Heat Pump Efficiency
People have heated and cooled their homes with heat pumps for years. When energy costs were lower and there was less concern about a healthy environment, fuel burning furnaces and air conditioners replaced heat pumps in many areas. Now, thanks to the effiency of heat pumps, consumers are taking another look.
Heat pumps operate on the simple principle of moving heat around. Most of us aren't aware that even the coldest air does hold some heat. During the cold months, the heat pump takes heat out of the cold outdoor air and sends it into the home through ducts. When the temperature rises, the pump draws the heat away from indoor air and replaces it with cold.
All heating and cooling systems possess both positive and negative aspects. Ideally we choose those with the greatest benefit to our budgets and the environment for our homes and offices. Some of the advantages of using a heat pump are:
- The air stays moist and somewhat humid rather than drying out, as can sometimes happen with conventional heaters
- Not burning fuel makes it cleaner to operate, with no fire danger
- Less expensive to run, with few repairs to worry about
- Year-round use costs less than a furnace (idle in summer) or air conditioner (idle in winter)
Because heat pumps both heat and cool air, they have two efficiency ratings. One, the Seasonal Energy Efficiency Ratio (SEER), applies to the cooling function. A high rating indicates that the unit uses less electricity to cool the same amount of air as a unit with a lower SEER.
The Heating Seasonal Performance Factor (HSPF) tracks the same information when the heat pump is in heat mode. Again, the higher the rating, the the more heat the unit generates for the same amount of input energy.
Although it costs more to purchase a highly efficient heat pump, they eventually pay for themselves in fuel savings. If a person plans to live in their home or maintain an office for a long time, they may even consider a two-stage heat pump. These models use 50% less energy when on the low setting, which usually is all the energy that is needed about 80% of the time. Furnaces and air conditioners that cycle on and off frequently create wider temperature swings, which make the units work harder and cost more to operate.