Q: Jason, I have a vented Majestic fireplace. We do not use it, but it is letting tons of cold air into my house. The vent on the outside of the house doesn't seem to have any sort of damper on it whatsoever... so closing that is not an option. Right now we have the gas turned off & a blanket over it.
Would a Chimney Balloon help with this? How exactly would we get in to measure the hole? How do we get into the part that has the gas logs?- CG
A: Dear CG, By a few hints in your question, I am assuming that you have a direct
vent fireplace not a gas log fireplace. You say "vent to the outside",
does that mean the vent is a PVC pipe that goes directly through the
exterior wall, not out the roof like a chimney?
If it vents through the wall you definitely have a direct vent fireplace.
The good news is, that direct vent gas fireplaces (unlike vented gas logs) generate heat efficiently when running. The bad news is, if the fireplace installer does not take care to insulate the fireplace install correctly it will let in a great deal of cold air when dormant.
If you have not had the original installer over to look at the problem I would try that first. If they stonewall you about it, call an insulation contractor that is forward thinking enough to work with closed cell foam.
You see, a fireplace installer will sometimes slap in a fireplace and think "good enough" but an insulation contractor has a different way of thinking. He will look over an install and consider how it effects the homes envelope and how he can make an install both safe and tight.
I'm sorry but a chimney balloon will not help you on a direct vent fireplace since the firebox is a sealed unit and you can't gain access to the vent flue and that vent flue is just a small pipe through the wall anyway. - Jason