Dear Angie: We need a new HVAC unit. Should we look into what might be out there that could be better for the environment and for our health? – Shelia K., Indianapolis

Dear Shelia: A geothermal system might be right for you. These units don't draw air from outside like traditional HVAC units, so allergens such as pollen won't be sucked into your home. Geothermal heat pumps use heat from the ground to warm or cool your house. Many geothermal heat pumps are Energy Star-rated, which means they use less energy than other units and may qualify for a tax credit.

Geothermal units are more expensive than other HVAC systems, but they are also far more efficient than even the best natural gas furnaces. They require no fuel, produce clean energy with few carbon emissions and are 30 percent more efficient than conventional HVAC systems. They can save you hundreds of dollars on your energy bill every year.

Geothermal units utilize a loop system, in which a loop of piping is buried underground and brings heat from the earth into the home during the winter and pulls heat from the home back into the earth during the summer. Not every heating and cooling company installs geothermal units, so it’s important to do your research before you hire. Loop installers are certified by the International Ground Source Heat Pump Association.

Energy Star ratings are also available on conventional HVAC systems, and you’ll realize energy savings from these units, as well. You’ll be helping the environment by upgrading an outdated system with one certified as Energy Star regardless of how it’s fueled.