outside combustion air

[bigdaddy1010]

I am in need of some advise.

I own a 50 year old block home with (2) fireplaces in the Philadelphia area that is very drafty.

I Love having fires, but have noticed significant heat loss with the open flame fires. I want to add a vent to the outside to introduce outside combustion air, but need some advise on how to go about it, and if there are kits to do so. I don't have access to the underneath of either one (i.e. ash dump pit) so I will need to break through the back of the fireplace. Are there kits or resources available to facilitate this modification as I'm concerned with embers possibly going out the vent.

Are there spark arresting vents available??

Please help

Bigdaddy1010

 

[carpniels]

Hi BD,

I don't get it. What are you trying to achieve? You have plenty of combustion air because your house is drafty. So what is the big idea behind this?

Carpniels

 

[bigdaddy1010]

Sorry,
To be more specific I am trying to minimize the "pull" of the air inside my house from going up the chimney. My thought was that considering the path of least resistance that a vent to the outside would provide the fire with the air that it needs without it drawing as much heated air from the house.

Bigdaddy1010

 

[coldinnj]

Good idea Big Daddy.
Keep in mind this. If you were to come up with a vent to the outside:
1) proporcionate it or have some form of control on it to regulate the amount of air it is able to bring in to match what is needed for the fire.
2) Be able to completely chut it off when not using the fire.
3) have it very wel insolated so you do not achieve more heat loss through it.
4) Have it isolated enough from the POC from the fireplace so as not to bring "bad" air back in.
5) Try to have it bring the air in to the front of the fire place, not the back.
6) Try not to go through the brick work. Wood is easier to repair if the idea doesn't last or you want to sell and the new occupants don't like it.

 

[MountainStoveGuy]

If its not a sealed combution device, which a fireplace isnt, then its going to pull air from the path of least resistance, which in this case is the room that its in. It will be very hard to make the fireplace pull from a 4" vent whent here is a 36 x 24 opening right in front... If you had tight doors it might work.

 

[bigdaddy1010]

Thanks, If I do decide to do this my intent was to use glass doors

 

[MountainStoveGuy]

most doors arent tight enough to force combustion air, there leaky enough that the cumalitive cracks still offer air easiier then a outside air kit. You will want to buy very good doors, which in some cases will cost almost as much as a efficient insert. I would look at a insert to solve you problems with air loss in the house.

 

[elkimmeg]

For years code has required outside air kits for fireplaces especially with all the new energy codes and homes being so tight Since Most states have adopted the international codes outside air is required for new homes. The ones that used the ash dump w are convoluted and tend to jam up However there is another type that goes threw the rear brick wall that has a slide damper plate in front of it where it can be fully open of any position inbetween. As for you drafty home like the other posters told you the fireplace is still taking a huge vollume of air with it up the chimney along with most of the heat Burning a fire place draws more heat out of your home than it produces no mater the adition of an outside air kit
here is a link to the back wall type open up the PDF for a picture
http://www.concretebuildingsupply.com/index.php?page_id=39

 

[MountainStoveGuy]

my point is that the outside air is useless unless the fireplace draws from it. If the front is open, or if there is leaky doors, then its not going to pull from the OAK.
Nice link elk.