It’s too soon to know how much he’ll save on his monthly energy bills, but Dave Maas has been pleased so far with his home’s new geothermal heating and cooling system.

“It seems to have heated the house on cold days and seems be cooling our house much better than our old system on warm days,” said Maas, New Palestine.

Geothermal units tap into energy that comes from heat sources deep in the earth, eliminating the need for fuel to heat or cool a home. The units use a loop system in which piping is buried underground and brings heat from the earth into the home during the winter. In the summer, it does the reverse and draws heat from the home back into the earth.

“The only downside I’ve experienced with the system had to do with the fact they had to tear up my backyard in order to put the loop in,” Maas said.

Geothermal units actually produce more energy than it takes to operate them. It’s clean energy with few carbon emissions, and delivers up to $5 of energy for every $1 used. That translates into an efficiency rating of 500 percent. By comparison, the best gas furnaces are about 95 percent efficient.

Maas began researching heating, ventilation and air-conditioning systems after deciding it was time to replace his 23-year-old furnace and air conditioner.

Geothermal systems cost more than traditional systems — Maas estimates he spent about $15,000 for his. But homeowners can recoup 30 percent of a unit’s cost through an energy federal tax credit. Lower energy bills also mean year-round savings.

“It made the number come out a lot closer between a traditional heat pump furnace system and a geothermal system,” Maas said of the savings. “I thought for the long run, the geothermal made more sense for me, so I went ahead and paid the higher price — with the understanding that next year I’ll get the tax credit applied to my tax return.”

The U.S. Department of Energy says 43 percent of the typical homeowner’s energy bill goes toward heating and cooling. Geothermal heat pumps are highly efficient and cost little to operate.

The U.S. Environmental Protection Agency estimates homeowners with geothermal systems can save 30 percent to 70 percent on heating and 20 percent to 50 percent on cooling costs over conventional systems.

Not every heating and cooling company installs geothermal units, so it’s important for homeowners to do their research before making a purchase. Loop installers are certified by the International Ground Source Heat Pump Association.

Industry experts estimate that geothermal units, which also heat water in homes, will average twice the lifespan of traditional heating and cooling units.

The units are self-contained, so there is no separate air-conditioner, and they operate more quietly than conventional units.

“It’s considered green technology,” said Rusty Burch, owner of Plainfield-based Total Comfort Solutions. “It’s really a super quiet operation. You can hardly hear it running.”