The connections are all buried now. When coming up through the floor they cut the basement concrete of about a 3x3 foot area in which they came up through. Then the filled it back in with cement.

I don't think air temperaure would be as important as ground temperature in determung the lower limit. As long as there is sufficient heat in the ground and the system is sized proprrly it should have no problems in climates where humans live.

The drill head is controlled at the machine next to the hole. It is the same as drilling a well. They have extra tubes that attach as the drill moves forward (or down).

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD