Heat Exchangers

[Mortblanc]

I failed to notice this thread when it was fresh.

I have lived with a "heat pump", as we call them over here, for a 5 year period.

It was installed as new construction in a house fully insulated with triple glazed windows, sealed doors, the works.

The one main feature no one talks about when selling these systems is that the removal of heat from the outside air and exchange for inside air only allows the system to heat up one degree F per hour when at full efficiency.

If the outside temp is dropping at 10 degrees per hour you will be at a deficit until the system catches up, perhaps ten or twelve hours latter. In my area it is not unusual for the temp variation from day to night to be as much as 20C.

If you look at the thermostat and see that it is two or three degrees too cool, and move the setting, it will take the system half the day to reach your desired temp.

Fuel efficiency was very good with the system and it cost little to run, my utility bills were half of what I considered "normal". But you were always cold, or hot, or going one way or the other. The only way to beat your own system was with a small electric heater moved with you from room to room.

These systems would be great in a simi-tropical setting, such as we have over here in our southern tier of states from Georgia and Florida over to southern Texas where low temps are in the ten C range and highs are in the mid 20C range with slow variations during winter.

They just don't work for areas that maintain temps below freezing or bouncing up and down between zero C and -20C for long parts of the year.