Poked my noggin in the fireplace and peeked up the 12"x12" flue,, frost all the down to the throat. I know this is expected when the weather gets into the negatives here in MN. Any advice on how I could deal with this when I start my weekend, just for looks, make the wife feel fancy fires ? Thanks
clay flue frosting up real bad
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I'll bet you can imagine how much cold air is being sucked down the chimney into your home!. Pretty sure I could of hung a wind chime off my fireplace and listened to the music all winter! Other than install a insert or stove I don't know of a fix other than blocking off the flue. I couldn't hardly burn my fireplace if a cold air inversion set in.
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Is it frosting up while burning? If this is an exterior chimney and being that large there is a possibility that it can't overcome the differential and it not drafting. Smoke has a lot of water vapor in it. If it's rising and cooling before it exits the flue it can freeze. Not a safe situation as all the CO is not exiting either.
Not while burning.. It is a newly re-constructed masonry chimney, it drafts great. I have less than 20% moisture in my wood. draft is no issue.
me too. just preparing for it to rain down on the kindling for the first few minutes
qyota
Member
Sounds like the air moisture in your house ("humidity") is quite high. Frost represents water that is coming from your house, up the flue, and changing to ice. Are your windows covered in a thick layer of frost as well?
some windows have maybe a 1-2" wide strip of foggy/water glaze (not ice). my weather station says humidity is in the low 30's%. is that high?
qyota
Member
Is that measurement taken in the same room as the fireplace? Low 30's RH isn't bad. 30 is about where you want it over the winter. Any lower and you have a very dry environment, and plenty of static electricity. I was hoping you'd say 50% or higher, which would explain the flue frost. The moisture is coming from somewhere, and it's not likely coming from outside this time of year. Perhaps there is latent moisture from the new(ish) masonry job? That seems like a stretch, though.
hmmm, now I'm really curious. the unit is in the kitchen (open floorplan) 20-sh feet from fireplace. we've had a couple few fires since it's completion. Mason left of Halloween, we let the job cure, had our first small quick fire on 11-20...
maybe a top sealing damper cap? but not if its coming from inside obviously.......
Does your wife bake allot in a gas oven? At minimum you should have a chimney cap, a cap/damper seals airtight at the top. Any other flues in chimney?
Does your wife bake allot in a gas oven? At minimum you should have a chimney cap, a cap/damper seals airtight at the top. Any other flues in chimney?
blacktail
Minister of Fire
She does love to bake. And there is a 9"x12" flue next it, for the potbelly stove that's downstairs. I have experienced some cross drafting... I only burn on the weekends
could possibly be gas fumes drawingup fireplace flue and condesing in the flue. ikinda doubt it with damper closed but ive seen stranger things. if its an inside chimney its much more likely. gas produces a ton of water when it burns!
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