BRRRR fireplace making it colder
here’s the situation. 75 year old house in Northeastern IL. 2 fireplaces that were woodburing, but have been converted to gas log.
The one that is giving me trouble has a TON of cold air coming out of it. Thr problem is two-fold. The damper (I assume original) doesn’t always close so well. It seems like the points that the flap part are supposed to pivot on can slip out of position, so when you flap it closed, it doesn’t seal very well. This is a pain, but when it cools off, I can fix it by hand. I have been told that replacing it would be a huge job involving ripping apart a lot of masonry, so I am resigned to living with that.
The problem I think I can fix pretty easily is that there are gaps around the damper mechansim where the cement that it was installed in has broken away. The damper assembly is not lose at all, but there is a lot of air coming in around it.
What would be a good way to seal this up? Should I mix up a small batch of cement and try and patch around it? I would love to use some sort of expanding sealer, but I can’t imagine that would be safe to do in a working fireplace. Is there a product like this that is fireproof when cured?
I have an electric space heater that we put right in front of it to take the chill off, and it is in our downstairs den, so we are not there all day, but it is about to become a full fledged home theater so I don’t want to need a parka down there all winter long.
I could make an insulated board to cover the fireplace opening when we are not having a fire, but that seems like an ugly fix to me.
Any input will be appreciated.
ar
Edited 12/10/2006 5:42 pm ET by ar7499b
Replies
I had one of these chimney top dampers installed, ($425.) by the "We clean any chimney for $20.00" guys. Have to say it works well. My damper was broken (missing). The only thing is that you have a cable running down the flue and termininating on the side of the firebox.
http://www.fireplaceessentials.com/c4/Top-Sealing-Dampers-c95.html
The current issue of FHB has an article on installing the chimney top dampers.
Not unusual. The damper possibly is not closing because that is the way standing pilot gas log units are supposed to be installed. The damper is not supposed to close all the way because of the standing pilot light. Haven't used a non pilot light unit so don't know if that is a requirement for that type.
Gas log in fireplace is usually a costly item to operate. Most of the heat goes up the chimney and to replace that draft up the chimney, is cold air entering into the house from wherever it can. The cold air that comes in must then be heated and the little bit of radiant heat you get from the fireplace just won't do it.
ar7499b
You are aware that having a fireplace burning causes the house to be colder aren't you?
Mythbusters did a segment on it and documented the fact. They also did a good job of explaining what is happening and why..
So if it's not burning the fireplace makes things cold, and if it is burning it makes the whole house colder!
I can expalin if you are having trouble accepting it, perhaps not as well as they did but hopefully enough so you'll understand what an energy sucker fireplaces are..
Not all fireplaces - masonry heaters and rumfords do far better.
We had a masonry heater & it heated 3,000 s.f. quite well by itself.
http://mha-net.org/
Treat every person you meet like you will know them the rest of your life - you just might!
Brian,
I really can't say, I've heard the claims for Rumsford fireplaces and read some claims for masonary heaters. I do only know what they showed on Mythbusters that a fireplace in use made the rest of the house cooler.
Now to show just how stupid I am, I intend to put a Rumsford fireplace in the living room, provide a fresh air intake thru the ash grate, close off the front with glass doors and hope for the best. I'll incorporate some of the features of masonary fireplaces in that the heat from the masonary will be blown into the room. In addition the whole fireplace will be inside the building's insulation envelope not half in half out as is so often done.
I simply love watching a fire burning on a cold wintery day and having spent a little over a year without mine even if it's inefficent I want one!
Glass doors reduce the efficiency of Rumfords, from what I've read. Evidently the glass does interfere with the radiant energy emitted from the firebox.
basswood,
Yeh, I've understand that as well but if I don't glass off the firebox heated air from the fireplace will go up the chimney. So the yield will be lower but the loss will be less, at least that's my thoughts..
Well asthetics are enough reason for a fireplace, so go for it, and fresh air is a good idea with modern house tightness...
Did I read you timber framed your house? I am thinking of framing a barn soon - any advice on finding timbers and how long it takes to cut and assemble? (I have the Benson books)
Treat every person you meet like you will know them the rest of your life - you just might!
Brian,
I love to talk about timberframes.. I too have most of the Benson books (well actaully all of them )..
Finding timbers is or should be a piece of cake and cheap besides..
I have a double timberframe with bents every 4 feet.. black walnut on the outside and white oak on the inside.
50,000 bd.ft of hardwod and I doubt I spent $20,000 on wood!
Some advice, don't do as I did.. !!
I dried all of my tmbers for years before I planned them and cut them to size etc.. it takes 10 times as long wears out blades and well, me! Put them up green and accept the resulting checking if you heat the interior before they dry out.. (if it's a barn will it be heated?)
To budget your time, assuming that you buy the right tools and are dedicated about working Plan on each green timber taking about an hour and each dried timber taking about 10 hours.. (yes, ten!) You won't be that fast at first but you will quickly gain at the end!
I've installed two chimmney top dampers in my house and they're not expensive ands its easy to do. Its the kind that the chain comes down from the damper up top the chimmney through the chimmney and is affixed to the sidwall at handsds reach to be pulled when you decided to open or close it. It really is very easy to install and inexpensive all things considered.
Theres an article in this FHB about just this,
I have dreamt of an open world, borderless and wide... where the people move from place to place, and nobody's taking sides.. http://www.yusufislam.com
http://WWW.CLIFFORDRENOVATIONS.COM
I have twelve (12) of the spring-loaded chimney top dampers, with the cables running down into the firebox.
We have an old house that had no dampers
They work super well; one thing we do is open up the hook on the little coiled wire handle so we can remove it during a fire so it doesn't get sooty.
Forrest
Thank you all for responding.
Actually, the first place I called suggested a chimney top damper. I will consider this route, and definately will read the article tonight. The chimney stack is actually for both fireplaces, (with seperate shafts of course), so I don't know if that will add a lot of cost to the install or not, but I imagine they have a product for just that situation.
qstringe - This fireplace has no pilot, so there is no need to keep an open flow when not in use.
frenchy - I know that these suckers are not efficient sources of heat, but they don't have to be like leaving a window open. The other fireplace does not let much cold in at all. You have to put your hand right under the damper to feel the cold air. With the troublesome one, you can feel the draft as you enter the room.
Everyone seems to be in favor of the chimney top damper, so I will give that some serious consideration, but in the meantime, if anyone has a suggestion for the best way to seal up the air-leaks around the damper I would appreciate it. I would like to be able to get something in there tonight.
Would a little quick-set be the best choice? I have used it to set posts, but never to patch a hole. I don't know if it will hold, or just fall out of the spaces and crumble.
Any advice is always appreciated.
ar
It's worse than that!
You see you need oxygen to have a fire and that comes from the house.. the heated air inside the house. it goes into the fireplace and is burned and then goes roaring up the chimney. Mother nature hates a vacumm so she lets in some nice cold outside air thru whatever way she can get it in the house. Now your furnace has to kick on to warm up the air that was sucked in from outside to replace the air that went up the chimney..
Directly in front of the fire you feel warm but if you have an accurite quick reacting thermometer you will see that the rest of the house got colder, actaully if you were extremely sensitive you'd notice that your back is colder as the fire was burning because all of the air rushing past it to get to the fire..
So yes you get cold air from a damper that's open (think of it as an open window the size of the chimney) but even when you ar burning wood the furnace needs to run to generate heat to replace all of the warm air that went rushing up the chimney.
So true. The air for combustion has to come from somewhere. Mine comes from the bathroom vent. Start a fire and cold air just flows through the vent.
not just air for combustion, but there is a convection flow up the chimney as the heat rises. This convection moves hundreds of cubic feet of warm air, warmed by your furnance, up the chimney each minute. Now if you have a vent in the firebox to allow out side air directly into the firebox, the flow of convection air can become mostly cold outside air and not warmed air from the house, but even here it ani't perfect.
I do apreciate the input, but the fireplace is there, and not going anywhere. I might be able to get a chimney top damper installed, but not today as there is 6" of snow and ice on my roof.
If anyone has a suggestion for the best method of sealing cracks between the masonry and the metal damper, I would love to hear it. If there are any injectable products that are fire-safe, or some type of patching cement that might hold better than plain old quick-set, please let me know.
Thanks again,
a very cold ar in IL
Maybe that red fire stop caulk would seal the cracks and be heat resistant enough for your purposes.
Spheramid Enterprises Architectural Woodworks
I have irriatable Vowel syndrome.
I found this :
http://www.nsipolaris.com/pdf/firestop.pdf
they have mortars, puttys and caulks that are all fire resistant. I will try and do some more research into whether they would be suitable, but thank you for your suggestion.
If anyone has experience using this type of product in an application similar to mine, please let me know
ar
I think the caulk would be easiest to apply, or the mortar if you just get a grout bag and nozzle.
Spheramid Enterprises Architectural Woodworks
I have irriatable Vowel syndrome.
There are special mortars for the fire box application. If there is a masonry supply place near you give them a visit and explain your desire to repair the mortar at the damper. They should be able to set you up with what you need no problem.
Edited 12/8/2006 9:41 pm ET by dovetail97128
Supposed to warm up a bit next week. 40's last I heard.
jt8
"When one door closes another door opens; but we so often look so long and so regretfully upon the closed door, that we do not see the ones which open for us." -- Alexander Graham Bell
"I have twelve (12) of the spring-loaded chimney top dampers, with the cables running down into the firebox."Boy that firebox must be very crowded with the controls for for 12 damper.Are the dampers mount one on top of each other. Or are they side by side. If they are side by side them you must have a Sanat Sized chimney.---There is one in every crowd and I have been elected to be the one. Maybe I should make that my tagline.
Well, you just open the amount sized to your fire. "Honey, that's a 6-damper fire - why in the *&% do you only have 4 opened?
Forrest - one as well
You're already received some excellent responses which should lead to a solution for you.
But I'll go ahead and toss out my 2 cents while I'm here. That would be to put an efficient insert into the fireplace. In that manner you could turn the fireplace into a heat source rather than a heat drain.
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jt8
"When one door closes another door opens; but we so often look so long and so regretfully upon the closed door, that we do not see the ones which open for us." -- Alexander Graham Bell
Ar & ALL,
Here is a related tangent to this thread (and a correction of some misleading info posted):
On fireplace efficiency, Most fireplaces constructed in the last century or so are 5-10% efficient when operating (90-95% of the heat produced lost up the chimney). The negative efficiencies result from heat lost from the house up the chimney the rest of the time (since most fireplaces only have fires burning in them a few hours or days each year).
Count Rumford fireplaces, on the otherhand are 30-40% efficient due to their tall, wide, and shallow design with splayed out sides. This brilliant design provides far greater surface for radiating heat. Rumford also designed the throat of the firebox/chimney junction so that it functions like a Venturi on a carburetor and in the case of these fireplaces the exhaust gases generate a secondary burn and boost heat generated in this way too...a late 1700's version of a turbocharger, so to speak.
This article on the subject was written for JLC:
http://www.rumford.com/articleRumford.html
Of course, the fluetop damper would boost the total efficiency of any fireplace by minimizing losses when they are not in use.
If you install a flue top damper you shouldn't need to repair the existing one , at least if my understanding that this opening has been converted to a gas unit is correct.
If you do not have outside combustion air ducted to within 12" of the fireplace find a way to do so , this is the best way to maximize whatever heat you are getting out of the unit. The outside combustion air will minimize any drafting of air around windows, doors , penetrations etc.
You've got two things working against you. ONE- you're attempting to heat the house with a fireplace TWO- you switched to gas from wood.
The damper problem you have is not unusual and even when you fix it, it's still going to loose more heat then you can generate using the fireplace. Think of a fireplace as a hole in the wall that is open 12 to 14 hours a day letting the heat out of the house.
To solve some of your problems, take out the gas logs etc. and put in a wood burning, or pellet, stove insert into the firebox. The stove has it's own damper in it that can be closed off and when it's not in use you can practically eliminate heat loss up the chimney. The wood stove or pellet stove is more efficient and completely seals the whole face of the fire box and you don't have to do anything with the existing damper except be sure it's completely open before you install the stove insert.
again, I would really like to thank all who have responded, or will.
I think either I was unclear, or someone has led this thread a little astray. Perhaps it's because I posted in this forum instead of the general discussion.
So let me clarify. I do NOT intend to use this fireplace for heating. It is purely decorative. I do like to make fires in it, so I do not want to entirely close off the flue.
It is in the basement den in my 75 year old house, and the previous owner converted it to gas log during a major renovation of the house.
My real concern is how to minimize heat loss when it is not in use. This is 99% of the time. The are clear openings between the mortar and metal, and I am interested in sealing these with something that will go in pretty easily, stay in place when set, and most importantly, be fireproof. I am hoping to find some miracle fireproof expanding foam that will just spray right in and help.
I will be pursuing the chimney top dampers, but so far I have read that they are NOT recommended for gas fireplaces, but I am sure they are commonly used that way. My guess is that is because on a wood burning fireplace, If the damper failed to open, you would know because smoke would back up, but with a gas fireplace, if it failed to open, you would not necessarily know (you can't see it) and the only thing backing up would be carbon monoxide.
I do have a detector installed in the lower level, as well as one outside our bedrooms on the second floor.
Again, I do not want to seem unappreciative of the great feedback here. I really enjoy this site, and love the valuable information that is passed from hand to hand.
thanks,
A not so cold (it was up to low 30's today) ar in IL
Edited 12/10/2006 9:53 am ET by ar7499b
Home improvement centers sell a fireplace mortar in a caulking tube. I've used it to seal up cracks in my fireplace. I've had the same problem you've had with your damper. Even after I got the masonry repaired the damper still leaked. Most dampers aren't built to seal well. I temporarily sealed mine of one winter by cutting some structural insulating foam to size and stuff it up into the throat of the fireplace. Given your situation this might be a good temporary solution for you.
I agree with the recommendation to install a flue top damper like the ones covered in a recent issue of FHB. I doubt you ever get a throat damper to seal nearly as well.
I also agree with most of what's been said regarding fireplaces as energy wasters though I'd ours did heat our house well I think only because it had an outside air source damper located near the front of the firepit. However, we've since installed a freestanding direct vent gas stove in the fireplace. Exhaust and air supply hoses run to the top of the flue to a weatherproof cap there. Works great!
thanks for the tip. I bought a tube today and wil try it out.
ar
I understand it well. I just think a very poor job was done installing that sealing plate. The ones I installed never back drafted as yours does.The correct procedure for making such a plate is to make a template to fit the damper openning, then use it to fashion a sealing plate. I did this by making two plates of 12 ga steel with a 1" FG insulation made for hot packs like this. The two plates were separated by the FG and then wrapped with a 1" C-channel, all held together with pop rivets. This was then fitted up into place - a very dirty job - and held there by angle iron tabs fastenbed to the throat sides. The new smaller dampers are made a part of this unit. a 2000°F silicone or flue cement in a tube caulked the small gaps left. Your description of several inches left open for cold air to backdraft is what suggests to me that the installers had no knowledge of the right procedure. Keep the CO detectors close.Since I am not there, I have a hard time suggesting a way to repair without a complete rebuilt of this instal. I might think it would be possibnle to add 12GA steel to extend with rivets or SM screws to hold it in place and furnace cement or refractory cement to fill gaps. I'm only imagining the exact details from here...
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