Did you know you can extract heat from chilly outside air and use it to
heat your house? This feat is performed by the magic of a heat pump--an
appliance that uses refrigeration technology rather than fuel combustion
to provide warmth and cooling.
Whether or not a heat pump will save you money on energy bills depends on
a number of factors, including the type of fuel prevalent in your area,
your climate, and the amount of insulation and other energy-efficient features
built into your home.
According to Richard Jarvis, Technical Specialist with the National Appropriate
Technology Assistance Service (NATAS), "If you have natural gas available,
it probably makes sense for you to use it for heating and cooling with a
conventional air-conditioning system." Natural gas is a more efficient,
less expensive fuel than electricity, needed for heat pumps.
But in the Northeast or other regions where fuel-oil or resistance-electrical
heat is more the norm, a heat pump can realize substantial savings. Although
electrical-resistance heating is much less expensive to install than a heat
pump, the heat pump can deliver 1 1/2 to 2 1/2 times more heat with the
same amount of energy, depending on climate, the house, and the particular
system.
Heat pumps are most effective at saving energy when in the heating mode.
The problem with an air-source heat pump in a cold climate, however, is
that your household needs more heat as the temperature outside goes down--
but the heat pump works less efficiently at lower outdoor temperatures.
Below a temperature known as the "balance point," normally from
30 to 45º F, supplementary heat is required--and that means expensive
electrical-resistance heating kicks in.
The right way to decide the most appropriate form of heating and cooling
for your home is to do an economic analysis, based on a system's purchase
cost and efficiency, the cost of your fuel and your home's heating/cooling
load requirements. NATAS has a toll-free number to offer this type of assistance:
1-800-428-2525 (in Montana, 1-800-428-1718). Request their "Energy
Cost Index Chart" and "Life Cycle Cost Analysis" brochure.
--Don Vandervort
