I have a 2900 sq ft home constructed in 2002, heated with propane.  With soaring propane costs, I need to do something whether it's a geothermal system, air source heat pump, hybrid or split system.  My wife and I are unsure what to think of the information presented to us by various contractors, each one toting their system as the best fit for us.   We are located in Michigan with cold winters and don't know which system would work most efficiently.  Any general advice or tips from similar experiences would be greatly appreciated.

Please don't do an Air Source heat pump in your cold area.

I'd say you have the situation that BEGS for geothermal. My suggestion is to contact Mike Dilling with Hoosier Energy Associates. He's the EarthLinked Sales Rep for your area, and could suggest a good contractor for your install. He's very knowledgeable about geothermal and air source systems.

His info:
Mike Dilling
Hoosier Energy Associates
79 W. 250 N.
Warsaw, Indiana 46580

574-269-2603 phone
574-269-4188 fax

I agree with Clark's recommendation to avoid an air source heat pump in Michigan. It just won't cut it in those winters. A hybrid system (some players in the HVAC industry are riding Toyota's coattails by milking the market appeal of "hybrid) might make sense if you have natural gas, but probably not with propane. A hybrid system burns gas during very cold weather but uses air source heat pump during milder weather.

Educate yourself on both DX and conventional geo. Bear in mind that installed cost will be much higher than air source or hybrid, but operating cost, if executed by a diligent, experienced installer, will be much less.

Thanks for the notes. We have one contractor telling us that an air source heat pump with electric strip resistance heating for temps below 34F will save us roughly 2/3 on costs, and that is based on 2.79/gallon for propane and our average usage of 2000 gallons per year. I just don't see how using electricity for 3 months is going save us that much, but maybe the reasoning is that the savings are in eliminating the massive amount of propane.

I have several follow up questions. Why is propane not a good idea with a hybrid system? Is this due to something mechanical in the system or personal experience? As for geothermal, we are awaiting estimates from a contractor for geothermal system consisting of a horizontal closed loop, 5 trenches at 100' long each. Is this more efficient than and open loop system using well water? I haven't found alot of information stating the disadvantages of this option, but have concerns as to whether this will affect the well supplying water to the house. Seems like a constant draw would lower the ground water even more. Our existing well is 160' deep, but the geothermal well acts like a point doesn't it, where the well wouldn't be as deep.

Thanks again. I will try to contact the gentleman you mentioned from Hoosier Energy Associates.

My only objection to propane is its expense. I'd be willing to bet that you won't be able to get it for $2.79 this winter. Comparing costs per Btu - A kwh of electricity has about 3400 Btu, and a gallon of propane about 92,000 Btu. The electricity used in strips is effectively 100% efficient (all the heat enters your ducts) whereas there is a flue loss for propane likely somewhere between 5-20% depending on furnace efficiency. You'll need to determine your cost per Kwh and whether you'd qualify for a lower rate often available for electric heat.

dkj1, put your numbers in this page and see how it works out.

calculator


Geothermal for me comes out at $5.86 per million BTU's with a COP of 3, which I am usually well above that.