Geothermal systems work with nature, not against it. They emit no greenhouse gases, which have been linked to global warming, acid rain and other environmental hazards. WaterFurnace provides an earth-loop antifreeze which will not harm the environment in the unlikely event of a leak. And much of the WaterFurnace product line uses R-410A, a performance-enhancing refrigerant that will not harm the earth's ozone layer.