Save Money with Geothermal Why not utilize the free energy located just a few feet beneath the surface of your own property? A WaterFurnace geothermal system can use one unit of electrical energy to extract an remarkable five units of energy. Unsure of what that means to you? What you get is an efficient means to condition your Danville home - much less than what your friends and neighbors will pay. The geothermal products we put in your home are the most efficient equipment in the industry today. So why not use the clean, renewable energy in your backyard and get your savings up to 70% on heating, cooling, and even hot water!