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jeff5may · 10-01-14, 03:22 PM

Do something like Jerry did:

DIY Geothermal Heat Pump + PV System - No Heat Bills!

In your situation, no ground loop would be needed, since you already have a well. Also, you could run a water to air heat exchanger straight off the water source if the humidity is low enough, saving loads of electricity. If humidity became a problem, the water source heat pump could dry the already tempered air in no time flat.

Let me explain that one here. Lets say your home is 80 degF at 55% relative humidity and your ground source water is 59 degF. That's a 21 degF delta T. Run both through a water/air hx, and out comes cooler air at higher r.h. and warmer water. As the air is cooled, some of the heat transfer can be measured by the temperature drop (sensible heat), but usually a lot of the heat transferred is from the condensation of water vapor from the air stream (latent). The air exiting the hx will be some temp above the water entering the hx at high relative humidity. Sometimes it is near saturated.

As the indoor temperature drops, so does your delta T. When the two temps become close, less and less moisture is pulled from the air as it passes through the hx, while the exit air temp goes closer and closer to your entering water temp. The house ends up feeling clammy due to the high relative humidity, much like a root cellar or cave.

Since you already have a "conventional" air conditioner, it can be run periodically to dehumidify the cool wet air. Since the evaporator hx usually sources refrigerant temp not far above freezing, it can draw the extra humidity out of the air that is beyond the capability of the ground source water.

To save even more energy, you could run a "desiccant waterfall":

10-01-14, 03:22 PM	#12
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Do something like Jerry did: DIY Geothermal Heat Pump + PV System - No Heat Bills! In your situation, no ground loop would be needed, since you already have a well. Also, you could run a water to air heat exchanger straight off the water source if the humidity is low enough, saving loads of electricity. If humidity became a problem, the water source heat pump could dry the already tempered air in no time flat. Let me explain that one here. Lets say your home is 80 degF at 55% relative humidity and your ground source water is 59 degF. That's a 21 degF delta T. Run both through a water/air hx, and out comes cooler air at higher r.h. and warmer water. As the air is cooled, some of the heat transfer can be measured by the temperature drop (sensible heat), but usually a lot of the heat transferred is from the condensation of water vapor from the air stream (latent). The air exiting the hx will be some temp above the water entering the hx at high relative humidity. Sometimes it is near saturated. As the indoor temperature drops, so does your delta T. When the two temps become close, less and less moisture is pulled from the air as it passes through the hx, while the exit air temp goes closer and closer to your entering water temp. The house ends up feeling clammy due to the high relative humidity, much like a root cellar or cave. Since you already have a "conventional" air conditioner, it can be run periodically to dehumidify the cool wet air. Since the evaporator hx usually sources refrigerant temp not far above freezing, it can draw the extra humidity out of the air that is beyond the capability of the ground source water. To save even more energy, you could run a "desiccant waterfall": Last edited by jeff5may; 10-01-14 at 07:59 PM..