Unless there's a buried coolant loop, an air exchange heat pump isn't going to be anywhere near as quick to warm up a house as a furnace in northern climates.

Unless there's a buried coolant loop, an air exchange heat pump isn't going to be anywhere near as quick to warm up a house as a furnace in northern climates. Air exchange heat pumps are a stepping stone, I think. If I could get a buried loop heat pump, I'd jump on it. I need to up our insulation a bit from the 1920s era first.