This is a 3 bedroom 1800sq' chalet style home. (Its 2100sq' when calculating heat loss due to high cathedral ceilings. It is in-floor heat throughout. No air handlers and no cooling (yet). Heat source is a 3 ton water to water heat pump (Nordic by Maritime Geothermal) coupled to a ground loop of 1800' (3 - 600' loops). Also has a de-superheater for domestic hot water. The house has a lot of solar gain and quite sheltered from the north wind.