Page 2 of 3 FirstFirst 123 LastLast
Results 14 to 26 of 28
  1. #14
    Join Date
    Jun 2001
    Location
    Louisville, KY
    Posts
    12,181
    Horse poop. Let 'em run.
    Perhaps you should have read the instructions before calling.

  2. #15
    Join Date
    Oct 2006
    Location
    Emerald Coast, FL 30.1N 85.8W
    Posts
    681

    Personally, I'd like to see NG used more as auxillary heat

    HP's should have mulit-stage electric heat strips for auxillary heat below the balance point of the structure.

    I"d personally like to see multi-stage natural gas (NG) incorporated as the auxillary fuel in HP's, but so far I don't see it happening -- a lot of customers complain of lower heat temp of HP's.

    I see mostly AC & Gas Heat in north Atlanta suburbs, and HP's with electric auxillary in most other southeastern locations.

    Typically HP's have COP's of 1.5 at zero degrees ambient, but the btu/hr output crashes around 45 degrees ambient, and the HP just can't cut it.

  3. #16
    Join Date
    Apr 2005
    Location
    Kingston Ontario Canada
    Posts
    1,210
    Quote Originally Posted by gary_g View Post
    This statement is wrong. Electric resistance is never cheaper than a heat pump (except in arctic climates). The btus that the heat pump puts out drops as the temperature decreases, but so does the power consumption of the compressor.

    At 15F, my heat pump has a COP (Coefficient of Performance) of 2.46. This means that 2.46 kw of heat are produced for every 1 kw of electricity consumed. It is basically 246% efficient at 15F.

    Many people do not want their compressors running constantly because of wear and tear, but that's a different issue.
    Great point, Gary G!!! Heat pumps with aux heat strips, especially if they are staged heat strips should always run no matter what the outside temperature. I'm also concerned with heat pump compressor running constantly when I first had the heat pump installed. But I finally got it squared away in my mind that heat pumps are not like furnaces (because most are oversized) and need to run lots. This is why I keep the set point temperature on the low side during the day and set back only 2 degrees at night.

    thorton
    ______________________
    If common sense is so common how come so few of us have it!

  4. #17
    Join Date
    Dec 2007
    Posts
    6
    you need to check out the carrier infinity duel fuel systems they will let you use gas as a aux heat they are comeing out with a new three stage gas furnace that will work good

  5. #18
    Join Date
    Aug 2007
    Location
    Rochester, NY
    Posts
    170
    Quote Originally Posted by bigrob36 View Post
    you need to check out the carrier infinity duel fuel systems they will let you use gas as a aux heat they are comeing out with a new three stage gas furnace that will work good
    But with duel fuel it is an all or nothing proposition. You can't run the fossil fuel furnace with the heat pump due to the higher discharge temps boosting the Refrigerant pressures.

  6. #19
    Join Date
    Nov 2007
    Location
    Livermore, Ca
    Posts
    163
    I new to HP's also. Some of my first info stated that run times may be very long as outside temps drop.

    This is my third season. This month, the second stage has not been used on purpose. Maybe I'm a glutten for punishment but I'm looking forward to my PG&E bill.

    The first year was terrible. Everytime one of us felt a chill, up went the
    T-Stat to bring on the second stage. The highest bill was $400. No more of that. Trying a set it and forget it approach and ( Let 'em run )

  7. #20
    Join Date
    Dec 2007
    Posts
    6
    we duel fuel our units all the time the heat pump will not run when u are in defrost or you get below your aux lock out temp to operate a duel fuel unit well cost you less than a regular heat pump

  8. #21
    Join Date
    Oct 2006
    Location
    Emerald Coast, FL 30.1N 85.8W
    Posts
    681

    that's what i'm saying

    As far as I know, this statement is true -- can anybody correct this statement?

    Quote Originally Posted by ebierley View Post
    But with duel fuel it is an all or nothing proposition. You can't run the fossil fuel furnace with the heat pump due to the higher discharge temps boosting the Refrigerant pressures.

  9. #22
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,060

    Smile

    Quote Originally Posted by emcoasthvacr View Post
    As far as I know, this statement is true -- can anybody correct this statement?
    The only time the heatpump and the fossil fuel will run simultainiously is during the defrost cycle. That is not to say that they will not switch back and forth according to lock out temperatures.

  10. #23
    Join Date
    Sep 2001
    Location
    Vancouver Canada
    Posts
    996
    Agreed, heat pump will almost always be more efficient than electric strip. Try letting the Tstat control when aux comes on. Lock out the outdoor probe and see how well that works. Aux should only come on when pump can no longer keep up to heat loss.
    "Go big or Go Home"

  11. #24
    Join Date
    Dec 2006
    Location
    Middle Tennessee
    Posts
    11,347

    *

    Quote Originally Posted by bigrob36 View Post
    we duel fuel our units all the time the heat pump will not run when u are in defrost or you get below your aux lock out temp to operate a duel fuel unit well cost you less than a regular heat pump


    what?



    .

  12. #25
    Join Date
    Dec 2007
    Location
    Clearwater, FL
    Posts
    92

    Equipment Models

    I'd be curious to know the model equipment you have. If lock outs are set then lower them. The charge of the system could be off. I would hope you would have a staged electric heater if the setting is that high. Mine wouldn't turn on unless 1) time on stage 2 heat pump expires or 2) defrost or 3) I manually set the t stat for elec heat. I have limited expierence with Nordyne equipment, Do they use TXV's at the outdoor unit? Good Luck

  13. #26
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,912
    His system may have been sized to the A/C load, and need to bring the strips on a little sooner.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

Page 2 of 3 FirstFirst 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event