Why do most people seem so confused and bewildered about heat pumps? They have been around now for at least several decades, yet the technology behind them seems to mystify so many people. So, I decided to research this subject for myself in order to tell you how - in layman's terms - these things work

The first thing I should deal with, I guess, is the name itself: heat pumps. Why are they called that? If they are pumps, then what are they 'pumping?' Well, the word pump is actually very appropriate (at least to my mind), as pumps move something - water, gas, oil - from one place (like the bottom of a well) to another place (like your sink). And that's exactly what heat pumps do: they move, or 'pump' heat energy. If this is a hard concept for you to grasp, here's an illustration. Imagine letting a cup of hot tea sit awhile to cool down. Now think about it: What really happened? Well, when a hot liquid cools, the heat energy passes from the hot liquid to the air surrounding it. In other words, heat was 'pumped' (moved) from one location to another.

You might not realize it, but even on the coldest day outside, the air contains some heat energy. The same is true for the ground beneath our feet: it has the capacity to store, or hold, heat energy. Heat pumps simply move, or 'pump' heat energy from one place to another. When you use a heat pump to heat or cool a room, you are making use of this basic fact of physics.

So let's see a heat pump at work: you have a heat pump installed. It's summertime, and your room is hot. A heat pump will circulate the air in the room, draw off some of the heat energy and transfer that heat energy outside. Because heat energy has been taken out from the room, you feel cooler.

In the wintertime you simply reverse the process - you use your heat pump to move heat energy from the great outdoors to your cold rooms inside (remember what I told you: even in the dead of winter heat energy can be captured from the outside air). You will begin to feel warmer in that room as a result.

It's important to note that heat pumps, by themselves, do not actually use fuel to add heat energy to a room - they simply move it from place to place. This makes any heat pump different from a traditional furnace. Furnaces heat a room by burning fuel (gas, oil, electric) to add the necessary heat, whereas a heat pump simply gets it from another location.

Some heat pumps, called air-source heat pumps, capture heat (for heating) from the surrounding air. To cool, they simply draw it off and expel it into the air. They may draw heat energy directly from the air that surrounds the heating unit, or they might have a separate unit outside that captures and funnels the heat energy to the inside unit for dispersion throughout your home.

Other types of heat pumps are called Geothermal heat pumps - they draw heat energy from the ground outside (below the frost line) to heat, or pump excess heat energy into the ground to cool. They do this by transferring heat energy through a series of coils that are buried deep in the ground. You may not realize it but below a certain depth the temperature of the ground remains fairly constant year-round.