Cold draft when running stove

[bryan]

Wasn't certain where to place this so here goes:

Burned for the first season last year using a insert in a preexisting fireplace in the basement. Heat does travel upstairs without an issue, not that I'm trying to heat solely with wood. The real issue is the cold draft that comes into the room. I don't know if it is make up air due to air going up the stack or simply air replacing the hot air leaving the room (convection), but as room is laid out the seating is by the door into the room so when the stove is going you can feel a cold draft going past you. Likewise I can measure the floor temperature using an IR gun and the floor gets ~5 degrees colder in the doorway after oven is going (I only burn in the evenings).

I'm spending some time before it gets cold trying seal up the basement better (sill plates, etc) thinking that make up air is getting pulled straight from the outside. Does anyone else have this issue? Am I crazy thinking its make up air to replace the air going up the stack?

 

[Jags]

Moved this over to the main wood stove forum.

Sounds to me like you are feeling the effects of "make up" air. Get that draft sealed up.

 

[mellow]

Another option would be an OAK (Outside Air Kit) but upon a cursory look at your CW2500 that is not an available option.

Get to work on sealing up those holes, you will notice a huge difference if you do.

 

[KaptJaq]

When I burn only the downstairs stove I also get a cold draft at the bottom of the steps leading into the stove room. In my case it is the cool air from upstairs tumbling down the stairs to replace the hot air that is going up via a vent at the other end of the room.

Once the house is warm do you feel any difference in the draft?

KaptJaq

 

[Backwoods Savage]

This is perhaps the #1 reason people put in an OAK. That way the stove does not draw air from inside the house and it cuts down on those drafts.

 

[bryan]

I had looked late last year and saw an OAK was not available with the CW2500. Even if there was one available it would have been painful in a basement corner install. I could probably jury rig something using the sliding glass door right next to it, but I'll pass for now. I'm positive the Mrs wouldn't approve of that. That and OAK's seem to have a quite divided crowd here on their usefulness and whether they cause other problems.

I'm kinda torn as to whether to seal the basement up. In ways I'd rather be burning the cold air than to have warmed air from upstairs being burned but probably best that I hinder the over all chimney effect of warm air leaving the top floor as cold air comes in the bottom.

As for if it gets better once the stove is warmed up I'm not quite certain. I do know it was worse the colder it was outside which made me feel that it couldn't have been air from upstairs. Just sad that the room can be in the mid 70's but its uncomfortable to have you feet on the floor due to the draft.

 

[TradEddie]

Sealing the basement area could mean that make up air will now come from upstairs exclusively, causing an even bigger draft. I sometimes crack the sliding door in the stove room, and it reduces the cold draft downstairs, and surprisingly, improves the heat flow to the upstairs. Many here say they crack a nearby window. OTOH, I have to sing the praises of rim-joist sealing on my heating bill, and even more on my cooling and dehumification this summer, so I recommend you do that anyway. I think you are just feeling the retuning air that is replacing the warm air going upstairs.

Also, how much air are you giving that insert? A properly cruising stove should draw very little air, but if you are trying to burn unseasoned wood, or are burning too hot, that will require much more makeup air.

TE

 

[Hogwildz]

Another possible cause is as the hot/warm air leaves the room, it will also draw cooler air from the rest of the home. Same idea as using a fan to blow cooler air towards the insert/stove to create circulation or a convection loop.
I have this same thing happen at floor level to the insert.

 

[Soundchasm]

I don't know if this avenue of investigation applies to you, but here's another thought. I have a draft of air running across the floor when I use the upstairs stove (a new model), and it is unfortunate. I can't positively track what's happening for certain. I've puzzled on it quite a bit, and that makes any small irritation worse to focus on it. I have a positive draft to the old smoke monster downstairs, and I do crack a vent to feed that thing.

Here's the point. I suspect what I'm noticing is the air being pulled into the fans of both units. Don't know any CFMs off the top of my head, but the air has got to be pulled in to be heated and sent back out. Of course the fans are going to draw the cold, heavy air on the floor. I'll be doing much more research this winter!

The other "Thank you, Mr Obvious" moment I had was checking the smoke (or no smoke) from the chimneys. I have to figure that everything coming out of the chimney had to be inside my house a few seconds prior. Nature abhors a vacuum and all that is going to be replaced.

 

[Huntindog1]

Is your insert a direct hook up to a chimney liner? If not is your surround sealed good as it could be sucking air around your surround up the chimney.

If its a tight system with a direct hook up to a chimney liner. I dont imagine the air used by the stove is the issue as these stoves use so little air thats one reason they are much more efficient. With the insulated fireboxes raising the heat and maintaining the heat inside the fire box this lets the stove burn using much less air. Reducing the input air settings to much lower levels reduces the air velocities thru the stove which means the heat in the stove has much more residual time in the stove. Simply put, your heat isnt quickly whisked up the flue before it has a chance to radiate out into your room.

I imagine since your getting heat up into the upstairs what your feeling is conventions flows. As the heat rises its pulling air from some other part of your basement and maybe the air is coming from the outside from some leaky part of your basement.

One way to correct this is like you said seal up the basement better then you could put you a vent from up stairs to the basement down at the other end of the house so your create a loop which relieves the suction of the heat rising from pulling in cold air from the outside.

Lastly it could just be that the other end of the basement is cold so the air movement is cold.

Oh one more thing, my masonry flue does not have a stainless steel liner so its not a direct hookup the clean out door at the bottom of the flue would would suck alot of air, so I sealed it.

 

[Backwoods Savage]

Wasn't certain where to place this so here goes:

Burned for the first season last year using a insert in a preexisting fireplace in the basement. Heat does travel upstairs without an issue, not that I'm trying to heat solely with wood. The real issue is the cold draft that comes into the room. I don't know if it is make up air due to air going up the stack or simply air replacing the hot air leaving the room (convection), but as room is laid out the seating is by the door into the room so when the stove is going you can feel a cold draft going past you. Likewise I can measure the floor temperature using an IR gun and the floor gets ~5 degrees colder in the doorway after oven is going (I only burn in the evenings).

I'm spending some time before it gets cold trying seal up the basement better (sill plates, etc) thinking that make up air is getting pulled straight from the outside. Does anyone else have this issue? Am I crazy thinking its make up air to replace the air going up the stack?

Bryan, I did not see if anyone had asked if your basement walls are insulated. If not, that would certainly add to the cold draft and also most of the heat would be soaked up in the walls.

 

[BrotherBart]

It happened with our old insert in the family room and also happens with the free stander in the fireplace now. In fact before we rearranged the furniture the air headed to the stove would be pulled up the back of the couch and across your neck if you were sitting on the couch. Mostly it is cold floor level air the stove and the blower are pulling in.

 

[bryan]

The basement is half finished and those walls are R10. The half that is not is not insulated at all, but there are doors that close that portion off. I hope to eventually insulate the whole thing, but probably won't happen this winter. I know those walls are 55 F in the winter. Putting up furring strips to mount insulation is going to require a good bit of rearranging of wiring/plumbing. Thanks for all the comments as its good to know I'm not having an unusual problem.

The insert doesn't have a surround (don't like the look). The cap/liner is sealed at the top, but I need to get to work on making a block off plate anyhow. Currently the gap is currently filled with roxul

 

[Sprinter]

I'm well in the OAK camp, but modern stoves only pull from 10 - 25 cfm of combustion air (from what I've read). That doesn't seem like enough to create an objectionable draft in the house. I'd think such drafts would be due to convection circulation.