daestrom wrote:

...Bill Shurcliff suggests putting a window AC in a basement stairwell
with the warm side in the living space to air condition the basement and
heat the house in wintertime.

The outside half of a window AC might be a bit loud for putting in the
living space.

Agreed. Maybe it needs a sound enclosure with baffled airflow paths.

And these units aren't really meant to condition the cold side... below 55F.

True, altho some people use them for walk-in coolers, with freezestats.

But I suppose you might try reducing the air flow so the coil runs cooler.
If there's a lot of moisture, one might have problems with freeze-up though.

We might turn off the compressor with a freezestat on the cold side.

Besides, once you dry out the basement, you going to deliberately spray
water on the floor?

Maybe.

Like to see what that does for mold/mildew levels.

Maybe nothing, with a humidistat and a soaker hose and a solenoid valve from
an old washing machine to keep the RH near the floor 60%. Would that work?
Pb = 0.6e^(17.861-9621/(460+50)) = 0.220 "Hg, so wb = 0.62198/(29.921/Pb-1)
= 0.00461. Removing all that water makes 4.61 Btu per pound of air. Heating
a pound of 50 F air to 65 F takes 0.24(65-50) = 3.6. Hmmm. Maybe we need an
air-air heat exchanger. A natural molecular one, based on warm air bouyancy?
Or a 2'x2'x8' counterflow closet with lots of vertical layers of plastic film?
We might convert all the latent heat with about 5340/4.61/0.075/60 = 257 cfm.

Your scheme is just using heat at ~50F on the floor slab/ground to evaporate
water, then using a dehumidifer to condense the water putting the heat into
the living space,

We can also convert latent heat from people and their activities, about 2
gallons per day for an average family, Andersen says. And latent heat from
a greenhouse or plants in the sun. Plants in the sun can evaporate 1 lb
per day per square foot of floorspace, and moist air is a great way to move
heat out of a greenhouse without much airflow.

A far more effective method would be to use a heat pump designed for the
purpose and extract heat from the ground directly.

I just bought a $69 10.2 EER 5340 Btu/h Daewoo AC. Restricting the cold
side to lower the temp does not seem to change the COP. Restricting hot
airflow to make it 110 F dropped it to 2... 3 tons of Daewoos would cost
$69x36000/5340 = $465.

Avoids the mold/mildew...

What mold and mildew? We might AC a non-people space, eg a moldy coldframe
or mushroom house, with compost heat. Dry compost materials have the same
heat value as wood, about 10K Btu/lb. With proper care in a closed vessel,
they can lose 15% per day by weight. Horses or cows might help. With an AC,
we don't have to breathe the same air.

Only down side is total cost...

A pesky detail :-)

Nick