Geothermal heating

[Rusty]

Originally Posted by jeffk

I accept what you are saying but speaking as as an engineer it doesn't make any sense that units would loose efficiency in the cold unless the ground water temperature is cooled so much in the well that it can't recover quickly enough? Either that or it's a sizing problem. Even a well insulated house loses heat and it may have been a choice to increase the tonnage, at significant additional cost, to cope with the coldest weather or cheaper to put in secondary heat to deal with it.

Mostly just curious about why this would be a problem.

I am also speaking as an engineer and I don't understand it either.