Wood Fireplace Ventilation

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Gilly826

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Hey all,

Hoping to get some well needed knowledge on why my fireplace is not operating properly. Hope this is the right section for this type of post.

I moved into my new home (50's era) in January and decided I wanted to convert our (illegally installed) propane fireplace (originally wood), back to wood burning. Everything was still in its place, so all I had to do was remove the gas log set and gas line. With the flume open I can clearly see the outside, its a single story house so the chimney is not very tall. There doesnt appear to be any obstructions.

Since we have hit some cooler temps as of recent, I've had the chance to test out the fireplace a few times. Overall, it works well.. But our house clearly smells of smoke, and at times Ive seen some smoke being "pushed" into the house. Last night the fire was dying out and it seemed as though without the heat or the fire pushing the air up, its easiest escape was to fill the house with smoke. Im wondering if its simply becsuse of the design of the fireplace it self, the opening of the flume seems rather small to me. Maybe the top of the chimney needs a cap on it? Will post pics soon, thanks!
 

bud16415

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For a fireplace to work properly you need to establish a draft in the chimney the flue size and the chimney height both factor into proper draft.


I used to burn some paper or cardboard first to heat the chimney and get the draft started and get the smoke going in the right direction.



The trouble with these old fireplaces is they use the heated air in the house to make combustion and then send it up the chimney. They many times waste more heat from the house than they make.


When the fire dies down the chimney cools down and you don’t have draft, and you have to leave the flue open for hours getting rid of the last of the smoke and still sucking warm air from the house. Any draft that goes up the chimney has to be made up by leaking outside air into the house. If your house is sealed tight it is hard to get a working draft without leaving a window cracked. Glass doors help with closing the fireplace off as the fire dies.


The best method is to have a sealed unit that burns by bringing in cold outside air for combustion.
 

Gilly826

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For a fireplace to work properly you need to establish a draft in the chimney the flue size and the chimney height both factor into proper draft.


I used to burn some paper or cardboard first to heat the chimney and get the draft started and get the smoke going in the right direction.



The trouble with these old fireplaces is they use the heated air in the house to make combustion and then send it up the chimney. They many times waste more heat from the house than they make.


When the fire dies down the chimney cools down and you don’t have draft, and you have to leave the flue open for hours getting rid of the last of the smoke and still sucking warm air from the house. Any draft that goes up the chimney has to be made up by leaking outside air into the house. If your house is sealed tight it is hard to get a working draft without leaving a window cracked. Glass doors help with closing the fireplace off as the fire dies.


The best method is to have a sealed unit that burns by bringing in cold outside air for combustion.
Sounds exactly like the problem I am having. For me, the fireplace is mostly aesthetic.. But the smoke in the house is not what I'm looking for. When I bought the house we ripped down the walls and insulated with mineral wool, but we still have yet to insulate the attic and I feel there is enough draft in the house to allow the chimney to ventilate.. Which I guess is why I was leaning towards the flue being too small. Will post pics soon

My fireplace does have an ash catcher/door (cant remember what its called), is there a way to turn that into a proper draft for the fireplace? Thanks!
 

bud16415

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If you want to burn wood and have some sort of efficiency but still be able to enjoy the look and feel of the fire and maintain a degree of safety in your home, I would recommend a good quality fireplace insert.


I’m not up on what is the current best products, but I do know there is little you can do to one of these 1950’s fireplaces to make them actually produce heat. They are great for a couple nights a year to get that fireplace feeling but that’s about it.


You also need to make sure your chimney is clean and there are no cracks in the fire liner. Something you never want to experience is a chimney fire. I had one once 40 years ago and I will never forget it. It sounded like a jet engine and I ran outside to see flames shooting 20 foot out of the chimney and raining down chunks of fire.
 

slownsteady

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Your chimney may not be tall enough. It has to be a certain height taller the the peak of your roof. Best bet is to get a professional sweep to take a look at the whole setup.
 

oldognewtrick

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And you probably know why the previous owner installed the gas logs. I agree with S-N-S, get a chimney company to come look at it. I have a friend who's a brick mason who has rebuilt the smoke shelf in several fireplaces and made them draft better.
 

Gilly826

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Thank you all for the replies. I will be giving a chimney company a call and hopefully I can get an exact answer. Hopefully its not too expensive, I'm about tapped out for the year!
 

rbm328

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i had a wood burner 15 years ago. when it was roaring, it heated the room (living). what i also remember is that the draft created to remove the smoke, sucked the heat out of the rest of the house. in the house we currently live in, we have a ventless natural gas log set and it works great! along with talking to chimney company, you can talk with your gas company. if you decide to go with gas, see if there is natural gas in your area. natural gas is cheaper, never needs to get refilled and burns cleaner. propane has moisture in it; thats why gas grills rust out in the burners so quickly.
 

Gilly826

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i had a wood burner 15 years ago. when it was roaring, it heated the room (living). what i also remember is that the draft created to remove the smoke, sucked the heat out of the rest of the house. in the house we currently live in, we have a ventless natural gas log set and it works great! along with talking to chimney company, you can talk with your gas company. if you decide to go with gas, see if there is natural gas in your area. natural gas is cheaper, never needs to get refilled and burns cleaner. propane has moisture in it; thats why gas grills rust out in the burners so quickly.
For me, the wood fireplace is more for aesthetics than it is heat..As are a lot of gas fireplaces I see being used. (I work for a propane company, and deliver gas) You would be amazed at the amount of people burning gas just to watch the flames dance. Guess thats what you do when you have too much money. :) I know wood fireplaces are/can be a waste, but its what I prefer. Even though I can get gas for cheap, wood is free!

Side note: Im not sure what you say about natural burning cleaner is true. Most propane appliances burn at a 99% efficiency. Propane does have moisture (as does natural gas, not sure how much though) and thats why our tanks are filled with methanol. :)
 
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