"Jake" wrote in message
news:VNuSd.15105$g44.614@attbi_s54...
When I was at my neighbor's diagnosing an (unrelated) electrical
problem, I discovered his HP can maintain 67F indoors with 17F outdoors
with the outdoor unit fan not running (burnt out).

That's rough :-) The outdoor fan is how the HP accumualtes
heat to be moved inside ...... without it - you got squat.

His COP can't be
that great in that situation, certainly not as high as 2. It was
installed in 1978, oil backup. He's on his 2nd tank of oil since
installation.

Tell him to invest in a fixed fan :-)


Ok, Paul, you got me here. I thought I understood heat pumps but what's
this about 'accumulates' heat. I guess I always thought when the RV kicked
in, the evap was being used as a condenser and the vice versa. If this not
true?... except that the metering device is still on the ID coil.

FWIW, here in Indiana I see very few people with commercial HP's who are
happy with them. Our office has them and I'm not happy with them there.
Seems like they run far too hard, and the service life is about 10 years
tops (Carrier) and the strips run a lot of the time anyhow.

Might have just been a bad application for me... overhead doors opening
and closing, pedestrian doors opening and closing, etc. I'm convinced in a
good, tight home it may be a good idea here, but in commercial, I'm
skeptical. We have Carrier here at home NG with straight AC, and it works
well.

Jake


You know, I'll bet your commercial application would work better if your
building had more "thermal mass" to store the heat so that the temps would
be less affected by doors opening, etc. More mass might help keep the
strips from coming on as often (or as long).