Geothermal-enabled subdivision in Austin TX

[Terrel L. Shields]

lot higher than a regular heat pump.

But they work better than solar or a regular heat pump.
In the Ozarks, the ground temperatures tend to be about 55 degrees. And that applies for a couple hundred feet below ground. Since the soils here are often thin, a horizontal system is often not a great choice. Vertical holes are far more insulated from temperature changes.

Open end systems where water is extracted from a semi-deep well and returned to a nearby well can often work very well indeed. Once you get below 1,000' or so in the Ozarks, the geothermal gradient increases and water temperatures are higher. In oil well country like W. OK or W. Texas, bottom hole temperatures can be quite high. I have worked on wells where the mud would get so hot it was uncomfortable and in the Rockies, I have been on wells where the drilling mud was no warmer than the air temperature in summer. But in other areas the bottom hole temperatures were very high - 200-300 degrees F.

 

[George Hatch]

Soil composition is a factor, and so is altitude. Average temps vary by latitude

 

[George Hatch]

Idylwild, CA and Palm Springs are at almost the same latitude but at different elevations. Idylwild has a 36* split between the highs and lows today, and is 15* cooler than Palm Springs. Moreno Valley (40 mi west of palm springs) splits the difference. The corresponding ground temps will be different.

 

[sputnam]

If they can get Texas temperatures from 115 degrees to say 70-80 in the summer, maybe I will consider moving there. Otherwise, I'm staying put.

But wait a minute, don't heat pumps work by exchanging temperature? How is pumping heat out of the earth to the atmosphere going to cool Texas? Something doesn't sound right. OK. Wait. You mean its going to cool the insides of homes, although make the outdoor temperature hotter. That sounds like a positive feedback loop.

The heat exchanger is in the ground... rather than using the air. It's very effecient, since at the right depth (different depending on where you live) the ground stays the same temperature all year.