I recently had a geothermal system installed in my home, in Southwestern New York. The install was completed about 3 weeks ago. It is a 4 ton Climatemaster with, 2250 feet of 3/4" line buried horizontally at least 7 feet deep It is up to 9 feet deep in other parts of the field. My desuperheater has not been hooked up yet but that should be taking place in the next few weeks. It also has the electric resistance backup installed and there is some kind of antifreeze in the lines. The system works really well, the house is way warmer than it has ever been. The EWT is about 41 and the LWT is 37 or 38. The system runs in stage one pretty much all the time. My question is this, say there was a terrible cold snap of below zero for and extended period and the EWT got down to like 20 and the LWT got down to like 15. Would the loop field recover from that during the winter? Or would it have to wait until the springtime to recover?

It should partially recover after such a cold snap ends. Loop field temps trend downward until very late winter with peaks and valleys superimposed on the trend line.

I believe your weather has been mild, so your loop temps are quite favorable for your location and the time of year, although that may have much to do with just 3 weeks operation. Those depths are good, conducive to good system performance. I can't comment on the footage per ton ratio since I don't know your soil type. I don't do horizontals - they aren't well suited to Florida.

Also bear in mind horizontal loops may take a year or two to achieve complete consolidation, that is, for the soil, helped by rainwater, to collapse all the little air voids around the tubes.

Welcome, good luck, and keep us advised as to system performance and cost of operation.

The ground on the one end had a lot of clay and large rocks, the opposite end had shale and red dirt. We put down a bit of sand to ensure that the shale would not damage the pipe. I am considering adding 1-4 feet of fill over the entire field to bring it up to grade. The field slopes terrible from right to left. I would like to make it a nice field for the kids to play soccer or football on. Would it hurt anything to add 80-100 truck loads of fill on top of the existing field?

Posted By johnny1720 on 28 Feb 2012 09:49 PM
... Would it hurt anything to add 80-100 truck loads of fill on top of the existing field?

Not at all, plus having more cover will be a benefit to your loop

The deeper the better, but the savings will never pay for all that fill. Do it for the children...

If you ever have 15* LWT, your loop design would be less than marginal.

If the EWT is still 41 F after 3 weeks of running you should be fine and your loop is working well. It will never drop down to 20F. Even after a cold snap it might drop 1-2 degrees, but it will recover. You will see. Here is an example of a 4 ton in the 3rd heating season, and the last graph on the bottom shows the EWT over a year. You cans see that it does not fluctuate much, but continues to pull heat out of the ground until the end of the heating season. http://welserver.com/WEL0448/

Posted By engineer on 29 Feb 2012 07:17 AM
The deeper the better, but the savings will never pay for all that fill. Do it for the children...

The fill is no charge, I really just want to level up the field for soccer/football.

Free is good !!!

Indeed!