all electric or propane back up?

Discussion in 'Geothermal Heat Pump Applications' started by HHarpel, Mar 29, 2013.

  1. HHarpel

    HHarpel New Member

    I have talked to a few geo installers and have gotten conflicting info. One tells me to do a geo heat pump with a propane back up furnace for when the geo cant keep up with the cold ohio winters, basically a split system. He told me when the system switched to the auxillary heat strips it drastically increases your electric bill and switching to propane is more economical. The other guy tells me to do all electric water furnace system or climatemaster and that only 10% of the strips should be on and using the propane shuts off the geo system so your losing the effectiveness of the geo and only using propnane, which is uneconomical. My husband and I are getting very frustrated with the conflicting info and he is getting leery of spending so much money for something that he is scared won't work. Any info would be appreciated.
  2. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Hi and welcome,

    Not to open up another rabbit hole for you.... but, I advocate the use of independant back-up/auxillary heat. Defined as a system that can provide you with heat if the electric is off, and provide supplemental heat to the portion of your geo that needs a little push on a few degree days a year. All electric would do it for me if I had a generator big enough to run the geo plus heat strips. Or a small generator big enough to run a big propane furnace in the event of power failure. Or a pellet stove with a 12 volt power inverter to run the thingy that spits the pellets in when it needs.
  3. ssmith

    ssmith Member

    Not an installer here, but I can give you an example from our 3 ton system. Running in 2nd stage, our system uses approx.1785 watts. Running in second stage with aux on (stage 3) the same system uses around 6060 watts. You can say that's a lot more energy, and it would run up the electric bill if aux ran all the time. In reality, it runs rarely. I've done some efficiency measurements, and our system runs close to 400% in stage 2 (cop=4). With aux running, the system is still around 187% efficient (cop=1.87). This is because when the aux strip is on, much of the heat is still coming from the geo system. Also, aux doesn't stay on. It cycles on and off as needed...maybe on only 15 min out of every couple of hours when it's really cold out. Since propane, oil, and electricity are close in price, I can't see propane or oil options as costing you less to run, especially when it's set up so the geo cuts off and the secondary sytem supplies all the heat when it's coldest. The bottom line, here, is to find a good installer who will design and install a system that works like it's supposed to. Geo done right is the cheapest and most comfortable way you'll ever find to heat your home, imo. FWIW, the cold NY winters where I live are as cold or colder than what you get in Ohio.

    As far as backups go, where I live, our electric grid has been much improved over the last 20 years and we rarely lose power. I do still have a wood stove that I can heat the house with. I haven't burned it in the last 2 years since we got the geo system though. I couldn't buy wood for what the geo costs us to run.
    Last edited: Mar 29, 2013
  4. HHarpel

    HHarpel New Member

    what brand system did you install? And how many feet of loop do you have installed?
  5. ssmith

    ssmith Member

    Ours is a climatemaster tranquility 3 ton system. The loop is a racetrack type installation with 3 x 200' trenches with 600' of loop in each trench. There is also a 100' run out and back to the loop field with the supply and return lines from the house. The loop is buried about 7' deep in a pretty wet soil with a lot of clay content. Works great where I live, but your area might be different. I wouldn't get hung up on brand or even installation. You just need to find an installer you can trust and go along with his plan.
  6. johnny1720

    johnny1720 Member

    I had an electric resistance backup installed with the ClimateMaster Heat Pump. I dont use the electric resistance very often at all. I also have a pellet stove insert that will heat my house pretty well it cAn be ran off a generator. The electric resistance setup costs about 200 and it is fully integrated into the heat pump. The propane is either already existing and dirty or will need to be purchased And installed.
  7. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader


    You have mail.

    I tend to use the cheapest fuel available after the Geo system.

    Assure your husband that a properly designed system will work.

  8. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Yes with geo you wil spend a lot more on electricity than you are used to. You will however spend far less on additional electricity than you will on propane or fuel oil.
  9. GoHuskers

    GoHuskers New Member

    I live on an acreage so NO natural gas, propane is as expensive as electric ($.008/kw) so my is all electric.
  10. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Attached is an article we wrote to illustrate that even with more electric supplement heat you can save overall operational costs.
    $100 in electric supplement heat is nothing, usually you cannot even get your additional propane heater serviced for that amount. Plus you save due to lesser upfront, lesser pumping and higher COP of the smaller unit.

    Attached Files:

    Tamar likes this.
  11. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Thanks Doc. The linkedin geoexchange group has a spirited discussion about sizing going on as I type this. You won't be suprised to learn I am standing alone in the 3 ton camp for a 50MBH load.
    One of the respondents asked for model predictions with higher electric rates and in the Lansing MI area they favor the 3 ton more as they climb.
    Not always true of course.

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