1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
    Caluwe - Passion for Fire and Water ( Pellet and Wood Hydronic and Space Heating)

Anyone have a geothermal heat pump system?

Post in 'The Green Room' started by BIGDADDY, Oct 6, 2012.

  1. BIGDADDY

    BIGDADDY Feeling the Heat

    Joined:
    May 17, 2012
    Messages:
    356
    What are the positives and negatives? Is it worth the cost and are there any government assistance ?

    Thanks

    Helpful Sponsor Ads!





  2. johnny1720

    johnny1720 Member

    Joined:
    Mar 6, 2007
    Messages:
    196
    Loc:
    The Great North East
    I have a 4 ton Climatemaster unit that is water to air. I have had it for like 9 months and I love it.

    -Positives, really cheap to heat each month and it does not matter what the outdoor temperature does as long as it was installed and designed correctly.
    -Negatives, expensive to install and my lawn just started to look normal about 2 months ago.
  3. BIGDADDY

    BIGDADDY Feeling the Heat

    Joined:
    May 17, 2012
    Messages:
    356
    Do you think $18,000 for a 5 ton climate master the tranquility is a good price with 1200 feet of horizontal pipe in my yard?
  4. schlot

    schlot Minister of Fire

    Joined:
    Nov 21, 2011
    Messages:
    771
    Loc:
    Iowa
    5 ton is a big unit, how many sf are you heating? What kind of soils do you have?
  5. sloeffle

    sloeffle Member

    Joined:
    Mar 1, 2012
    Messages:
    117
    Loc:
    Morrow County, Ohio
    I have a 4 ton three stage ( two stages of geo and heat strips ) Waterfurnace that was installed about a year ago. The AC and free hot water heating is great, especially this summer. The heat is nice but it is not hot heat, it is warm heat. It takes awhile to get use to if you have been heating with gas or propane. I have 2400 feet of pipe in the ground connected to a 4 pipe horizontal loop system. I am in central Ohio.

    The trenches in the attached pics are approximately 6 - 7 feet deep. The pipe at the "bottom" of the trench on the right comes back on the "top" on the left side of the trench. The "top" of the trench is approximately two feet ( 4 - 5 feet deep ) feet from the bottom of the trench. The geo lines pull or push heat from a approximate 1 foot diameter area.

    pic1.JPG


    pic2.jpg


    Scott
  6. BIGDADDY

    BIGDADDY Feeling the Heat

    Joined:
    May 17, 2012
    Messages:
    356
  7. schlot

    schlot Minister of Fire

    Joined:
    Nov 21, 2011
    Messages:
    771
    Loc:
    Iowa

    Just to be clear, when you say 2400 feet of pipe you mean in 1200 feet of trench correct? 2400 feet includes both supply and return lines correct?

    A typical (there really is no typical by the way) length of trench is 200 to 300 feet per ton. This is for excavated installations. Horizontally directional bored lines and vertical installation are more efficient and therefore less trench length is needed per ton.

    Horizontally bored systems are very popular, especially with small sites.
  8. schlot

    schlot Minister of Fire

    Joined:
    Nov 21, 2011
    Messages:
    771
    Loc:
    Iowa

    Bigdady, where are you located? Typically the top pipe is installed around the frost depth, with other pipes below that. Generally native soils are used for backfilling. The pipe used is pretty tough, so unless there are problems with a lot of rock it should be ok to use the clay.

    You may want to ask if the contractor used software to calculate the size of the system. It's very common for contractors to size a system to large. This actually creates more problems than an undersized system.
  9. schlot

    schlot Minister of Fire

    Joined:
    Nov 21, 2011
    Messages:
    771
    Loc:
    Iowa
    The second point is another reason directionally bored systems are gaining favor. The only disturbance to the yard is for the pits needed for the headers are each end of the lines.

    The last project we were involved with, the loops were actually bored below the new building being built.
  10. sloeffle

    sloeffle Member

    Joined:
    Mar 1, 2012
    Messages:
    117
    Loc:
    Morrow County, Ohio
    I could not agree with you more about peoples opinion on how much pipe you need per ton. I talked to three different installers in my area. All three of them said they would do no less than 600 feet of pipe per ton. All three said that pipe and excavation ( for my situation ) is relatively cheap so their is no use to skimp on the amount that you put in the ground. We have very heavy clay soil so that might have something to do with it. One guy quoted my 24k for a 3 ton system but did not say how much pipe he would put in the ground. I ran away from that guy as fast as I could. I drive by his house every once and awhile. He has some nice toys sitting in his drive.

    I have two 300 foot long trenches approximately 5 feet apart. Their are two pipes per trench. So yes, their is 1200' of pipe per trench. By the end of last winter, which was very mild BTW. I would say my loop temperatures were in the 40's as guess. With less pipe in the ground I would say it would of been even less.

    I did alot of reading on http://www.geoexchange.org/forum/ before I pulled the trigger on the system and pipe configuration.

    Scott
  11. sloeffle

    sloeffle Member

    Joined:
    Mar 1, 2012
    Messages:
    117
    Loc:
    Morrow County, Ohio
    Could not agree with you more. Please see attached picture for the "carnage" done to my hay field. And that was only after one trench. :confused: The grass still has not grown back due to this years drought and trying to get it planted in the spring.

    carnage.JPG


    Scott
  12. schlot

    schlot Minister of Fire

    Joined:
    Nov 21, 2011
    Messages:
    771
    Loc:
    Iowa
    Wow, that looks like some trenches from WW1! LOL.
  13. schlot

    schlot Minister of Fire

    Joined:
    Nov 21, 2011
    Messages:
    771
    Loc:
    Iowa
    Local soil conditions are highly variable, so your soils may call out for extra length per ton. Soil tests can be run for measuring geothermal conductivity. This information can be used in designing the field lengths needed. Of course some contractors don't like this information as it potentially reduces profit for them.
  14. BIGDADDY

    BIGDADDY Feeling the Heat

    Joined:
    May 17, 2012
    Messages:
    356




    I am in central Pa. What is the "top pipe"? I think the frost line here is 3 feet but not absolutely sure.
  15. schlot

    schlot Minister of Fire

    Joined:
    Nov 21, 2011
    Messages:
    771
    Loc:
    Iowa
    An excavated trench typically will have several "pairs" (supply and return) pipes installed above each other. The top most pipes will be installed just below the frost line, with additional pipes installed at 12" to 18" increments below them. The upper most should be below frost line. 36" sounds about right for PA.


    I hope I'm not confusing things, but I've seen too many HVAC systems installed incorrectly and hope to help you ask the right questions of your contractor.
  16. peakbagger

    peakbagger Minister of Fire

    Joined:
    Jul 11, 2008
    Messages:
    1,634
    Loc:
    Northern NH
    In rocky northern NH most of the installs are in deep boreholes, they recomend a depth of 300 feet per ton. Once they drop the loop in the ground, the grout the pipe in with a conductive grout. It doesnt trash the property as badly but drilling hole thru granite isnt cheap. At least the government is paying for 30%.
  17. jdp1152

    jdp1152 Minister of Fire

    Joined:
    Oct 4, 2012
    Messages:
    759
    Loc:
    Massachusetts
    I'm in the final process of deciding between three bids for geo install in MA. A bit of a process for a retro fit and by no means cheap, but I have an aging oil/baseboard set up and and two dead AC units so replacing with geo using Mass Save 25k 7yr interest free loan and the 30% tax credit make the ROI pretty quick when factoring in new ACs, Oil Tank, and burner + labor.

    300ft per ton sounds incredibly high. I've read 140-150 and at most 170. The bid I'm leaning toward is 170ft/ton over two wells.

    EDIT: Also to add, I only plan on supplying heat to the cooling load and supplementing with electric and wood heat.
  18. sloeffle

    sloeffle Member

    Joined:
    Mar 1, 2012
    Messages:
    117
    Loc:
    Morrow County, Ohio
    Bigdaddy,

    I am not meaning to try to confuse you more with my setup and the pics. I also wanted to show you that having your trenches dug leaves alot of mess. You will find their are at least 500 ;) different ways to setup a loop field for geothermal.

    I just wanted to show you mine because I know it works. We are cool in the summer and warm in the winter. Our electric bills with the geo are cheaper with an additional 700sq ft than they were with just with a propane furnace and a normal AC unit.

    IMHO I would talk to at least three different installers and get their opinions. I have a Waterfurnace because most of the dealers in my area install and service them. Their are four geo furnaces that you can get most people to agree on that are good. They are Florida Heat Pump, Waterfurnace, Climatemaster and Bard. The geo units that Trane, Carrier etc make are just knock offs of the aforementioned units from what I have been told. I am however not sure if Baird is available outside of OH. I think if you choose a reputable dealer of one of these you should be okay.

    As schlot eluded to, do NOT let them skimp on the amount of pipe per ton they put in the ground. If you get all types of different opinions then tell them you want a test done on your soil. Their are plenty of stories over at geoexchange were folks have not had enough pipe put in and they constantly running their heat strips. My excavator put a unit in himself. He has half the pipe in the ground that I have for the same unit and has complained to me about how high his electric bill is in the winter due to the heat strips running. If you were in my area I would tell you no less than 3k feet of pipe in the ground for a 5 ton unit.

    Scott
  19. schlot

    schlot Minister of Fire

    Joined:
    Nov 21, 2011
    Messages:
    771
    Loc:
    Iowa

    It's all about the soil types. It's high compared to the soils we commonly see here, but could very well be whats needed for the soils peakbagger encountered.


    Again, there is no "typical", more likely an average value people will use. If you are either side of the average length per ton, you could be paying too much, or not getting enough length for your application.
  20. woodgeek

    woodgeek Minister of Fire

    Joined:
    Jan 27, 2008
    Messages:
    2,727
    Loc:
    SE PA
    Why this sizing decision...are you going to do economics on a bigger system (e.g. for January mean temps). And if you only want such a small load, why not just go with a minisplit??
  21. BIGDADDY

    BIGDADDY Feeling the Heat

    Joined:
    May 17, 2012
    Messages:
    356
    Thanks everyone for your advice. Lots of good information to maul over.
  22. johnny1720

    johnny1720 Member

    Joined:
    Mar 6, 2007
    Messages:
    196
    Loc:
    The Great North East
    I have also heard some bad press about people installing geothermal that are not accredited. If they are accredited they can give the 30% Federal Tax rebate paperwork to you for tax time. I have 2250 feet of pipe installed at an average depth of 6 feet, one of the run is doubled up so the bottom is 15 feet deep and the top one is about 6 feet. I think the geothermal was the best investment I have ever made in my home. Where exactly are you located? The guy that did my install was from Salamanca, NY and he travels all over doing these for people. I know he has done a dozen or so down in PA and probably 40 or so in Western NY. I installed mine in Feb. and we finally got on the lawn with the dozer about June. The drought did not help the grass grow but the lawn looks better now than before the install.
  23. johnny1720

    johnny1720 Member

    Joined:
    Mar 6, 2007
    Messages:
    196
    Loc:
    The Great North East
  24. begreen

    begreen Mooderator Staff Member

    Joined:
    Nov 18, 2005
    Messages:
    48,325
    Loc:
    South Puget Sound, WA
    We were quoted $23K for a complete geothermal system including excavation costs and $8.5K for an air heat pump system. Cost, long term reliability, and few vendor options were the cons we weighed against putting in geothermal. For less than half the cost of the geothermal system we put in a very good 2 stage air heat pump. Our peak house electric bill with this system is under $125 during the shoulder season or less than $2/day for the heating costs. A geothermal would save us maybe another 20% during our shoulder seasons. We heat mostly by wood once it gets below 40F. By the numbers the ROI would be so long term that it exceeded the life of the heat pump. With $13.5K saved we applied it toward solar panels instead.
  25. Seasoned Oak

    Seasoned Oak Minister of Fire

    Joined:
    Oct 17, 2008
    Messages:
    3,672
    Loc:
    Eastern Central PA
    Very good insulation and a good heat pump may well be more cost effective than a GEO system.

Share This Page