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My gas fireplace

james_6 Member Posts: 49
dont worry bout closing off your fireplace. i do it every year and im still alive! bad advice and no reason why



  • james_6
    james_6 Member Posts: 49
    My gas firplace

    I have a gas fireplace that when not in use has alot of cold air coming out of it. The glass doors don't close very tight, I want to close off the air space. I put 1" foam insulation to block off the doors. I put it inside the fireplace. Is this safe to do?
  • Floyd_2
    Floyd_2 Member Posts: 52

    And if you have that much of a down draft you better not be there when it is running, or worse yet go to sleep with it on....you'll wake up dead.....

    Find out why your pulling air in.

    Hope your still alive to get this....

  • Dale
    Dale Member Posts: 1,317

    If you have regular doors you either have a converted wood fireplace or one designed for natural draft. What's happening is that your house is negative in an air pressure sort of way compared to the outside and the air the house needs to balance comes in where it most easily can, ie the fireplace doors. I guess I would seal up the doors or get a better set or a sealed gas fireplace insert.
  • Mark Hunt
    Mark Hunt Member Posts: 4,909
    Just don't

    light it!!

    If you want to block it off when it is not in use, fine.

    You will find out soon enough if you forget to take a piece of foam out.

    When do you notice the "draft" coming in? Is this fireplace vented into a pre-exisiting chimney, or was the chimney built for the gas fireplace?

    Mark H

    To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"
  • james_6
    james_6 Member Posts: 49

    mark, i believe this chimney was built for the gas fireplace. Would it be very hard to change it over to wood burning? how would i be able to tell if this was wood and changed over to gas? would it change the dynamics of the pressure in the home? or should i say which is better as far as pressurization of the home?
  • Mark Hunt
    Mark Hunt Member Posts: 4,909
    Well John

    If the chimney was SPECIFICALLY built for the gas fireplace, newer construction, you can't burn wood in it. The chimney would melt!

    Gas fireplaces are pretty populer now, have been since the 80's building boom.

    As I said, you can block the fireplace off when you are not using it, in fact, there are inflatable plugs that will go into the flue outlet to make an air tight seal. They also have a BIG RED FLAG that lets you know that it is still in place and that starting a fire would be a bad idea!!(Wink, WInk!)

    I asked those questions because I run into situations like yours all the time as a home energy auditor.

    Plugging that hole will definately change the air infiltration into your home. Whether it will be a good change or not would have to be determined with testing. If air is coming in through THAT hole and you plug it, it will have to find another hole to come in through. That hole might just be the chimney that your water heater or furnace vent into. That would be bad!

    If you live in New York, go to www.getenergysmart.com and look for a qualified analyst in your area.

    If not, try your state energy agency or call around until you find someone that can perform a blower door test on your home.

    If you are in New York, give me a call.

    The number is on the link!

    Mark H

    To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"
  • james_6
    james_6 Member Posts: 49


    this home was built in the early 50's. Maybe it was an original wood burning fireplace. it is covered in limestone. The thing i dont like about the gas fireplace is it is not a good conductor of heat. the heat seems to just go up the flue. thanks for the hints. i am going to look for the inflatable plug!

    thnaks John
  • Steve Ebels
    Steve Ebels Member Posts: 904
    Here's why

    And it's not bad advice. If you have air coming down your chimney it is going against one of the laws of physics. The particular law I'm refering to is the one that states, Air which has a higher temperature is lighter and therefore will seek to rise. The air in your home is typically warmer than it is outside this time of year so if he opened his FP doors he should feel a draft going up the chimney. Also, the "stack effect" which makes chimneys work is apparantly being overcome by something going on in the house.

    Let's assume a couple of pretty standard things here.

    1. This guys house has a furnace or boiler in it.

    2. It has it's own chimney flue

    3. The exhaust from said furnace or boiler must exit the building or our friend wakes up dead. (pretty standard stuff, right?)

    Now, that being said and understood hopefully, here's the scenario likely to occur.

    Seeing that his fireplace chimney is acting as a makeup air opening for the home, plugging it would cause the negative pressure in the home to be compensated for by some other opening. The next most logical choice for allowing air into the house would be the other flue of the chimney containing the flue gases from his water heater, furnace or boiler. If that flue becomes the source for makeup air when one of the appliances is burning, where does the flue gas go???

    Right! directly into the guys house. Can we see where this would be a bad thing?????
  • Floyd_5
    Floyd_5 Member Posts: 418
    Thanks, Steve...

    I didn't feel that I had to defend myself, because I am confident in what I know is right....Thanks for the explainantion.
    Also, another scenario that I can envision is the case where the wife wants one of those neat pop up Jenn-Aire or equivalent ranges with the hod the moves more air than the central vac and ususally about as much as a small shorched air furnace....
    BIG problem... they forget that this "smoke vac" has got to pull air from some where.... or they put the biggest baddest bathroom vent in to vent the steam......

    There are many ways to do ventilation WRONG AND DANGEROUS!!!
    But big box and even many supply houses insist that joe homeowner can do it hisself.....

    Ya......he can also kill his family.....

    If only it was reported how many just make it out in the nick of time or end up in the hospital with o2 masks on...

    It's staarting to get cold ... we can't be too careful...
    watching this site and becoming more aware of what CAN happen has sure been sobering to ME!!!! The lives of others are in my hands......I cannot take that responsibility lightly.

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