I agree, which is why I stated "without aux heat". I realy like to use outdoor stats to stage the strips in the airhandler to stage with the o.d. temps, makes for maximum efficiency.
Originally posted by docholiday
Yes, but, below the balance point you only have to suppliment the difference in load and capacity. Many people, including technicians dont grasp this concept. The heat pump will still be running and producing heat. (or moving it rather).
For instance say the heating requirements are 38,000 btuhs at 15 degrees outside to maintain 70 in the house. The heat pump (depending on size, etc.)Lets call it a 3 ton, will produce say a reduced 17,000 btuhs. This means the heat pump will continue to run and the suplimental heat will only need to make up the 21,000 differnce. Not the entire 38,000 required.
Many places get cold, no doubt about it, some just plain miserable, but short of the extreme north in the US, very few places stay at or below the balance point for long. I submit that you would have to be below 20 continuosly and have no spring or fall heating requirement to make a heat pump cost more than gas.