Heat Pumps

So you think you want to install an air source heat pump in your home as a contribution to reduce global warming. Well you may help in the prevention of global warming but depending upon where you live you may be giving up personal comfort. Having lived in areas where heat pumps are common I can assure you that they are a poor source of heat and do little to prevent global warming. Air source heat pumps are the most common type of home heat pump because they are the easiest and least expensive to install. Essentially a home air source heat pump is nothing more than an air conditioner working in reverse, thanks to a device known as a reversing valve. The system consists of two sections, an outdoor section consisting of a compressor, a coil, a fan and a reversing valve and an inside section that consists of a fan, indoor coil, and a supplemental heating element, usually electric coils. Tubing containing a liquid refrigerant and electrical circuits connects the two units together.

When the heat pump is in heating mode, the liquid refrigerant literally takes warmth out of the outside air, if there is any, and carries it to the indoor coil where the blower moves filtered indoor air over the coil and out into your home. When in cooling mode, the unit operates similar to a central air conditioner. The warm air passes over the indoor coil and gives up its heat, which the refrigerant carries outside to be dissipated by the outdoor fan as it passes through the outdoor coil.

When the outside air temperature is below 35 – 40 degrees there isn't enough heat in the outside air to provide sufficient heat for your home. Frequently the outside components frost up during cold weather rendering the system inoperative until the temperature gets warm enough to thaw it out. Because the air heat pump system is so limited at providing adequate heat it is necessary for a supplement heating element, usually electric coils. They automatically turn on to provide the heat needed to make your home comfortable in really cold weather. As a result your heating cost goes through the roof. Rather than an air source heat pump for home heating and cooling a ground source, geothermal, heat pumps is an alternative. Geothermal heat pumps use the earth or underground water as either the source of heat when warming your home or as a heat sink when cooling your home.

The geothermal systems consist of a series of pipes buried beneath the ground. During heating, an ethanol solution is circulated through pipes as a heating conductor. It picks up heat from the ground or water and carries it back into your home. Since the ground below the frost line remains at a relatively constant temperature all year round 60 to 70 degrees depending upon where you live, it provides a better source of heat in low outside temperatures. The ethanol solution runs through an air handler that consists of a coil, a blower/fan and an air filter where it give up its heat to the air moving across the coil. The blower distributes the heat directly through your home's existing air distribution system. A geothermal heat pump uses less energy and electricity to operate and doesn’t usually require an alternative heat source as an air source heat pump does in really cold weather.

The climate in your location will be is a major factor on whether a heat pump will actually work for you and produce sufficient heat for your home. If you live in an area where there are dramatic swings in temperatures, below zero, a heat pump alone won't be able to heat your home because there isn't enough heat in the outside air or ground to heat your home. You will require some form of supplemental heat. Unless you live in an area where climate is very warm most of the year and outside temperatures do not fall below 40 degrees, you will be better off using either natural gas or an oil heating system.  Natural gas and oil is substantially more efficient and less expensive than electricity. You should evaluate and compare the costs of a natural gas and oil heating system versus a heat pump.