Heating the floor crawl space!

Discussion in 'Shop Talk' started by r.h. in okla., Dec 26, 2005.

  1. How safe and econimacal would it be to heat the crawl space underneath the floor? I'm thinking why couldn't I heat the crawl space up and that would radiat the heat evenly all throughout the house. I shouldn't have to worry about my wife's cold feet when we go to bed!

    Could I place a portable electric heater underneath the floor and rig it up to a thermostat located in the bedroom hallway? My crawl space is two cinder blocks high and my small house is almost 900 s.f. Right now I heat with a woodstove only, located in the living room and it gets really cold in the back bedrooms.

    Also, if I could heat the floor crawl space in the winter to keep the house warm, could I cool the attic down to keep the house cool in the summer time?

    Thanks for any input/advice/tips, etc.
  2. Ken Scharabok

    Ken Scharabok In Remembrance

    May 11, 2002
    If the crawspace is ventilated, as it should be to avoid condensation build-up, you would essentially be wasting your heating money. Can you put a temporary block in the vent area(s)? On attic heat building, I saw one place where the owner had installed a fan in the ceiling of the garage to blow air up into the attic - which vented by the eaves. On a timer for the hottest part of the day. Logic was it helped to keep attic cooler then, but I suspect additional insulation on the attic floor and air spinners in the roof would have worked just as well.

  3. Richard6br

    Richard6br Well-Known Member

    Nov 29, 2005
    Is the crawl space insulated? If not, thats where I would spend the money. Insulate the crawl space with fiberglass batt insulation. Make sure that the vapor barrier is placed up toward the living area. Install a wire mesh at the bottom to hold the insulation in place and to keep out vermin. I assume that the crawl space is ventilated. If not do so.
  4. ttryin

    ttryin Well-Known Member

    Apr 10, 2005

    Ever since I received the first utility bill for an electric heater the landlord, without informing me, put in the crawlspace of a small rented house, to today where I have a small crawl space over a bathroom addition, I've been working on this subject. Answers seem to change for house design, location etc. It's a little work to read through it, but I have been able to improve living spaces and lower utility bills, and do the work myself. What worked for me might not work for you. Try www.buildingsciences.com, with pictures and how to suggestions. Or try http://www.buildingscience.com/sitemap.htm

    Good luck. T
  5. WanderingOak

    WanderingOak Well-Known Member

    Jul 12, 2004
    New York
    When I bought my house, the pressure tank, etc, were in the crawl space, and there was a heating vent in the ceiling to keep the 'water room' warm. The pipes never froze, but the bathroom allways did have a cold floor. Also, my crawlspace can not be completely sealed, so the heat was a critter magnet in the winter. I would have 'possums and racoons down there, and meanwhile my own cat would spend time down there as well. I am sure she was collecting a cover charge and selling catnip :D .
  6. mistletoad

    mistletoad Well-Known Member Supporter

    Apr 16, 2003
    Southern Maryland
    I have seen where the radiant floor heat can be installed in the crawlspace rather than the subfloor, but I don't know if you could insulate below it or even if you would need to.
  7. Countrybumpkin

    Countrybumpkin Well-Known Member

    May 12, 2002
    My old neighbor, a West vigrinia hillbilly, as he liked to call himself, built a house by me, and put in 2 4" pvc pipes, going from attic to crawl space...in the winter, he took a duct fan, and put it in 1 pipe, facing towards the crawl space, and used the sun-warmed attic air to warm his crawl space, and the other pipe acted as a vent to take the cooler air up into the attic to start the process over. He blocked his attic vents to do this, which might not be the best of ideas, but his floors were always warm when you went over to visit him, so he must have been doing something right!
  8. Janon

    Janon 993cc Geo Metro

    Aug 25, 2002
    Southern Ontario CANADA
    I'd agree with the others. Your crawl space should be insulated and ventilated. Heating a ventilated crawl space is not accomplishing much except draining your wallet. And if your crawl-space is not ventilated, you'll have moisture problems.

    With a crawl space and with most types of heating, and even with insulation, your floors will still be somewhat cold in the winter. In-floor radiant heat would be a good choice for crawl-space type homes.

  9. uncle Will in In.

    uncle Will in In. Well-Known Member Supporter

    May 11, 2002
    Blow some heat down the hallway with a fan. Wear shoes and socks until bedtime. Electric blankets are oh so cozy in a cool room.
  10. Jennifer L.

    Jennifer L. Well-Known Member Supporter

    May 10, 2002
    New York bordering Ontario
    I have a whole house fan installed in the ceiling of my house that takes air from the interior of the house and blows it into the attic in the summer time. The attic air exhausts out of the sofits and takes the heat build up with it. A well insulated attic will not exactly keep the heat out of the house. After days and days of high temp days in the summer, your attic insulation heats up, too. I only run the fan after the outside temperature in late afternoon is lower than the inside house temperature and it gives a nice breeze through the house that is very nice.

    I don't know about the heated crawlspace, but if it's not insulated it would be a waste of heat. Might as well put the heat where you want it and bypass the crawlspace.