Q. Does it make sense to replace my old heat pump, even though it still works, with a new super-efficient model. I would like one that is less noisy and provides better warmth. How much will I save? — W.H.
A. Replacing your old heat pump with a new quiet model can lower your heating and air-conditioning costs by 30 to 40 percent. Some super-efficient heat pumps can produce up to $3 worth of heat for each $1 on your utility bills.
If you now have a gas furnace, installing a new heat pump in place of an old central air conditioner can lower year-round utility bills. In mild weather, an electric heat pump can heat cheaper than an old gas furnace.
For highest efficiency and best comfort, install a two or three-level heat pump. A two-level heat pump uses a two-speed compressor to vary the heat output. It runs in the efficient and quiet low-speed mode most of the time.
This not only saves electricity, but it makes each run cycle longer to produce constant room temperatures. During severely cold or hot weather, it automatically switches to the high-speed mode for maximum output.
Three-level heat pumps use two compressors — one small and one medium-size. In mild weather, only the small compressor runs. In moderate weather, the medium-size one runs. In very cold (or hot) weather, both compressors run. If the house still is too cool, backup resistant heaters come on.
Two and three-level heat pumps use special variable-speed blower motors, just like in the new gas furnaces. These efficient blower motors improve comfort and can save an additional $300 of electricity each year.
The most efficient single-level heat pumps use a scroll compressor. Scroll compressors have few moving parts. Without the pistons and hardware of standard compressors, scroll compressors are much quieter.
To compare heat pump efficiencies, use the Heating Season Performance Factor (HSPF) for heating, and Seasonal Energy Efficiency Ratio (SEER) for cooling. Also consider the compressor type and number of heat output levels.
If natural gas is available, consider a new gas heat pump. It is the most efficient heating (more than 100 percent) and cooling unit available and provides the greatest comfort. It blows out air that actually feels hot.
Write for Update Bulletin 515 showing a buyer’s guide of 15 super-efficient electric and gas heat pumps listing HSPF and SEER, heat and cooling output capacities, compressor types, levels, and speeds and an annual savings payback chart. Please include $2 and a business-size SASE. Send to James Dulley, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.