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  1. #1
    Join Date
    Jan 2010
    Posts
    10

    Questions about Geothermal

    We have a 20 year old, 2-story, 2000 square foot (finished) house with a ~1000 square foot currently unfinished basement. Right now I have an electric heatpump that is old, grossly under-sized, and produces HUGE electric bills. We are getting ready to pull the trigger on a WaterFurnace Envision Dual Compressor unit to replace the existing equipment. We will also be getting a complete duct overall since the current stuff is really screwed up. I have a couple questions that I am looking for suggestions/comments/advice:

    1. One contractor is recommending a 3-ton Dual Compressor unit with a 4 ton loop (vertical closed). Another is recommending a 4-ton Dual Compressorunit with a 4 ton loop (vertical closed). Seems like a big difference in equipment and was wondering if the extra cost to operate a 4 ton unit is worth it. What is a good loop operating temperature?

    2. Bypass humidifer (AprilAire 600), steam humidifier, or other? I would like appropriate comfort to reduce dry skin, etc. but don't want a huge extra monthly electric cost. Also, depending on the type, what is the best placement for it (supply vs. return).

    3. Get the standard 2" MERV-11 disposable filters that come with the WaterFurnace or upgrade to a HEPA-like filter for better filteration, but a higher cost?

    4. We currently have a new 80-gallon electric water heater, is another tank or anything necessary to ensure enough hot water.

    5. Two zones are currently proposed: 1 for the 2nd floor and 1 for the 1st floor and basement (to be finished). Is this okay or should the basement be on a separate zone? Is it worth the extra thermostat and ducting cost if dampers can be used?

    6. 4 vertical wells are currently proposed in a box layout, 10-12 feet from garage and 10-12 feet between holes in order to avoid surrounding trees. I believe that the depth of the holes are to be 150' each. Is there enough distance between the holes?

    I think that's it for now. I'll update or reply with any additional questions.

    Thanks for the help!

  2. #2
    Join Date
    Apr 2008
    Location
    Northwest Arkansas via Chicago Area via Straight Up from There on Lake Superior
    Posts
    1,411
    What are HUGE bills and where are you? Have you addressed any house issues first? Would be unpleasant to put in an expensive geo or any other unit to find that it didn't solve your problems.

    I will give my observations as a HO that was hot to put in geo with hot water recovery. Make sure you understand it. It's more complicated with wells than any other system I looked at. Determine how long you will live there. Find very experienced contractors. Compare your actual geo proposal costs after all credits and rebates against high end HP (or DFHP) actual costs after all credits and rebates. After all of the trying to force fit geo to my situation, I finally ran the numbers and given our energy lifestyle I could not justify it and probably wouldn't recover the extra cost in our lifetime. You may be able to but prove it!

  3. #3
    Join Date
    Oct 2008
    Location
    OFFICES IN : ARIZONA - NEVADA - TEXAS
    Posts
    258
    jerryd 2008 is right don't spend it until your ready.. The 20 year old home was built less eff. than the ones today and you already have questions with regards to the contractors choice.. By all means you need a detailed Manual J heat gain - heat loss calculation to be done the contractor should offer you this... have your electrical service evaluated for any oxidation , the newer equipment will probably require a smaller breaker.. After this then make your evaluation..
    "Rock-n-Roll " Ain't noise pollution..

  4. #4
    Join Date
    Jan 2010
    Posts
    10
    Average electric cost for the past 3 years has been $3600/year.

    No NG available at the road; would have to get propane tank for dual fuel.

    Completely new circuits will be run for the new system and 1 will actually be larger than existing.

    I have a detailed GEOLINK report for the 3 ton, dual compessor, 4 ton loop proposal.

    Cost for unit and all ductwork, zoning, etc. after all rebates and tax credits is twice as much as a replacement electric heat pump without any ductwork changes quoted 2 hears ago.

  5. #5
    Join Date
    Jan 2010
    Posts
    10
    Also, our location is Southwest Ohio.

    Please elaborate on possible house issues...

  6. #6
    Join Date
    Oct 2008
    Location
    OFFICES IN : ARIZONA - NEVADA - TEXAS
    Posts
    258
    A Heat-Loss / Heat-gain calculation would be worth it and a plus if your going for a rebate or tax credit . & you could save the headache of firing gas if you considered a water source or geo Heat-pump
    "Rock-n-Roll " Ain't noise pollution..

  7. #7
    Join Date
    Apr 2008
    Location
    Northwest Arkansas via Chicago Area via Straight Up from There on Lake Superior
    Posts
    1,411
    Quote Originally Posted by shigadeyo View Post
    Average electric cost for the past 3 years has been $3600/year.

    ...
    WOW, $300/month! What kind of cooling and heating temps do you use? Any big non-HVAC costs in there? Have you compared your costs to neighbors with similar size and style?

    May be an apple to oranges compare but our 3500+ sqft 2-story house built in 1994 in NW Arkansas with very large under the house garage (almost like a good sized basement) has consistently run $1500-1600/year total NG and electric. But we do set cooling at 78-79 and heating to 69-70. Summers can get hot but winter is only 2 months with a few below 10 F days. Don't have new costs for the new DFHP we installed last July.

    Quote Originally Posted by shigadeyo View Post
    Also, our location is Southwest Ohio.

    Please elaborate on possible house issues...
    At those costs, I would definitely look at blower door test along with infrared scanning for problem areas to address. What's the attic insulation like? It's amazing what an additional 6" of cellulose over the top of any fiberglass along with a dozen tubes of caulk and cans of foam and some new door gaskets can do and at a reasonable cost.

  8. #8
    Join Date
    Jan 2010
    Posts
    10
    Oh, I completely forgot to say the temps that the thermostat is set on...

    63 degrees in the Winter!
    76 degrees in the Summer!

  9. #9
    Join Date
    Apr 2008
    Location
    Northwest Arkansas via Chicago Area via Straight Up from There on Lake Superior
    Posts
    1,411
    Quote Originally Posted by shigadeyo View Post
    Oh, I completely forgot to say the temps that the thermostat is set on...

    63 degrees in the Winter!
    76 degrees in the Summer!
    Those seem pretty reasonable to me. Doesn't appear that you have unreasonable expectations, but I'm just a HO. Can't you just open the door in the winter and maintain 63?

    What about the other questions?

  10. #10
    Join Date
    Jan 2010
    Posts
    10
    Are house is all electric, so the other big draws - when in use - include the water heater, range, dryer, and a second refrigerator.

    It talking to friends and family about totatly energy costs, they are spending a significant amount less on larger and sometimes older homes. Our Jan, Feb, Mar bills make up nearly half of the yearly cost. I would really like it to be 70 in the house in the Winter as it says 63, but feels more like 50. This could be because heat from an electric heat pump is cool to begin with (95). I am constantly chilled through and it is like a suana in the Summer.

    It probably would be better just to open the door. However, it has been extrememly cold and windy here (single digits and teens). Interestingly enough, when it goes from really cold to warm outside (40-50), it will take the house several days to warm up meaning that it is actually more comfortable OUTSIDE than in!

    Another big issue is that the master bedroom is above the garage. So really, all sides but one are more or less exposed, so the temperature in that room is easiy 10 degrees colder or warmer than the rest of the house. Right now with the system running nearly constantly trying to GET to 63, that room is 55!

    I used about a dozen tubes of caulk making sure everything is sealed well from the outside. More attic insulation is also on my list and I will most like be doing it soon when I am up there to fish a wire for the second zone.

  11. #11
    Join Date
    Apr 2008
    Location
    Northwest Arkansas via Chicago Area via Straight Up from There on Lake Superior
    Posts
    1,411
    Quote Originally Posted by shigadeyo View Post
    Are house is all electric, so the other big draws - when in use - include the water heater, range, dryer, and a second refrigerator.

    It talking to friends and family about totatly energy costs, they are spending a significant amount less on larger and sometimes older homes. Our Jan, Feb, Mar bills make up nearly half of the yearly cost. I would really like it to be 70 in the house in the Winter as it says 63, but feels more like 50. This could be because heat from an electric heat pump is cool to begin with (95). I am constantly chilled through and it is like a suana in the Summer.

    It probably would be better just to open the door. However, it has been extrememly cold and windy here (single digits and teens). Interestingly enough, when it goes from really cold to warm outside (40-50), it will take the house several days to warm up meaning that it is actually more comfortable OUTSIDE than in!

    Another big issue is that the master bedroom is above the garage. So really, all sides but one are more or less exposed, so the temperature in that room is easiy 10 degrees colder or warmer than the rest of the house. Right now with the system running nearly constantly trying to GET to 63, that room is 55!

    I used about a dozen tubes of caulk making sure everything is sealed well from the outside. More attic insulation is also on my list and I will most like be doing it soon when I am up there to fish a wire for the second zone.
    To me it's a tip off when others are doing much better than me in larger or older houses that I need some serious house envelope improvement. Can't give me at least 70 in the winter and is a sauna in the summer would add further resolve to my quest to improve the envelope.

    Is there insulation in the bedroom floor above the garage? Can you add it? Maybe foam. Got drapes on the windows that you close at night? We have the exact same situation of MBR and bath over garage, but the garage ceiling is finished. Otherwise I would seriously look at adding more insulation there since the bath floors a re a bit cooler than we would like.

    Again, I'm no pro but I have owned a number of old to new houses from Lake Superior to Chicago to Arkansas, and I think that your description necessitates a serious review of the house. Just caulking here and there may help some but IMO an infrared scan can point out exactly where the problems are. I used my digital camera and followed the scanner around taking pictures of every spot he found and notes on his ideas for solutions.

    We are not allowed to discuss costs on this forum, but one thing to consider is that saving just 1 ton of geo capacity is probably going to save you multiples of the cost of the analysis and solutions (I'm not talking replacing the windows though). Even if you decide that geo isn't cost effective, you probably will save on a new HP and your comfort will go through the roof. Heck, you may be able to get 70 in the winter and 76 in the summer with little humidity.

  12. #12
    Join Date
    Jan 2010
    Posts
    10
    Based on your recommendations, I have contracted with an independent local organization (http://www.homeenergycheckup.com) to come in and to a full energy audit complete with blower door test, thermal imaging, etc. to figure out my current state and what is recommended for improvements before I pull the trigger on a complete geothermal overhaul. I'll let you know how it turns out! Thanks again for the help.

  13. #13
    Join Date
    Aug 2009
    Location
    Dell Rapids, SD
    Posts
    44
    Don't forget about this...
    http://www.waterfurnace.com/event/

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