Forced Air Heat Question

Hi-



I have a old Forced Hot Air wall Furnace in a unit. The question

I have is that it is vented by duct to the roof, but it also has a hole cut out in the floor underneath it that opens to the crawlspace. Is that hole to the crawlspace necessary? I would like to cover it if not. What do you think?
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Comments(6)

  • mikejaquish9th December, 2005

    Check to be sure that it is not the cold air return route.
    If that is where the majority of cold air loops back to be reheated and you close it off, you will starve the blower for air to push heat.
    Strange as it seems, some old-timers would drop cold air into a basement or crawl rather than invest in ductwork.

    Quote:
    On 2005-12-08 14:27, d_random wrote:
    Hi-

    I have a old Forced Hot Air wall Furnace in a unit. The question
    I have is that it is vented by duct to the roof, but it also has a hole cut out in the floor underneath it that opens to the crawlspace. Is that hole to the crawlspace necessary? I would like to cover it if not. What do you think?

    [addsig]

  • d_random9th December, 2005

    [ Edited by d_random on Date 03/03/2006 ]

  • d_random3rd March, 2006

    Here is a picture of the forced air wall unit.



    And inside the unit the arrow points to the hole that cuts thru the floor, down to the crawlspace.
    Can I cover this hole w/o impeding the units ablity to push hot air?

  • d_random6th March, 2006

    bump

  • IBuyHousesInc6th March, 2006

    How the hesk did you get pictures posted
    [addsig]

  • GURU16th March, 2006

    Hello there..

    I was a heating / air tech for 5 years up in lake tahoe when I was younger. I find it funny I am reading about this on here. It brings back many good times! To answer your question.. The reason that hole is there is to provide fresh air for the pilot lite to stay on. Depending on the size if the living space we would not have a hole in the floor. Obviously in order to have a flame you need to have oxygen. If the room is very small and is sealed well it is necessary for the hole or the pilot lite will eventually go out due to starving for oxygen. You can see that on the bottom of the unit there are louvers on the grill. As long as these are not obstrcuted and can allow the necessary air in for the gas valve when calling for heat you will be fine by closing the hole. I would just drill a 1/2 hole for the gas line and stat wire and there would not be any other ventilation on new constrcution. It is the same concept if you have a water heater in a closet. You will notice that there are upper and lower fresh air grils on the door or ducts through the floor and ceiling 12" off the ground and 12" off the ceiling. This again is to make sure the flame stays lite and has enough oxygen to work properly. In your case I would cover the hole and not worry about it unless you are in a very small room with no circulation and source for oxygen. Good luck and thanks for bringing back the good memories of tahoe.

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