Still getting cold air

[qwertyjjj]

I made a block off insulation and installed in the summer (no plate, just the insulation): https://www.hearth.com/talk/threads/cant-figure-out-how-to-remove-baffles.162735/#post-2186713

This has improved the situation a lot but I'm still getting cold air coming through. I think it's coming directly through the fireplace as when I close the choke, it reduces but it never reduces 100%
It's and Enviro Venice insert.
Could it really be coming through the insert and is there anyway to stop it? Seems bad design.

 

[redktmrider]

This has improved the situation a lot but I'm still getting cold air coming through

Where is the cold air coming through? Is it an exterior masonry chimney?
The insulation will slow down the air but a solid block off plate that is sealed to the damper area is much better.

 

[qwertyjjj]

It's an insert in an exterior chimney but the air feels like it's coming from the area just below the fireplace door (not the actual door or seal). This is also the same area that I get smoke coming out from if I light the fire without cancelling the downdraft by opening a door. It's like a lip under the door just here

 

[jatoxico]

If you have down draft issues then you'll prob get air coming out of the stove when not in use through the non-controlled air passages and the little bit that gets around the primary air which, as you prob know, can't be fully shut.

Happens to me and it is what it is. I get very little and it's actually not noticeable unless I put my hand right to the intake or in this case out-take.

Much better than when it was an open fireplace. I did add a full metal plate and fully insulated the smoke shelf and firebox.

 

[redktmrider]

On my T5 insert, that's where the primary air intake is. I looked at the manual for the Venice, could not tell if for sure if that's were your air intake is.
I agree with jatoxico, the down draft is probably the culprit.

 

[Hogwildz]

Insulation does not stop airflow. That is the first thing to fix with a block off plate.
The cold air at the front lower sounds like cooler air drafting to the stove as warmer air moves away from the stove.
There ins't an ash clean out for the original firebox that wan't sealed is there?

 

[qwertyjjj]

Insulation does not stop airflow. That is the first thing to fix with a block off plate.
The cold air at the front lower sounds like cooler air drafting to the stove as warmer air moves away from the stove.
There ins't an ash clean out for the original firebox that wan't sealed is there?

No ash cleanout. The block off plate would only stop the air from the brick chimney. How do I stop the air coming down the insert? The room feels like it has a cold draft at foot level in front of the fireplace.

 

[jatoxico]

How do I stop the air coming down the insert?

You don't. I guess if you wanted to you could remove the baffle and put some insulation in the vent. Fire up, problem solved.

 

[redktmrider]

How do I stop the air coming down the insert?

You could block the liner with something like a kids inflatable ball, but make sure to remove it before starting a fire. You will have to remove the baffles to do so, so just leave them out when the ball is in place.
You need to improve your draft, if its cold out and you have a downdraft situation, the chimney system is marginal at best. Is the liner insulated?

 

[qwertyjjj]

No, liner is not insulated. Chimney is outside the house so can't really be heated... not even sure insulation would help?
It's covered with a metal plate at the top where the liner goes out through the chimney. Draft is always bad due to extreme cold temperatures. Old fireplaces used to have dampers, is there anything similar for an insert?
I can't put anything at the top due to ice and snow possibly blocking it.

 

[redktmrider]

Your draft should increase as the outside temp falls, not decrease. Check this out for a little background info.
http://woodheat.org/all-about-chimneys.html

How tall is your chimney?

 

[redktmrider]

I think you are going to have to block the liner or the air intake on your stove when you are not burning, it really sounds like your chimney experiencing down drafting.
Maybe the chimney sweeps on here know some other solution.

 

[moresnow]

Any chance there is a OAK on this setup that could be supplying the un-needed cold air you are feeling? A thought.

 

[qwertyjjj]

Your draft should increase as the outside temp falls, not decrease. Check this out for a little background info.
http://woodheat.org/all-about-chimneys.html

How tall is your chimney?

It does increase as it gets colder.
Chimney is about 40ft tall.

 

[qwertyjjj]

Any chance there is a OAK on this setup that could be supplying the un-needed cold air you are feeling? A thought.

Couldn't see anything when we took the insert off to do the n insulation. Where would the oak be?

 

[Hogwildz]

No ash cleanout. The block off plate would only stop the air from the brick chimney. How do I stop the air coming down the insert? The room feels like it has a cold draft at foot level in front of the fireplace.

A lot of cold air will drop down from the masonry chimney if no block off plate is installed. That could very well be part of your problem.
If you're talking about reverse draft with insert not running, most of us run 24/7 and do not have that problem. The only thing you can do is block off the stove outlet when not in use, but leave a note so you remember to pull the rag or whatever you're blocking the outlet with, prior to firing up the stove the next time.

 

[redktmrider]

It would either connect to the air inlet on your insert or dump outside air behind the surround which then has to be sealed against the face of the fireplace opening.

 

[venator260]

On my fp25, I get some cold air there. I've not had a ravers draft problem, even on cold starts on cold days, so I've attributed it to a bit of cold air from the oak getting through. The air control also changes the amount coming through.

Generally though, as others have said, if it's cold enough to cause a problem, I'm going to be lighting a fire soon anyway.

 

[qwertyjjj]

A lot of cold air will drop down from the masonry chimney if no block off plate is installed. That could very well be part of your problem.
If you're talking about reverse draft with insert not running, most of us run 24/7 and do not have that problem. The only thing you can do is block off the stove outlet when not in use, but leave a note so you remember to pull the rag or whatever you're blocking the outlet with, prior to firing up the stove the next time.

The air used to come from behind the fireplace. That has stopped since we put the insulation in. Now it's just from the front of the air inlet.
This is only when the fireplace is off.

 

[Hogwildz]

The air used to come from behind the fireplace. That has stopped since we put the insulation in. Now it's just from the front of the air inlet.
This is only when the fireplace is off.

You have reverse draft then. Coming down the liner, into & out of the stove.

 

[semipro]

There are chimney caps that integrate a cable operated damper.

 

[moresnow]

There are chimney caps that integrate a cable operated damper.

Hmmm. Bet I'd have that messed up quickly!

 

[qwertyjjj]

There are chimney caps that integrate a cable operated damper.
View attachment 218879

Won't this get blocked with ice? Snow on sides melts in the sun then refreezes blocking the damper

 

[semipro]

Won't this get blocked with ice? Snow on sides melts in the sun then refreezes blocking the damper

I'm not sure. It looks to me like ice forming on the outside would not interfere with the damper but I don't know first-hand.

Edit: There are larger caps for masonry chimneys that would certainly prevent ice from interfering with the damper.

 

[qwertyjjj]

I'm not sure. It looks to me like ice forming on the outside would not interfere with the damper but I don't know first-hand.

Edit: There are larger caps for masonry chimneys that would certainly prevent ice from interfering with the damper.

Does this cap cover the insert as well? I would need a round cap for the insert. The brick chimney is already covered with a steel cover though ...
If not, how do I fit/secure the round insert to the square damper?