Bill,

Feel free to offer this factual information about air-to-air heat
pumps
to
your bloggers.

1) Heat pump installations work best in locations where the heating
load in
winter nearly matches the cooling load in summer. This is usually not
the
case.

2) Heat pumps work best when maintaining a constant set point (i.e. no
drastic set point changes or night setback).

3) A heat pump cannot supply all the heat a building will need except
in
warmer climates without supplementary resistance heat. A heat pump is
basically a cooling unit and is typically sized for that purpose. Over
sizing
the unit to gain heating capacity will result in poor summer
operation.
The
oversized unit will short cycle, causing inadequate humidity control.

4) It is essential that the defrost cycle be working properly or
airflow will
be restricted through the outside coil at below freezing temperatures
lowering heat transfer and efficiency.

5) The resistance heat is in use during the defrost cycle.

6) Heat pump efficiency is mathematically greater than electrical
resistance
heat when it's warm outside. Coefficient of Performance for heat pumps
are
rated at 47 degrees F.

7) A heat pumps capacity, hence its efficiency drops as outside air
temperature drops. Efficiency drops rapidly below 32 degrees F.

8) Heat loss from a building goes up as outside temperature drops.

9) The key to greater heat pump performance is capacity selection
(sizing).
See 1 and 3 above.

10) The most energy efficient heating or cooling system is the one
that's not
operating. Insulate and lower the set point.




On Thu, 31 Jan 2008 18:09:02 -0800 (PST), BobR
wrote:

On Jan 31, 7:46Â*pm, Bubba wrote:
On Thu, 31 Jan 2008 12:43:35 -0800 (PST), BobR





wrote:
On Jan 31, 2:23Â*pm, Bubba wrote:
On Thu, 31 Jan 2008 08:05:30 -0800 (PST), BobR

wrote:
On Jan 30, 7:34Â*pm, bill wrote:
My daughter is complaining about high heat bills. Â*i bet the elect
resistence elect coil is on a lot. Â* how do i tell when the coil comes
on? Â*and how do you turn it off? Â*what turns it on? Â*when temp is
below 32? Â* if compressor is ok, why would coil come on? Â* she had the
system checked and they said ok. Â*wonder if they checked out operation
of coils. Â* Â*thanks for any insight. Â* bill Â*in Maryland

Face it, heat pumps are the most ignorant system ever developed and
suffer from a basic design fault. Â*The lower the temperature, the less
efficient they become and nothing will help the electric bill from
skyrocketing. Â*Heat pumps are ONLY effective in the few southern
states where the temperature does NOT go below 40 degrees for any
extended length of time. Â*Below 32 degrees, they are a total joke.

Nice to know you are so fuquering stupid BobR. Get a clue and a brain
and come back when you actually know something useful.
Heat pumps work very well. Mine heats my home until about 17-18
degrees outside. Then it starts losing temperature so the back-up heat
kicks in. I'll sell you a home with straight electric heat and I'll
take the same EXACT home except I get a heat pump. We'll compare bills
each month. You'll be hurting.
Bubba

Comparing the Heatless Pump to pure electric heat might be a valid
point but comparing to Natural Gas or even propane is a damn joke.
Yes, mine also heats down to 17-18 degrees but in order to do so it
must run almost continously and the electric bill for winter heating
is double my bill for cooling in July and I live in DALLAS where it
doesn't really get all that cold but it does get that hot. Â*I have had
it checked, checked, and checked again and even the Air Conditioning
people admit that they are worthless pieces of crap.

Yes, around 20 or so outside it seems to run 24/7 or something like
that, HOWEVER........................
The next time it is that cold out, go out and wrap and amperage meter
clamp around the run or common terminal of the compressor and not the
amperage draw.
Now, wait till it is 95 outside or some sweat busting temperature like
that and measure that same wire with your amp meter.
BIG difference.
Heat pumps work if installed correctly paying careful attention to
equipment sizing and duct sizing.
No, its not as warm as gas, oil or propane but saves tremendously for
those that only have the option of electric.
Bubba- Hide quoted text -

- Show quoted text -

A heat pump using ground heat and cooling would probably be as
effective as anything available, gas or otherwise. The problem with
the heat pump and most air conditioners is the reliance on ambient air
temperatures which are totally ineffective at the time they need to be
the most effective. The colder it gets, the more you need the heat
and the less it is available. Likewise, when its super hot outside,
you can't get any cooling out of the hot air. The only really
effective method would be to bury the evaporator coils deep in the
ground where the ambient temperature will remain almost constant.

That system is now gaining acceptance in many areas and is proving
both effective and cheaper. Unfortunately, nobody in my area knows
crap about it and even if they did, the soil around here is so
unstable that it may prove ineffective.