I’m considering a geo-thermal heat pump for a new home near Chicago (the alternative would be natural gas 90% furnace and 14 SEER 2-speed A/C). The contractor I’m bidding uses WaterFurnace, and I’d be using forced air delivery (due to the high cost of radiant). I’m interested to hear the experiences of others who have this in their homes.
- Does it provide adequate heating/cooling?
- Do you have auxillary heat; if so, do you know how often it runs?
- Reliability of the heat pump?
- Maintenance frequency and cost?
- Anything else you think might be useful.
The house will be tight and well insulated. I’m planning to install an energy recovery ventilator, air cleaner, and humidifier.
The cost is significantly higher (~$15K) than a high-end conventional system. I expect a moderate decrease in monthy utility costs with geo-thermal, but that’s not the primary reason I’m considering it. I’m trying to be environmentally conscious and less dependent on natural gas supplies.
Thanks!
Replies
S Erik,
I built a 2800 sq ft. ranch with most of the center vaulted (center of ceiling 15 ft above the floor) nine foot ceilings 2x4 walls with spray cellulose insullation in the walls, full basement, and built in a very windy area. The owners tell me that their bills run anywhere from 120 to 220 bucks a month with 175 being the average. They are using electric for everything. House is geothermal with 6 wells 150 foot deep as my heating guy is not a believer in the trench and pipe method. The system does a great job and the house is very comfortable. They do not run the air cond. a whole lot as the wind is always blowing and opening some windows front and back takes care of it except in really hot weather. House is in N.E. Oh so we do get cold weather. They are very pleased with it.
Mark
Mark,
Scott
S Erik,
It might be that we have higher electric rates in my area than you are used to. For example my house is 2000 sq.ft. 3 bedroom heated with gas/gas water heater/range and my electric bills run between 80 and 120 bucks a month(and we don't leave lights on all over the place and I rent my shop so the electric for that is not reflected in my bill.) My customers have an almost 50 percent bigger house (MOre if you count their basement )and higher ceilings, and live in a windy area, yet they are heating water/the house/ cooking plus all the other things in a conventional system, and they are only paying what I told you in my previous post. I think they are doing great, not to mention when they do run their air it costs hardly anything. How much energy does it take to pull cool air off of 52 degree water? not much. They are certainly very pleased with it, I don't think you could talk them into any other system if they had it to do over.
Mark
Maybe I am misunderstanding you. Geothemal use the ground source water loop on the condenser side of the unit. The 52 degee water is used as a heat source durring the heating season and a heat sink dirring the cooling season. With the actual earth being the source or the sink for the latent heat. The actual heat transfer within the house is done bt the freon in the evaporator side of the system. The efficiency of a geothermal unit comes from the constant earth temperature vs. an air to air heat exchange for normal air conditioners or heat pumps.
Dave
To add more numbers for comparison, 6000+ sf, one 800' well, all-electric, similar utility bills to what you stated. 4 ton ground source heat pump. Little milder climate in mountains of NC, but still a 14 degree design temp. Design temps range from 3-12 in OH according to the program I use. The geothermal has been operating as advertised (actually tests closer to 5 ton performance) without a hitch for 2.5 years now, fwiw.
Built my inlaws house in 91 and 92 with a 5 ton Waterfurnace geothermal unit. All electric home. Average monthly utility cost of around $100.00. design temp for area is 10 degrees. House is a total of 5200 square feet of conditioned space. Highest bill this winter has been $164.00. That is heating cost and the rest of an all electric home operation.
Take your plan to your local utility company and see if they offer a load estimate and cost of operation service. The rural electric company where my inlaws live gave me a breakdown for regular air to air heat pump, geothermal, and LP gas. NG was/is not available there.
System maintenance cost have been about $150.00/ yr. Had to replace the compressor 3 years ago, but think now that it was because of a low voltage problem with the electric service, The electric company and I are still trying to solve that problem.
My experience with air to air heat pumps has been about a ten year life span on the compressors. The two other geothermal homes located near my inlaws home have gone over 12 years now without compressor problems. Both of them have horizontal loops and on occassions have had the auxilary heat operate to keep up durring extended cold winters, but not enough for them to be negative about the systems. FIL auxillary heat has nver been called on in 11 years. Five 165' deep loop holes and tighter construction than the are two home are the reason for that.
Dave