So, I don’t know about where you live, but here in the mid-Atlantic region we’ve been experiencing some of the highest temperatures and humidity rates in the history of the earth. Well, maybe not quite that extreme, but baby, it’s hot out there and it’s the humidity that gets ya. And yet at night I curl up with a blanket and
read War and Peace watch something ridiculous on one of the three stations of tv we get because the air conditioning is blasting trying to keep us “comfortable”. I switch between a tank-top and a sweatshirt based on whether or not the air-conditioning is running.
But there is a dramatically more efficient way to heat and cool our homes. The use of geothermal heat pumps are becoming more and more common these days, for both renovations and new construction. In fact, the renovation and addition our aunt in Massachusetts is working on spurred this post about geo-thermal heat pumps. She is looking at adding one to her smaller, Cape-style home which currently has a much too old forced air heating system and window-units for air conditioning. With the installation of a geo-thermal heat pump, she’ll get much more consistent heating and cooling throughout the year, and save between 30 and 40 percent on her heating and cooling costs.
A geo-thermal heat pump works by pulling from the earth’s constant temperatures. Think of a cave which would maintain a consistent, cooler temperature than the outside air in the summer, and be warmer than the outside air in the summer. Through a series of loops and coolants and compressors and fans, a heat pump would draw the heat out of your house in the summer and dissipate it back into the earth. In the winter, it would draw from the earth’s heat and pump it into your home. Here’s a (very simplistic) diagram that might better explain this:
There are various ways these loops can be configured underground: coiled, horizontal loops, vertical loops. The type and length used would be based on your home’s heating and cooling loads, the soil conditions, and the severity of temperatures in your area.
The cost for this type of system is generally more expensive upfront, due to the earthwork involved for the installation. The extent of drilling would depend on the type of system necessary, but most of the mechanical parts of the system are located inside the house and easily accessible for maintenance. But there is generally not much maintenance required, due to the relative simplicity of the components in the system. The underground piping used is usually guaranteed for 25-50 years. A geothermal heat pump is also quieter to operate than a typical HVAC system because there is not condenser unit outside humming away as it works. Studies show that over 95% of geothermal heat pump owners would recommend the system to others. So, for a little more money upfront, you will save money over time and probably be more satisfied with the quality of heating and cooling in your home.
You can read more about the virtues of geothermal here. As for me, it’s definitely on the wish list for a future home. I love the fact that it relies on a renewable energy source- the earth. There is also a way to equip the system to heat the water used in the house as well. During the warmer months of the summer, heat removed from the air in the house can be expelled into the loop and used to heat the water in the house. A combination of the heat-pump loop and a regular hot water tank can reduce water-heating costs by about half throughout the year. It seems much more efficient to make the most of the energy bubbling just below our feet.
So excuse me as I grab a sweater. The A/C just kicked on again and my teeth are chattering.