H LV <hveeder...@gmail.com> wrote: > When temperatures fall to 25 to 30 degrees, a heat pump loses its spot as >> the most efficient heating option for an Atlanta home. >> >> > Apparently heat pumps have improved a lot over the last decade. This > article says they now work well down to -10F or lower. >
I looked at one recently, to replace one of our furnaces. (We have one heat pump and two furnaces, for reasons beyond the scope of the discussion.) The ones they sell in Atlanta still cut out below 40 deg F. However, a Canadian correspondent tells me the ones in Canada use a geothermal heat sink rather than air. That makes sense. I saw one like that in Connecticut. If you could tie into underground water or a lake, you could use one in Antarctica, I suppose. Geothermal heat pumps and air conditioners are a lot quieter than air. This article describes geothermal heat pumps. It says they are expensive. I guess the other super-efficient ones are also more expensive which is why they are not recommended in Atlanta. We seldom have days below 40 deg F.
