Electric Usage

Discussion in 'General Discussions' started by dpwct, Mar 6, 2009.

  1. dpwct

    dpwct New Member

    I am considering a waterfurnace system for a new house in Connecticut. 4 ton with vertical closed loop NSH048, 2 wells total 540 feet. 3 zone system with HRV. The hose is new and insulated with icynene.

    I have been proposed a 15kw backup electric heat and 60 gallon electric water heater.

    I am being told that I may need 400 amp electrical service instead of 200 amp. Wondering if anyone has experience with this - seems like 200 amp should be more than enough, electrician says we are on the edge - looking for real world experience with Geo.

    No other strange loads - 2,600 SF house, hot tub, electric dryer, water well pump.

    Any other recommendations regarding system, options, questions to ask etc would be appreciated.

  2. Rgausman

    Rgausman Member

    Welcome to GeoExchange,


    With a tight 2600 sf home, would you be OK with a 10KW? This would put out about 36,000 BTU's vs 51,000 BTU's for 15KW. Will you have any other heat source such as a pellet or wood stove?

    Will you have two hot water heater tanks for the desuperheater?

    WF HP --> unpowered large preheat tank --> electric powered hot water tank.

    Also, I did notice that "2 wells total 540 feet" is equal to 135' per ton. Is this using 1.25" HDPE pipe for the loop? I know of one person up in Connecticut who is having problems with a 4-ton system with two 225' bores (112' per ton).

    Bob G.
  3. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    It all depends on your load calc

    If you want the electric strips to just serve as a backup / supplemental, then 10Kw might suffice.

    Just understand that 10kw electric alone probably won't heat the house all the way to setpoint, but mechanical failure of a modern geo system should be rare.

    As for service size, 10 vs 15 kw might just make the difference betwen 200 and larger.

    Contractors on the ground are nearly always a better source of advice than we on the net. Our role should be to guide you interms of what questions to ask. Occasionally we expose an outright hack, scammer, or charlatan, but that's the exception, not the rule.
  4. cdhand

    cdhand Guest

    I am not a pro but I have a 3100 sq. ft. house with a 3&2 ton waterfurnace I also have a 15 kw aux. heat strip on the 3 ton which I found I don't need or want so I cut it off at the dip switch that way it will not come on each time that I set back the temperature. I have 200 amp. service. You will love your system but the size of your loop does not sound good to me as I have 6 200 ft. wells. I also don't like the way your installer said that this was cutting edge sounds to me like he don't believe in what he sells. These systems are wonderful if they are put in right. When mine was put in they left out the back flow valves that must be installed when 2 units are put on the same line and they left in the shipping bolts on the compressors I was also told that they had put in antifreeze when they had not put in a drop. Because I have read up on these systems I now have a great install and I could not be happier with my systems they use very little electricity make very little noise and everything is inside out of the elements so it should out live me I just don't like to think about that. One more thing because the fan runs 24 hours on a very low speed every room will be the same temperature my duct work is old and not perfect but the system makes up for it.
  5. rw1995

    rw1995 Member

    I just converted to a 4ton Waterfurnace and kept my 200A service without any issues. I needed 6 open spaces total (two 240V breakers for the WF, one 240V breaker for the water heater)

    I'm not sure of your original setup, but I was able to eliminate the 240V outdoor AC unit breaker and 120V breaker to the old NG furnace, creating 3 open bays in the breaker panel. I created the other 3 spaces from using tandem breakers.

    The units do not pull a great deal of amps anyway, especially if your auxillary is not running. I used the 10kw strip for my unit, which has never seen any current as my loops have handled the midwest winter fine and I have since turned it off anyway.

    The loops as the others noted seem short. I went horizontal, but I had vertical quotes of four 180' wells, 720' total for the 4 tons.
  6. wrice3

    wrice3 New Member

    I agree

    that does not sound like enough loop. And anyone who has been here longer than a day can tell you the hazards of being short looped:D
    I have 3 x 250 ft vertical loops, 1.25" pipe, for a 5 ton WF. Only used aux heat when the outside temp was -5 F to keep the house at 69 F. Have since turned it off with the dip switch and have not used it.
  7. AndyF

    AndyF New Member

    I'm in Indiana, we get pretty cold here in the winter, with summers in the low 90s. I have a 5 ton WaterFurnace Envision with 5-150' wells that works out to 300' per ton of vertical loop per 150 feet of bore. Without running any kind of analysis, I would think that you should have at minimum of 600' of vertical bore, but things like soil composition and heat transfer capability of the ground can influence the depth of the bore.

    I also have a 200 amp service in my house with an 80 gallon electric water heater and a 15 KW strip heater. (The panel is very full but it works well)
  8. geo fan

    geo fan Member Forum Leader

    The first thing I thought of with the service size was the hot tub
    they can draw allot of juice
    My recomendation would be if the electritian thinks your close and you dont trust him get a second opinion , if you do trust him go with the up size at install it shouldnt be a bank breaker , if you find you have to upgrade the service down the line it would be much more expensive
    I would want extra juice in case I wanted to add something down the line
  9. robertbout

    robertbout New Member

    earthlinked system in Ct.need fine tuning ??

    I have a 6 ton system for a 2700 sq. ft. single level home and I have found my electrical bills rather high 550 and 450 starting in jan of 09.
    foam in the walls r 20 and foam in the ceilings r 30 with all energy efficient glass.
    Are there any adjustments or things that I need to look at to make things more effecient? or are these typical for the ct, area.as it was very cold.
  10. Looby

    Looby Member Forum Leader

    The $$$ don't tell us much. How many kWh per month?

  11. geo fan

    geo fan Member Forum Leader

    2300kwh -2800
    is that the whole bill or submetered
    welcome to the land of 19 cents a kwh
    thats not earthlinked thats deregulation ( thanks dpuc )
    check out alternitive generation
    CT Energy Info
    here is a link that should save you around 50 bucks a month
    its legit I am many things but a salesmen I am not
  12. robertbout

    robertbout New Member

    2422 kwh

    thanks for the response 2422 was for feb which was pretty cold.
  13. robertbout

    robertbout New Member

    electrical usage

    I looked at the link and could not see how I could save the monies you referred to. Any help would be appreciated Thanks
  14. geo fan

    geo fan Member Forum Leader

    when you open the link
    it asks to select your electric rate
    scroll down to the rate you currently pay ie CL and P rate 1 "standard'
    it then brings you to a savings calculator
    with a list of generation providers on the left
    description of offer in the center , offered rate , and calculated savings
    by entering the kwh usage at the top the savings is adjusted
    with 2400 kwh used PPU offers savings of 44.69 over cl and p rate 1
    by clicking the graphic of the generation provider on the left it brings you to there website CT Energy Info
    once one the appropiate website signing up takes 5 min. ( have your bill handy
    If you find a provider you like but cant get to there form let me know I will be happy to post a link for that to

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