In 2009, I wrote about the benefits of geothermal heating and cooling technology and interviewed New Palestine resident Dave Maas, who had just had a geothermal system installed at his home.
At the time, Maas liked the balanced heating and cooling he was getting from his geothermal – or ground source – unit, compared to his previous air source furnace and air conditioner, but he said it was too soon for him to determine if he was saving any money on his monthly heating and cooling bills.
I recently checked back with Maas to see if he was able to give a better assessment now that a few years have passed, and if he could tell us if a geothermal unit was right for his home.
“It looks like I’m saving probably about $75 to $80 a month over the expenses that I incurred that last year that I had the traditional system in my house,” Maas said.
Geothermal units haven’t come down in price much over the past few years. They still cost about 30 to 40 percent more upfront than a traditional furnace and air conditioner; between $20,000 and $25,000, on average. However, a federal tax credit of 30 percent of the cost of the system and the installation brings the initial cost down closer to the price of a traditional unit. Plus, the systems last about twice as long as a conventional air source unit. And then there’s the long-term payback, like that which Maas has enjoyed.
“I think people are scared because of the big numbers they cost to put in, but these things are legitimately a good investment,” said Nigel DeChristopher of Top Shelf Heating, Cooling & Geothermal in Indianapolis, which has been installing geothermal systems since 1999.
Geothermal heat pumps work via a unit in the home connected to an in-ground loop system that relies on the steady approximately 55-degree temperatures from deep in the earth, instead of outside air, to provide heating and cooling to the home. The systems use no fuel and can be three to four times more efficient than the highest-efficiency air source units.
“I like to (explain it) as if you have a furnace and air conditioner, but it’s always 55 degrees outside,” said Brad Odom with Control Tech Heating and Air Conditioning, in Zionsville, Indiana.
“It’d be pretty easy to heat and cool the home if it was always 55 degrees outside. You can look at geothermal technology as doing just that, because it’s exchanging heat in the home with a 55-degree earth temperature.”
Any homeowner considering adding a geothermal system should make sure the company first performs a Manual “J” load calculation – a room by room analysis that determines how much air is needed to keep the room’s temperature comfortable – to ensure the unit is sufficiently sized to meet home’s energy needs.
“It’s super critical with any home and any kind of system,” DeChristopher said. “That way, you know the exact amount of heating and cooling they need for the coldest and hottest parts of the year. Sizing is really important to how much geothermal can save a customer.”
Adding a geothermal system typically does involve serious excavation in the backyard, but advances in technology can help limit the damage done to yards.
“Now, you can do loops with very minimal disruption to the yard,” Odom said. “Instead of an excavator to dig up the yard, you can use a directional bore machine to drill underneath the yard. Another technology is called a hyperloop technology, where we can fit a much larger loop into a smaller space. Previously, we had to come out with an excavator and dig big trenches to put loops in.”
Not every heating and cooling company has expertise in geothermal, so be sure to research a company’s background before you hire. Maas said he’s fortunate that the same technician that installed his system is still working for the company and has been out to service the unit for a minor repair.
“You can’t just go to ‘Bill’s Heating and Air Conditioning,’ you have to go find a ‘Bill’ that really knows geothermal and knows that particular unit that you have in your house,” Maas said. “There are a couple of different manufacturers and I’m sure they’re similar, but you want to find somebody that deals primarily with the unit you have.”
Editor's note: This article was originally published in June 2012.