Shopper with Lots of Questions about Geothermal Heat Pumps

Discussion in 'Quotes and Proposals' started by amailmanyouknow, Aug 13, 2010.

  1. geome

    geome Member Forum Leader

    I'm a homeowner. Like you, I didn't know much about this stuff until our system was installed last year. Keep asking questions. :)

    Heat strips are basically electric heating elements or coils (like in a portable electric heater or a toaster). Ours came in increments of 5kW. We have a total of 15kW of heat strips for our first floor and come on in 5kW stages (every 5 minutes or so) until the thermostat is satisfied (if our geothermal system cannot otherwise satisfy the thermostat.)

    They can be sized to meet just the supplemental heat demand (see below) or the heating requirements of the entire house should the geothermal system lock out (or somewhere in between.) I think sizing for the house is better if you are in a climate that could freeze your pipes should the system lockout. Or, your goal could be to just keep the pipes from freezing and not to keep the house comfortable.

    Heat strips, heat packs, etc., can be both:

    1) a supplemental (a.k.a. auxiliary, or aux) heat source designed to be used at the same time the geothermal unit is running when the outdoor temperature is below the geothermal design temperature (since geothermal units are not typically sized to meet 100% of the heating load in heat dominated climates due to higher installation costs.) Thermostat setting changes of more than a few degrees can also bring on auxiliary heat depending on the thermostat and settings used.

    2) a backup (a.k.a. emergency) heat unit to be used in the event of a system lockout (failure.)
    Last edited: Aug 16, 2010
  2. Looby

    Looby Member Forum Leader

    The residential heating rate is only available if you're heating with electricity.
    After installing a geo heat pump, you have to call PECO to request it. They
    may want to send someone out to verify that your heating is "all electric" --
    I don't know whether they'd blacklist you for owning a propane fireplace.

    I'm in central Chester County. I'd be happy to show you our geo system;
    see a DSH and 'heat strips' first hand. Send me a PM if/when interested.

    BTW, ignore the "Industry Professional" tag in my profile -- I'm just a
    techno-geek homeowner. ...Not gonna try to sell you anything.

    Last edited: Aug 16, 2010
  3. amailmanyouknow

    amailmanyouknow New Member


    When I tell you about everyone giving me a different opinion, I mean REALLY different...Here's something I got in the email today...

    It's very frustrating. I have a quote for $15K for a 2-ton system, $21 for a 3-ton (@same price from a few different contractors). None of *them* said I needed to keep my oil burner. I am really glad I found this forum.

    Right now, our central A/C has the fan outside, and the rest of the system is in the attic. We only have *1500* sf in this house.

    I wish there was a smiley for pulling out my hair.
  4. amailmanyouknow

    amailmanyouknow New Member

    Blacklist, ha! PECO would do it, too....or they would try. But for the amount of propane we use I would say that they would be hard pressed to prove we "heat" the house with it!

    I will definitely do that. Thanks!
  5. amailmanyouknow

    amailmanyouknow New Member

    Thanks for all the explanations. I really appreciate the help!
  6. sunnyflies

    sunnyflies Member Forum Leader

    I have an old house too, though not quite as old as your's. Mine's only 170 years and it's made of wood, but my story is similar.

    When I started looking into geothermal I knew very little. I was getting widely different stories from each company I spoke with and subsequently didn't know who to trust. More than a few told me I could not use geothermal in my leaky old house. How wrong they were.

    Fortunately someone who had a geothermal system sent me to this forum. I didn't understand most of what was being said so I started taking notes and searching threads here for answers as well as googling some terms. Eventually I figured out enough to know that my hunches about the installers I had met up until that point were pretty good, they knew a bit less than I did about geothermal. I ended up looking farther afield and also getting names from manufacturers' websites.

    I went with Waterfurnace and one of its master dealers who had a list many pages long of references for me to call - and I called plenty. He turned out to be excellent and so has the system he put in. My house was so cosy last winter, something it had never been before, plus we saved about $4000 in winter heating costs over the year before. And, it has been deliciously cool all summer.

    Better yet, we just put in solar panels and our bill for cooling the house came to 19¢ for all of July which was a scorcher.

    Keep looking into geothermal, it will be worth all the effort you put in. You will have to put in ducts plus returns, but it's not that hard to do if you can run a heat duct and a return up through a closet to the attic for the second floor. Yes, I know old houses don't have closets, but we used a small space next to the chimney which had been used as a closet. Good luck.
    Last edited: Aug 19, 2010
  7. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    A project we are starting next week had wildly disparite loads and caused homeowner similar concerns.
    House is 3 stories above daylight basement on a relatively compact floor plan (~1,200ish/floor).
    Two systems will be employed to avoid duct soffits on ground floor (1 up, 1 down).
    Homeowner has had a difficult time trusting design with so many different recommendations.
    We finally used a reverse approach against the other front running bidder.
    To paraphrase: the final area of concern was basement and ground floor. My heat loss calc 37MBH, other guy 55MBH. 3 ton for me (driven as much by cooling load as historic windows aren't low E) 4 ton they.
    Our approach was to apply my 3 ton unit against his loss calc. Finding was $44 more/yr to operate due to auxiliary heat. Additional vertical loop and larger unit about $3,500 more. With $44/yr savings the after tax credit ROI on the extra ton was about 55 years.
    If we used his 4 ton to satisfy my load it cost more to install and $3/yr extra to operate.
    My system- win/win.
    Unfortunately other guys loss calc totals were available but not data that was employed to calculate it, so that comparison was out.

    Point is I can't criticize the other companys' design philosopy, but I would have liked to see where we are so different in loads. At the end of the day I still feel 3 ton made more sense regardless.
    Folks will give you different design ideas, you might ask them to plug other equipment into their load calcs and see if other choices make equal or more sense.
    Good Luck,

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