Heat pumps reliable, efficient

Dear Jim: Some neighbors with gas or oil heat just installed heat pumps. I have electric heat and I am thinking about installing a heat pump too. What is new in heat pumps and which are most efficient and comfortable? – Ray W.

Dear Ray: Heat pumps have unfairly gotten a bad reputation over the years. From both quality and comfort standpoints, new heat pumps are a reliable and efficient source of heating and cooling. I have used heat pumps for 15 years to heat and cool my own home.

If you have an electric furnace or baseboard heat, installing a heat pump can cut your utility bills by more than 50 percent. The most efficient heat pumps produce $3 of heat for each dollar on your utility bills.

With gas, propane and oil prices increasing, installing a heat pump, instead of just a central air conditioner, with your old furnace may make good economic sense. During mild fall and spring weather, a new heat pump can heat your home less expensively than a gas, propane or oil furnace.

Depending on your budget, climate and comfort needs, there are many new heat pump options. Generally, the most efficient heat pumps also provide the best heating comfort and indoor air quality. Since a heat pump is also used for cooling, you will get year-round savings and comfort improvement.

The most efficient heat pumps use compressors that produce two output levels of heating and cooling. Most of the time they run at the low-output mode and switch to high output only on very cold or hot days. At the low level, they run for longer cycles so the indoor air temperature stays more constant and air quality is better.

Most two-level heat pumps use a variable-speed blower motor in the indoor air handler. When the heat pump is running at low level, the blower motor slows down. This reduces the noise level and eliminates the gust of chilly air each time it starts.

Within just the past year, efficient two-level scroll compressors have been introduced. These have few moving parts, eliminating the need for pistons, valves, etc., so they operate quietly and reliably. They also use new ozone-friendly R410A refrigerant instead of older R-22 Freon.

Other two-level compressor designs use either two separate small compressors or ones that reverse rotation to vary the heating and cooling capacity. These have been used for many years and are a reliable technology.

If you cannot afford an expensive two-level model, select a single-level scroll compressor model which uses R410A refrigerant. This is what I use at my home. For a little extra initial cost, consider an optional variable-speed blower motor with it. Summertime cooling comfort will be particularly improved.