[FONT=Arial][size=2] I have a Mr. slim heat pump and it does most of the heating and all of the cooling for our home .
I was talking to a geothermal guy about increasing the efficiency and also having it work in real cold weather .
I think the heat pump quits at -13 °C or 10°F .
I talked about putting in BIG O to feed the unit .
He loved my idea and even offered to help for a much reduced rate as he like me loves to think out side the bubble .
He told me of a winery who has a 14 inch pipe I think buried to bring air into their wine storage 500 feet I think and the temp from summer to winter is only two ° different Cost to run this is extremely cheap.
He recommended 75 feet of 2 …6 inch big O ( 3 might be better )down about 4 + feet and he said try and keep them about 7 inches apart .
He said Clay is the best to cover them with Never gravel or sand .
I mentioned in line duct fans and he said pushing air is far more efficient then pulling .
I said I was going to feed the ducts from under my Deck as it is cooler in the summer and warmer in the winter .
I stated I was thinking of bringing the pipes up in a Insulated pipe to the heat pump from down 4 feet . He liked that and suggested a XXX to turn the duct fans on after the heat pump fan started .
His best guess was my efficiency could go up over 40+% both summer and winter .
In my area the soil temp is about 55°F ~ all year at 4 feet .
Any thoughts good or bad appreciated.
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