Is Geothermal Heat Pump HVAC Worth It?
Our furnace and air conditioner are getting a little "long in the tooth." In fact, they are original to our 1986 house. And while to my mind, the 80s were just like totally only yesterday, the harsh truth is that 24 years have gone by. We have a traditional gas burning forced-air furnace that once in a while gets plugged up with old construction debris (sucked down from the cold air returns which are only cavities in the walls) and spills water on our basement storage room floor. Other than that, it's kept on chugging along and we have our fingers crossed that it won't die anytime soon. The same goes for the A/C, which as far as I can recall has never needed a repair. (Knock on wood.)
But as time marches on we are getting closer to that day when we'll need to replace our HVAC. With that in mind, we've from time to time looked into geothermal heating and cooling systems. They are efficient and provide a "green" alternative to traditional HVAC systems. But like many green products, it can be more expensive. So if you are thinking of installing one, you ought to weigh the expenses against the return.
Geothermal systems work by using the heat stored in the surface of the earth to heat the home in cold weather, or to pull heat out of the home to cool it in warm weather. Polyethylene piping is installed under the ground or under water, and water (or antifreeze) is circulated through these pipes to either be warmed by the ground temperature (about 50 degrees) or to transfer heat from the house to the ground. A small unit in the house uses electricity to concentrate the heat and to circulate the air. More info on the operation of the geothermal heat pump is here.
As home improvements go, the geothermal HVAC system is one of your very high ticket items. Depending on what type of installation you get it may be more or less expenses. Installation types include:
Horizontal Loop - piping runs back and forth underneath your driveway or yard
Pond Loop - piping is installed under water
Vertical Loop - if you don't have the square footage available for horizontal, the alternative is to have a well driller drill a shaft into the earth for the piping to run down into
Open Loop - also involves drilling, as it uses ground water for heating and cooling
According to the Consumer Energy Center, geothermal heat pumps cost (for an "average" home) about $7500, plus the cost of installation which varies depending on the need for drilling (anywhere from $10,000 - $30,000). To reap a savings of 30-60% on your heating and cooling bill, is it worth it?
If you are planning to stay in your home for at least 5-10 years, the geothermal HVAC will probably pay for itself in energy savings. In our situation, where we are still paying off credit card bills from our kitchen remodel, it would not be cost effective to put money into a geothermal heat pump rather than paying off high-interest debts. But we are keeping our fingers crossed that the traditional HVAC we have will keep on trucking until we are able to justify the expense of a high priced heating and cooling system, and have saved up the cash to buy it.
