Results 1 to 11 of 11
  1. #1
    Join Date
    Mar 2006
    Location
    WV
    Posts
    21
    I've had some great feedback here to help us zero in on an A/C and heat pump solution (Carrier Infinity in particular). We have supplemental heat in both hydronic fin-tube radiators, and hydronic radiant floor heat (but just in 3/4 of the house -- the front half, second floor will only have heat pump).

    What we were wondering though while we have all the ceilings (and some walls) torn out is whether we should run boiler water lines up to the attic with the potential to add hyrdronic aux heat to the heat pump.

    Would this be worth it? Does hydronic aux heat really work? My husband said he's heard otherwise (from the radiant floor material supplier).

    Thanks in advance for your help!

  2. #2
    Join Date
    Apr 2005
    Location
    NE PA
    Posts
    698
    Hydronic aux heat works very well. The water heat exchanger must be sized correctly, and the lines to the air handler should be well insulated, but it is a very good alternative to electric strip aux.

    paul

  3. #3
    Join Date
    Feb 2006
    Location
    RedWing MN
    Posts
    110

    Cool

    Works really well, can almost compare to an oil burner for supply air output. One that I was involved with used infloor heat in the basement and HW coil in the air handler for heat he also had the A/C coil in the same air handler. The house is insulated real good and the home owner spends a lot of time in the basement (its a walk out). The radiant heat keeps the house comfortable with out cycling the forced air part because the heat is rising up the open stair way.

  4. #4
    Join Date
    Mar 2003
    Location
    PA/DE area
    Posts
    1,535
    If watercoil in attic make sure you have freeze protection,I would say that Carrier SMART HEAT might be a safer and cheaper way to go. The strips are staged and since heat rises it will rarely need back up.
    It's NOT the BRAND,it's the company that installs it!!!!!

  5. #5
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,370
    It works fine, sounds like your radiant guys are trying to get him to go with radiant back up on the second floor also.

    When you say aux heat for the first floor is baseboard, and radiant, do you mean at 40, or 35° outdoor the hydronic system takes over and the HP is locked out.

    Or your going to let the heat pump blow out cold air during defrost.
    Contractor locator map

    How-to-apply-for-Professional

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

  6. #6
    Join Date
    Mar 2006
    Location
    WV
    Posts
    21
    Or your going to let the heat pump blow out cold air during defrost.
    Yikes ... I hadn't really thought that through. We definitely don't want it to blow cold, but without any heat pump assist the 2nd floor front rooms won't stay warm. Sounds like we definitely need the hydronic aux. Thanks.

    heatpump guru, the attic is finished (heated) space with insulation in knee wall and roof but not between coil and living space. So I think we're good on that.


  7. #7
    Join Date
    Feb 2003
    Posts
    1,996
    If you're gonna rip out ceiling and walls, why not just put in some baseboard or panel rads up there and make it another zone? I would just avoid running water lines into an attic, only as a last resort. By the time and trouble of buy a heating coil for the air handler and adding anti-freeze, I don't think some BB or a panel rad or 2 would cost too much more. Safer to keep hydronic lines in conditioned space and it's beter comfort. If you have walls ripped open already the labor can't be that much more. Your supply registers will probably be in the ceiling right? Lousy location for heating. Just use the HP in spring and fall. With the stories I'm hearing that some electric utilities are putting in for big rate increases this year, I'm starting to doubt if going duel-fuel is worth it.

  8. #8
    Join Date
    Dec 2005
    Location
    Current whereabouts unknown
    Posts
    640

    i agree with guru

    carrier SMART HEAT package is probably the most practical way to go. Best resistance heat available, in my opinion. For the area it's serving, the AUX shouldn't run that much anyway. SMART HEAT is probably the best option, in the short term as well as in the long term.
    BTW, I sell Trane equipment and I wish Trane had a system out there with control comparable to Infinity. Infinity is a sweet setup.
    It matters not how strait the gate,
    How charged with punishments the scroll,
    I am the master of my fate:
    I am the captain of my soul.

    -- William Ernest Henley

  9. #9
    Join Date
    Mar 2006
    Location
    WV
    Posts
    21
    If I don't go with any aux heat, just the supplemental radiant and radiators (installing radiators to complete the coverage), and turn off my heat pump when it gets below 30 degrees, then I'll lose out on the use of the humidifier that we're adding when I need it the most. This is the whole reason we even added a heat pump to the design.

    I'm an engineer, but it's been a looooong time since I've taken any heat exchanger classes. Is it true that the ability for the heat pump to perform is only dependent on outside air temp, and not the delta temp demand placed on it? In other words, is it true that there is no heating benefit, to complement the rad heat, to running the heat pump when temps drop to 25 degrees? Will it really blow cold air?

    On the SMART HEAT option ... I guess I'm shying from installing resistance heat because we own a perfectly good boiler. We're already having to install an H20 heater for the radiant floors alone. I'm trying to put the boiler to use as the supplemental heat rather than do more electric.

    Frankly, we were only looking at A/C and planning on using only hydronic heat. But then when we started considering optimal humidity control (both up and down -- I've got awful nosebleeds in the winter), the heat pump + humdifier seemed the way to go. Now I'm chasing a solution that integrates it while still making sense. I really love radiant heat, but am willing to have air blowing around if it's going to humidify the air for us in the dead of winter.

    It seemed so simple in the beginning. Just install me some A/C so I could keep the mold off my stuff. Then my needs started to creep ...


  10. #10
    Join Date
    Feb 2003
    Posts
    1,996
    I think a hydronic heat system needs very little extra humidity if the house has little air infiltration. Cooking, showering, laundry, etc should be adding enough humidity. Aprilaire makes an in-wall mounted humidifier that could do a whole house. Why bother putting moister into a duct system to create mold. You still must keep humidity levels under 40% or you'll get condensation on windows and cold walls. Idea is too keep the dry outdoor air out. I saw a humidity imporvement in my house this winter when I installed a boiler with fresh air intake. Stopped the boiler from burning all the indoor moist air which makes the house go neg air pressure and sucks in cold dry outdoor air.

  11. #11
    Join Date
    Mar 2006
    Location
    WV
    Posts
    21
    johnsp, thank you for clarifying for me that I am trying to solve a problem that I myself created! By eliminating the heat pump altogether, and leaving a few extra radiators, I can save big bucks and some headaches. It's been awhile since I lived in a radiant heat house and I'd forgotten how my nose never bled then. Again, thanks!

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