Natural Air Conditioning/heating

[Coram Deo]

I know I have heard of Geothermal, but has anybody ever heard of the following?

2 or 3 drillholes are dug around the building each 200 to 300 feet deep at a depth that underground temps. are constant 50 to 60 degrees. The holes are reinforced with culvert pipes which extend to a well room in the house about 8 feet deep. Attached to the ends of the pipes are solar powered fans to bring up the air flow from underground. The well room is filled with 1 foot of water that mixes with the cooler air flow from the culverts that causes mist that is sent throughout the house. Ergo, a very cheap source of Air conditioning that cost no more in a few solar power fans run by the sun......

As anybody heard of this? Is this possible? What would be the cost of the project, Wells dugged, etc?

It sure would save ALOT on the electric bill.....

 

[Mushroom]

Wells around here run in the neighborhood of $12-15 per foot. 3 @ 200= $7200-9000. Never heard of the system, but with solar fans may be cost efficient over time. The install of a HVAC ducted system around here w/ heat pump runs $5-7000 (including ductwork), then ya gotta pay elec. forever afterwards (well, almost anyway). Solar can be pretty expensive on the front end, then maintenance of storage batteries, etc., but sounds feasibly economical. I'm gonna check it out, sounds interesting.

 

[Coram Deo]

It does sound economical and and even in the long run..... The solar fans they were talking about were self contained solar fans which can be bought pretty cheap without getting a complete solar power system.......

Maybe we can collaborate.. Let me know what you can find out and I will do the same...

With the cost of electricity going up, and it cost so much to run ac and propane keeps going up up up with trying to heat, it would be nice to find some alternative to cut the energy bill and not have to pay the money grubbing power companies...

Wells around here run in the neighborhood of $12-15 per foot. 3 @ 200= $7200-9000. Never heard of the system, but with solar fans may be cost efficient over time. The install of a HVAC ducted system around here w/ heat pump runs $5-7000 (including ductwork), then ya gotta pay elec. forever afterwards (well, almost anyway). Solar can be pretty expensive on the front end, then maintenance of storage batteries, etc., but sounds feasibly economical. I'm gonna check it out, sounds interesting.

 

[VictorBravo]

I did something sort of similar back about 20 years ago, except that instead of drilling a well, I used a swampy spring about 100 feet from the trailer I lived in. I ran across a bunch of 8 inch pvc drain pipe for almost nothing and laid them in the swamp with the end sticking up out of the water on the far side--then ran the pipe in a small trench to the trailer where I hooked it up to a housing with a regular cheapo house fan.

It really worked. The spring/swamp stayed a steady 55-60 degrees even in the hot summer and the air coming out of the fan was around 65 degrees. It cooled that hot trailer from around 90-100 degrees in the summer down to around 80 during the day and 65 at night. Not exactly air conditioning temps, but much more comfortable.

So I'd recommend trying it if you have a source of flowing water. Digging wells is very expensive, but digging shallow trenches not so much.

 

[Coram Deo]

Interesting.....

Accept swampy places tend to be more humid and I can not have humid........ 80 plus humid = bedridden for me...

On the other hand the underground temps tend to be dryer......

Here is something, can't we just dig our wells the old fashion way by ourselves....

Another question... If the temp of 200 feet down equals 50 to 60 degrees, would the temp of 100 feet be something like 68 or 69 degrees..... Still not a bad temp to bring into the house.......

I am not sure what the ratio is for ground temp... ft. = temp... Anybody got a clue....

I did something sort of similar back about 20 years ago, except that instead of drilling a well, I used a swampy spring about 100 feet from the trailer I lived in. I ran across a bunch of 8 inch pvc drain pipe for almost nothing and laid them in the swamp with the end sticking up out of the water on the far side--then ran the pipe in a small trench to the trailer where I hooked it up to a housing with a regular cheapo house fan.

It really worked. The spring/swamp stayed a steady 55-60 degrees even in the hot summer and the air coming out of the fan was around 65 degrees. It cooled that hot trailer from around 90-100 degrees in the summer down to around 80 during the day and 65 at night. Not exactly air conditioning temps, but much more comfortable.

So I'd recommend trying it if you have a source of flowing water. Digging wells is very expensive, but digging shallow trenches not so much.

 

[Mushroom]

Another question... If the temp of 200 feet down equals 50 to 60 degrees, would the temp of 100 feet be something like 68 or 69 degrees..... Still not a bad temp to bring into the house.......

I am not sure what the ratio is for ground temp... ft. = temp... Anybody got a clue....

From a wikipedia article on geothermal heating:

The Earth below the frost line remains at a relatively constant temperature year round. This temperature equates roughly to the average annual air-temperature of the chosen location, so is usually 7-21 degrees Celsius (45-70 degrees Fahrenheit) depending on location. Because this temperature remains constant, geothermal heat pumps perform with far greater efficiency and in a far larger range of extreme temperatures than conventional air conditioners and furnaces.

So the temp. is stable below the frostline, if correct, and as I recall' I've read it to be a steady 55 degress F in the Mid-Atlantic area.

 

[Coram Deo]

Ah, So what is the frostline depth for mid-atlantic?

I live in Maryland....

Another question... If the temp of 200 feet down equals 50 to 60 degrees, would the temp of 100 feet be something like 68 or 69 degrees..... Still not a bad temp to bring into the house.......

I am not sure what the ratio is for ground temp... ft. = temp... Anybody got a clue....

From a wikipedia article on geothermal heating:

The Earth below the frost line remains at a relatively constant temperature year round. This temperature equates roughly to the average annual air-temperature of the chosen location, so is usually 7-21 degrees Celsius (45-70 degrees Fahrenheit) depending on location. Because this temperature remains constant, geothermal heat pumps perform with far greater efficiency and in a far larger range of extreme temperatures than conventional air conditioners and furnaces.

So the temp. is stable below the frostline, if correct, and as I recall' I've read it to be a steady 55 degress F in the Mid-Atlantic area.

 

[VictorBravo]

The temperature is indeed stable below the frost line, around 55 degrees. But if you are adding heat to it by passing a duct carrying warm air, it will go up.

Two key things to consider: wet (or merely damp) absorbs more heat than dry. A longer run for the heat transfer duct means less temperature fluctuation from the warm air passing through it.

My method worked with only 20 feet of contact with the wet swamp. If you want to use dry ground, more would be needed, but still a relatively shallow trench is easier than a deep well. I haven't worked out the heat transfer, but it isn't that hard to figure.

But when you get into the realm of doing this as a real system (as opposed to my jury rigged one), you really should consult with someone familiar with heat exchange coefficients for your soil, air volume requirements, and a host of other things. In other words, if you are not going to make due with duct tape and bailing wire, it can get expensive.

But, I do know this: a house with two walls embedded in a hillside takes much less fuel to heat and cool. (and basements are always cool unless heated).

BTW, any contractor, farmer, or plumber would know the frost line for your area. In Montana it was 6-8 feet. In the Puget Sound area it's around 18 inches. I bet it is somewhere around 2 feet where you live.