Heat Pumps

heat pump“New heat pumps for 2010 eliminate that chilly feeling and lower utility bills”
By James Dulley

Q: I hear people install a heat pump instead of a furnace and air conditioner even in cold climates. I can’t afford a geothermal one. Would a standard air heat pump work well and what are newest designs? – Mike H.

A: Heat pumps are becoming a more common alternative to central air conditioners because they can also heat your house. The cost of electricity for heating and cooling a house, although it gradually increases as do most prices over time, is much less volatile than natural gas, oil or propane. You may also get up to a $1,500 tax credit for installing a heat pump.

A geothermal heat pump is one of the most energy efficient heating and cooling systems for any climate. Even though it provides a good payback on the investment, particularly in very hot or cold climates, the initial installation costs are considerably higher than for air-source models.

An air-source heat pump is basically a central air conditioner with a few extra parts. During the summer, it draws heat from the indoor air and, through a refrigeration cycle identical to an air conditioner, expels the heat outdoors. The cooling efficiency is rated by its SEER (seasonal energy efficiency ratio).

During the winter, a reversing valve inside the outdoor condenser unit switches position. This reverses the flow of the refrigerant so it begins to draw heat from the outdoor air and transfers it so an indoor coil. Heating efficiency is rated by HSPF (heating seasonal performance factor).
There have been many recent developments in air-source heat pumps. The modulating, multistage output rotary compressor design is now available in heat pumps. This design produces extremely high efficiencies for both heating and cooling (HSPF – 10, SEER 22). You can get $2 to $3 worth of heat for each $1 on your utility bills.

This heat pump uses a rotary compressor with inverter technology to allow it to vary its heating or cooling output from about one-third to full capacity output. This not only saves electricity, but it also produces extremely good comfort, quiet operation and even room temperatures. Two-stage heat pumps also improve efficiency and comfort over standard single-stage models.

Heat pumps can be coupled with a high-efficiency gas furnace for a hybrid system in cold climates for efficiency and better comfort.