Posted By jared on 12/19/2008 11:10 PM
Hi I was just trying to get some input on a water to air Geothermal Heat pump. Last year it cost me about $4500 for propane. I have a 3800 sq ft house on 10 acres, an a neighbor with a backhoe & bulldozer.
Here are some of my stats.
Detroit area
20 year old 2 story 3800 sq ft with 4ft crawl space and pool
existing furnace 80% efficient 110,000 or 120,000 btu no a/c, down draft 1st floor
30,000 btu blue flame space heater in Great Room 1,000 sq ft with 4 heat registers to furnace
Old 90,000 btu furnace was better and didn't blow the drapes around when it came on
High water table mostly sand, sallow well around 10ft for water. Dig 4ft an you hit water.
Propane $2.70 November
electric .08 cent kWh
I am not loaded the only reason I have such a big house is because I spent my childhood building it with my father instead of going to Disneyland.
Some of the question I have are.
1) Is it even possible to heat my home with just a Geothermal heat pump or should I consider a split system with a propane furnace?
In the Great room I have 2 section that could be used for radiant floor heating, the weight room and entry way. Both are on a slab an about the same size 12ft x 12ft x 2= 288 sq ft, there is 4 heat registers in the room.
2) Is 288 sq ft of radiant floor heating enough to replace my 30,000 btu space heater?
3) Will my existing duct work?
4) I would like to use a variable speed blower is that possible? Noise is an issue.
5) Could I use my pool in a hybrid loop system for cooling the house in the summer?
6) What loop system is best for heating in my situation? I am considering a closed loop at 10 to 12 ft deep, length is not an issue plenty of room here.
7) Could I use my existing furnace and just add a air handler?
8) How much would it cost to install?
Thanks for your input.
I have numbered your questions so that I can respond.
1) yes most geosytems are designed to be the only heat source with a small back up electric heat strip for the really cold temps.
2) can't answer this one. It depends on how close together the pipes are in the floor and what kind of heat loss the rooms have
3) maybe on site inspection would be needed
4)variable speed blowers are available on heat pumps
5)possibly. There is a poster on these boards who uses his pool. The size of the pool and the cooling load of the house will determine if it will work.
6) if you have water table at 5', a closed horizontal loop would be the way to go. If you can get 10 ' deep with out caving in you would have a great system. 5' deep would work satisfactorily.
7) yes, this is what is called a split system. It would be an option for you. Again an onsite inspection would be needed.
8) If you were to hire a contractor, your install cost would probably be between $25,00 to $50,000. There are too many unkowns variables for me to narrow the range. An onsite visit by a installer could give you a better idea,
Hope this helps