Comparing geothermal to ultra high efficiency conventional
I'm going through the exercise of comparing geothermal to conventional. Here are the details:
Location: Northern Virginia
Propane rate: $2.55/gallon
Electric rate: $.115 per kilowatt hour
Geothermal: After rebates/tax credits, the geothermal system is about $23,000 installed for two WaterFurnace 3 ton two-stage units with electric auxiliary heaters. One unit includes a desuperheater to help with hot water.
Conventional: The conventional units are Carrier Infinity 20 Seer heat pumps with a 95% efficiency propane furnace for auxiliary heat. Installed price after rebates is about $17,000.
To my amazement, there's no place online where I can compare the payback of these two systems. Conventional wisdom suggests the geothermal system is the way to go. But my HVAC guy is saying the conventional system will be just as efficient for $6K less. Thoughts?