures" into it.

You really are an idiot. *That's what the discussion was about. *What a stupid
liar.

Show me where Art gave a temp that his statment applied to.
Typically YOU would be the one to jump all over something like
that, because it's open ended, generally not true, and
meaningless without specifying what temps you are talking about.

Read the ****ing thread for once. *What a dumbass.

snipped nothing useful - seldom is once Trader gets involved- Hide quoted text -

- Show quoted text -

As usual, defeated with the basic facts, KRW resorts to
name calling and vulgarity. Face it, you never looked at
the performance data. If you had, you would have known
that the statement Art made was incorrect:

"But, it shows that you are almost getting the same amount
of heat as you would if it were a resistive heater."

A specific temp range was never included in that blanket
statement regarding heat pumps. But Art later said it was
based on 17F. Well, per the basic facts straight from the
Mitsubishi spec sheet, Art made a mistake. The heat pump
isn't about the same as a resistance heater. It produces
2.7 times as much heat at 17F as a resistive heater would.
It's still producing way more heat than a resistive heater
even at 5F. I provided the analysis that shows that using
the spec sheet. Where is YOUR analysis? You have no
numbers from the data sheet, just your flapping gums.

And as usual, instead of being a man and admitting you're
wrong, you start with the vulgarity. You really do have
issues you know. It must be a hell of way to go through life,
unable to admit a mistake.

On Tue, 18 Sep 2012 16:33:24 -0700 (PDT), "
wrote:

On Sep 18, 6:30*pm, "
wrote:
On Tue, 18 Sep 2012 13:07:44 -0700 (PDT), "





wrote:
On Sep 18, 3:47*pm, "
wrote:
On Tue, 18 Sep 2012 12:28:01 -0700 (PDT), "

wrote:
On Sep 18, 11:14*am, "
wrote:
On Tue, 18 Sep 2012 06:26:59 -0700 (PDT), "

wrote:
On Sep 17, 1:28*pm, "
wrote:

Let's see. *You get 3.413 BTU per watt hour of electricity for
resistance heat. *For the outside unit, that comes to about 1630 watts
or 5570 BTUs if you put the power into a resistor instead of the
compressor and fan. *Plus you have the add the indoor fan. *And, I know,
I didn't add anything for power factor. *But, it shows that you are
almost getting the same amount of heat as you would if it were a
resistive heater.- Hide quoted text -

- Show quoted text -

You didn't document the numbers you were using, but I
don't believe the analysis is correct. *Any heat pump
system is going to give you a lot more heat out than
a resistive heater, 2 to 4 times as much depending on
the design, temps, etc.

His analysis is correct, as I understand the data.

His "analysis" doesn't make any sense. *He doesn't
even make it clear which heat pump unit he's talking
about so we can see what numbers he's using.
His bottom line is that he is *saying that with a heat pump
you get about the same amount of heat as you would with
a resistive heating element that consumes equal electricity.

At some low temperature, yes.

There we have it folks. *The usual KRW tactic. *Try to now
change the discussion into something else. *Art stated:

Wong, liar. *The discussion *was* about operation and efficiencies at lower
temperatures.

" But, it shows that you are *almost getting the same amount
of heat as you would if it were a *resistive heater. "

...at low temperatures.

There was no qualification of temperature. *Now, having been
wrong, just as I predicted, you try to weasel away by now
adding "at some low temperatures" into it.

You really are an idiot. *That's what the discussion was about. *What a stupid
liar.

Show me where Art gave a temp that his statment applied to.
Typically YOU would be the one to jump all over something like
that, because it's open ended, generally not true, and
meaningless without specifying what temps you are talking about.

Read the ****ing thread for once. *What a dumbass.

snipped nothing useful - seldom is once Trader gets involved- Hide quoted text -

- Show quoted text -

As usual, defeated with the basic facts, KRW resorts to
name calling and vulgarity. Face it, you never looked at
the performance data. If you had, you would have known
that the statement Art made was incorrect:

As usual, instead of reading, Trader lies. You can set your watch by it.