Firebox modification to put a new mantel on

[Bruhan55]

Hi, my first post here...

I bought a project house, and am at the point where I'm going to put a new mantel in. The existing firebox has two "vents" terminating above the box, supposedly meant to push heat into the room and if it actually did that, I'd be happy to include some form of venting space included in the mantel but two winters of burning wood in this thing have shown me such is not the case and I want to simply close it in by either filling it with whatever (fireproof of course) or simply closing off the two front holes.

I was a young carpenter's apprentice in the early '70's when this house was built and we used to put these things in most houses but I seem to remember most had a fan system to push the air out. This one doesn't...

I don't see a problem closing them in but I'd prefer to hear from someone who's perhaps been in the same spot as me, pros and cons, yays or nays kinda thing.

thanks!

 

[begreen]

Looks like a heatform style fireplace. If the goal is to heat with the fireplace, install an insert in it.

 

[Bruhan55]

Looks like a heatform style fireplace. If the goal is to heat with the fireplace, install an insert in it.

I use it to burn wood occasionally but I spent the big bucks on a high efficiency furnace and it heats pretty cheap. All I'm planning to do is the new mantel surround and I don't want to leave holes for those "vents" in the front. Still plan on burning a little next winter...
Thanks for replying tho, much appreciated!

 

[bholler]

I use it to burn wood occasionally but I spent the big bucks on a high efficiency furnace and it heats pretty cheap. All I'm planning to do is the new mantel surround and I don't want to leave holes for those "vents" in the front. Still plan on burning a little next winter...
Thanks for replying tho, much appreciated!

You need to let that box ventilate the heat has to go somewhere and you don't want it trapped in your wall

 

[Bruhan55]

You need to let that box ventilate the heat has to go somewhere and you don't want it trapped in your wall

Thanks for the reply!
Do you really think the box needs those two pipes to ventilate? They terminate on the floor of the masonry box and tho I can't confirm, I'm guessing they have a metal cap welded on the bottom to prevent bugs or? in the off-season. My thoughts are that they aren't an intake to provide cool air, they're an exhaust to provide more heat into the room...(which they don't do as previously mentioned). Other than the metal firebox, the fireplace is 100% masonry and as such is built to take any heat thrown at it. So much of that heat goes up the chimney unfortunately but even the brick on the back of the fireplace doesn't get even warm after a few hours of heavy burning.
Please don't take this as an argument, I really appreciate your opinion, but there's no walls to trap the heat in a masonry chimney. 🙏🏼

 

[bholler]

Thanks for the reply!
Do you really think the box needs those two pipes to ventilate? They terminate on the floor of the masonry box and tho I can't confirm, I'm guessing they have a metal cap welded on the bottom to prevent bugs or? in the off-season. My thoughts are that they aren't an intake to provide cool air, they're an exhaust to provide more heat into the room...(which they don't do as previously mentioned). Other than the metal firebox, the fireplace is 100% masonry and as such is built to take any heat thrown at it. So much of that heat goes up the chimney unfortunately but even the brick on the back of the fireplace doesn't get even warm after a few hours of heavy burning.
Please don't take this as an argument, I really appreciate your opinion, but there's no walls to trap the heat in a masonry chimney. 🙏🏼

But if you seal off the face there the heat will be trapped and it will find it's way out. You don't have much masonry above that box at all where your mantle will sit. I have seen several where the trapped heat was causing strange smells

 

[Bruhan55]

Noted. Thanks kindly.