Personally I think it will work ,as a HVAC Contractor with 35 years
experience and just as many working/installing Heat Pump systems, here's
my opinion, First they make a air source heat pump using a 12000 btu air
source heat pump to heat hot water, Rheem is one brand, shows it can be
installed in basement.So if you have a small unit say a 18000 or 24000 BTU
and it clearly works for the Rheem domestic hot water heater why would it
not work for a slightly larger unit. Also if you did install the outdoor
unit in the basement and have the duct work in the basement ,put in couple
a three supply registers to dump warm air into the basement with a small
return in the return duct in the basement, if it still does not work try
rejecting the discharged air (using duct ) to a casement window sending
the air outside.
You got here the Dilbert way. Study up "usenet", f*ck the
homeclonershub and come join us the "real" way. Using the
homeownersclub has a habit of making smart people look stupid. Not your
fault, just a mistake. Use usenet.
On Sat, 05 Mar 2011 22:52:57 +0000, mencarj wrote:
Look at how a heat pump or AC works (heat pump is AC in reverse). One coil
gets hot and the other gets cold. If you want a 20 degree rise in temp
upstairs you will get a 20 degree drop in the basement. That is assuming
100% efficiency. Eventually the basement will have to get as cold as the
outside or colder in order to get a sufficient heat rise in your living
space. At about 35 degrees or so a heat pump does not work very efficiently
and needs extra heat.
And as well that's assuming the same volume of heated space as compared
to the basement (which may be reasonably close for a ranch style w/ a
full unfinished basement, but for anything w/ partially finished
basement or larger heated area in comparison, the ratio would be <1:1 by
that ratio of volumes.
It's a worthless idea; there's not even remotely close to the required
heat source/sink heat capacity available; the water heater idea works
only owing to it being a much lower demand in comparison to space heat.
On Mar 5, 5:52 pm, mencarj_at_yahoo_dot email@example.com (mencarj) wrote:
So, with 35 years of HVAC experience, one of your solutions is to put
3 supply registers in the basement along with the heat pump? One of
the stupidist things posted here in a long time. Why not put a
on the roof of your car to generate electric to power the car. We
all drive for free.
The heat pump in basement idea is interesting, but would not work
unless you had some way to increase the surface area for heat transfer.
For example, if you had buried a network of pipes in the floor before
pouring the cement, you could circulate water through there, and then
have it go through a radiator. Behind the radiator you could have a
squirrel cage/centrifugal blower. Your only cost to maintain the air
temp in the basement would be for an efficient water pump and efficient
squirrel cage blower. This could make a heat pump very efficient.
Of course, if you have that setup, it would be much better to simply
use a heat pump designed to directly work with the water or whatever
fluid is in the pipes. That would be a geothermal system.
It's an interesting idea to use the basement as a heat source. But
you point out, the real question is how
much the basement temperature will drop. Dropping that temperature
is going to take some heat away from the house through colder floors,
more heat loss through basement ducts, etc.
And another big issue I see is summer. Almost all heat pumps also
serves as AC. So, in the summer, you're raising the basement
temperature and again, how much is the key question. That would
obviously depend on the size of the basement. Large, open, full
basement would be the best case. Even then, I think it's highly
I live in a smallish older townhome near Washington DC. There are 4
connected units so that the total basement (part basement but mostly crawl
space) is about 8700 cubic feet. The basement is about half underground and
there are no divisions between the units. The above ground area has some
kind of foam type insulation. It is cement floored with concrete block walls
and a cement ceiling. The basement is not heated or cooled but the water
pipes have not frozen in the 12 years I have been here and I have never
heard anyone complain that their pipes freeze. There is also a radon system
in the basement because of a mild radon problem (less than 10 pci)
The area that I want to heat and cool is about 17000 cubic feet. The primary
heat source for about half that area would be radiant floor heating.
The basement is not and cannot be used for anything except water heaters,
water pipes and telephone utilities.
Under those circumstances would putting a heat pump or two heat pumps in the
basement make sense? I would like to do it for aesthetic reasons primarily,
but also because it seems to me that even if the heat pumps cool the
basement in the winter or heat it in the summer it doesnt matter since the
space cant be used, and because of the large volume of basement space, the
air going to the heat exchanger would at least be somewhat warmer than the
exterior air in winter and cooler in the summer). My only concern would be
if somehow the heat pumps could make the area go below freezing. Also,
during the summer, there could be some condensate which would have to be
I'm not a heating specialist, but I can figure out that there's not
enough of a heat sink in the basement air to accomplish anything.
Heat pumps are done with long lengths of tubing underground because of
the huge thermal mass of the ground.
Thanks for your responses. However, i still dont understand why a heat pump
won't work. The heat pump we currently have is outside and it functions fine
until it gets really cold. So I would think that putting it in the basement
with a large air volume would mean that it would function just as well, and that
perhaps there would be a slight efficiency gain on very cold and windy days or
on very hot days since the basement is sheltered from the wind and snow and
shaded from the sun. My situation is
unusual because first in proportion to the size of the house, the basement is
very large, and second, the basement cannot be used except to run pipes and keep
the water heaters for the 4 units. I would like to put the pumps there because
they are ugly and that will get them out of my yard.
If the heat pump worked just as well in the basement as outside, i would be
quite satisfied. Is there some reason why this would not be true?
Is there any danger to the occupants in putting the pumps in the basement? If
the temperature outside went down to say 10 degrees F on the coldest day of the
year, would pipes in the basement freeze because of the heat pump?
I'll say it this way: Heat pumps can only move heat (BTUs) around. Located
outside, your heat pump can exchange an infinite number of BTUs from the air
since it just grabs "new" air with a new supply of BTUs with its fan as
needed. So, it will work whether the outside air is warm or cold pushing the
BTUs in or out of the outside air (and your house). If you put the heat
pump in your basement, the BTUs the heat pump can grab are limited by what
the walls, floor and other materials contain or can transfer in/out. Since
the BTUs can't easily flow in or out of the basement volume of air, walls
and concrete, the heat transfer is not limited by the pump but by its source
On a hot or cold day when your heat pump is trying to cool or heat your
house, it will run out of BTUs that can be pulled or pushed into your
basement. It then loses efficiency and will just run without doing any
heating or cooling. Meanwhile, your basement will either be way too hot or
way too cold. You may not care what the temperature of the basement is, but
your pipes could freeze on a cold day outdoors as the heat pump sucks heat
from the basement to put into the house. On a warm day outside, the heat
build up in the basement could be dangerous and damage wiring or the house
structure. Or, the heat could simply make the heat pump so inefficient, it
wouldn't cool the house; it would just waste electricity.
If you could fill your basement with water which has a much higher BTU
capacity per unit volume than air and concrete and use that water for your
heat pump, you might make your idea work; but there's also a good chance
that you would have a block of ice in the basement for much of the winter
and a pool of steaming water for much of the summer.
A neighbor of mine installed a ground water heat pump to heat and cool his
house. For a house of about 2500 square feet and well insulated, it takes
the water from 5 wells to supply enough BTUs winter and summer to keep the
house comfortable. It's very energy efficient because the high volume of
well water, either coming or going is always about 50 degrees F +/- 10
degrees., so it can either give or take plenty of BTUs, but drilling the
wells was expensive.
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