Difference Between a Heat Pump & Resistant Heat

When energy prices rise and your main home energy source is electricity, you may start thinking of comparing heat pumps and resistive heating. It can be complicated, because the heat pump is more economical over the long run, but it costs significantly more up front to buy and install. So any serious analysis should always include a break-even point--the point at which the higher initial cost has paid for itself in lower energy bills. Where you live and what kind of house you live in will affect the calculations.

Operational Comparison

Resistive heating such as baseboard electric heating directly converts electrical energy into heat; heat pumps use electricity to move heat from one place to another. During the summer, your air conditioner (a kind of heat pump) moves heat from indoors to out. During the winter, the cycle is reversed, and the heat is moved from outside to inside. It's sort of as if you turned your window air conditioner around during the winter.

Efficiency Comparison

Electricity converts to heat with almost complete efficiency. Yet overall, heat pumps are 3 to 4 times more efficient per watt of electricity because they merely move heat instead of creating it. The catch with heat pumps is that they only work efficiently down to a certain difference between inside and outside temperatures. So air-source heat pumps are mainly restricted to places with mild winters such as the Southeast U.S.

Ironic Combination

A centralized heat pump often includes a small resistive heating system for winter. When it's mild outside, above 40 degrees, the heat pump is more efficient. If the temperature drops, the system adds some resistive heating to augment the heat pump.

Efficient Variations

Geothermal heat pump systems take advantage of groundwater that may stay 60 to 65 degrees F year-round. This system pumps water up from a relatively shallow well, extracts the heat, and returns the water to the ground. You can also get small, inexpensive resistive heaters to heat small spaces such as a single bedroom or bathroom, instead of your entire house.

Calculating Benefits

Your electric utility company can probably send you an information package on how to calculate the economic benefits of each type of home heating, and how to size them correctly to your particular needs.