Home Forums Hunting & Shooting Hunter's Campfire Wood Stove/AC/Smoke Smell....??????

Older IE 86 Earth Stove. I have no instructions for it, its in grandparents house that we moved into, in October. Brick well sealed and built house from 86. Tight house.

Just now turned on the AC and it is pulling smoke smell from somewhere....

I pulled the pipes, they go into a brick chimney and a round 8 inch single wall through a square hole in the bricks but the edges are stuffed full of insulation... which I added to the other day. Thought that should solve it.
Emptied the stove of 95% of the ashes, IE did not vacuum them out....

Turned the AC on again last night as it was around 82 in here and this morning smoke smell again. Have the same thing when we got home from work.

There is a vent for lack of terms on the back.... it contains the damper, and its open when we burn. I have that flap shut, and the damper off.

Where is the smoke smell pulling from? Should I open the damper possibly? That would seem backwards to me though...

When was the last time the stack was cleaned for the Earth Stove?

Rost,

How close is the a/c intake vent to the fireplace?

Do you have the heating vents on the fireplace closed?

JM

Does the house have a furnace as well?

I used to do a little work on wood stoves and chimneys. Got a call from a guy with the same problem your describing. When the air intake for his furnace came on it was more powerful than the chimneys draft. So it would pull smoke down the chimney and out from behind the stove. In his case he could only run one or the other. It took me awhile to figure it out becuase the fan was pretty quiet and the problem seemed to come and go.

I did seal up the top plate for his chimney cap, witch seemed to help, and insulate around the stove which nearly fixed the problem. But his intake was in the same room with the stove and would still over power the draft a little.

Stack was cleaned of creosote in October before we burned. Also chimney brushed the red tile stack from the roof. We burn only oak. I pulled the pipe last weekend and creosote was there, but a very fine layer. Barely enough to try to scrape off with a scraper.

John... its a wood stove, not a fireplace if that matters. Return air duct is about 20 feet away around a short corner 3 foot around the corner.

I don't know the term heating vents... the thing that gives it extra air from inside the house is closed as best I can. And the damper thats in the stove is in the closed or low heat position.

You waited a while to turn on the A/C...

Yeah... trying to conserve.....

rost,

I work in the plumbing and HVAC biz. Can you clear up a couple questions for me?

The smoke smell; you are only getting this when the A/C is running, meaning the blower on your furnace is moving air. Correct?

Is the smoke from a recent fire in the wood stove, such as an overnight fire to take the chill off, or is it old stale smoke smell?

Is your furnace a high efficiency, 2 pipe vent/exhaust system? These are usually vented with white PVC pipe. If so, where is it vented?

I might be able to help you if you can answer these questions for me.

My cold air return is in the same room as the wood stove. It is not unusual for a smoke smell to be sucked into the room from the stove if there has been a recent fire. If it is cold out, or blazing this does not happen. That is, it only happens when there is smoke to suck out, and the return draft is greater than the updraft.

How cold is the supply air from the ac?

If the house is 82, the supply air should be about 62, when you first start the ac, and then cool down as the house cools.

If you haven't had a fire in the stove, you may have the heat strip energized along with cooling.

1. Smoke smell ONLY while AC is running. IE only when blower fan is moving air.
2. No recent fires.... actually can't recall the last one... might have been almost a month ago possibly? at least 2-3 weeks.
3. Furnace I think... I"d have to look as we didn't have it put in but its Carrier IIRC and a 2 speed with heat pump around 18-20 seer IIRC... I do NOT recall seeing a PVC vent but can go look tonight. The vent, IIRC of course goes through the roof.... where the unit sits on top of the return air but I may not remember right either...

I don't have a digital thermo... but can stick a regular one in the vent... of course today we go away from AC weather as it drops to the upper 30s tonight they claim....
Heat strip is not energized in the heat pump situation, we never set the unit on auto... and never run the heat period. Its either on cool only or off.

It is possible that the return air side of your system(some call it a cold air return) is picking up the smoke smell. The other possibility I can think of right now is that there may be a make-up/fresh air intake tied to your return air duct work. It's possible that this is located in an area where it could suck in smokey smelling air when your furnace blower is running.

Just a WAG, but is there any chance that someone may be coincidentally burning something outside at the same time you have the AC running? A fresh air intake in your return air duct would pick that up an bring it inside.

Another odd question: is there a combustion/fresh air supply to the wood stove?

I realize I'm asking a lot of seemingly unrelated and odd questions, but without seeing the installation it's hard to understand how things are setup.

I'd really like to help if I can. I like the challenge of trouble shooting and enjoy helping people solve problems with their homes.

Offer all the info you want. I'll be happy fo offer any help I can.

The house has the return air about 20 feet or so from the wood stove. The return air is the large duct that has the air filter in front of it, and a metal grate... goes up to the unit in the attic, IE Furnace. So yes it probably is sucking the smoke smell into the system, in fact I KNOW thats what its doing.

The issue is in our other house we had a similar setup with an earth stove and never had the issue, things done the same, never ran heat, and only AC etc..

There is nothing outside burning, we are rural on 100 acres etc.... And the smoke smell only comes when we turn the AC on. Mind you its not a new smell, its the burned smell... IE inside of the stove.

It really seems like there is something open on the stove or not sealing well that allows it to pull draft out of the stove and hence the odor.

We had a decent weekend, and didn't have the AC on, opened the windows to get the smell out. and all was good. As soon as the AC had been on MOnday night you could smell it in the house.

Another tidbit... we have 3 dogs with us and keep about half the house closed off IE doors shut, so they can go out the doggie doors but not get into the den,kitchen etc... at night in case they are dirty... they only access the porch, utility, master bath and master bedroom...

The one door going into the den has about an inch gap under it and when the AC runs I can feel that draft sucking under the door... may have to cut a vent into that door or leave the doors open and put gates up??

I'm gonna try to get hold of the folks we bought the stoves from years ago... still open but earth stove is out of business...

Thanks, Jeff

The only "fresh" air supply to the stove is another flap on it allowing it to draw interior home air for combustion, other than that its an 8 inch metal pipe in to a 12x12 clay chimney thats over 4 feet above the ridgecap.

I'm no expert, but I do have a thought on this. Since the return is located in the room with the wood stove, couldn't the ducts be holding the smoke odor and bringing it into the rest of the house when the AC is running? Kind of like a car that was owned by a smoker. You can really smell the stale cigarette smell when you turn on the AC and/or heater. Maybe you just need to have the ducts cleaned. Just a thought anyway.

Bob

Sounds to me like when the A/C is running it's creating a negative pressure in the house. Especially in the area with the large central return air.

This can happen. Especially when some rooms are closed off. Your furnace blower is pushing out air and it has to get that air from somewhere. When doors are closed to rooms that have supply registers/grills, it reduces the amount of readily available return air to the furnace, especially in a system with only a central return air grill versus a system with return air grills in each room (except kitchens and baths, for odor reasons).

The quick test would be to make sure the chimney damper on your wood stove is closed tightly. I would also crack open a window a little bit in the room with the central return air grill. I'm betting that when the A/C kicks on and the damper on the wood stove is shut, you'll notice some air from outside being sucked in through the slightly open window.

If this proves out, opening up those closed off rooms should help this problem, along with shutting the damper on the wood stove chimney.

Hope it works.

Scott.

Just got about the same info from my AC guy.

Stove folks didn't have a clue...

I guess we'll have to figure it out... were trying to only cool the rooms we use... since it gets well into the 100s here cooling costs can kill ya....

Jeff

BTW I will do the window thing, but I suspect the clue lies in the fact that when the AC kicks on there is a HARD draft under the one door coming from the utility that has about a 1 inch gap from the vinyl flooring to the bottom of the door....same thing as the window more or less...

Its either open doors or install louvered vents which I have for the one area... long story there but for security we want the one door locked at night to another part of the house....

May have to think about louvered openings in a few other doors to circulate better.

Be careful trying to cool a smaller area than the system is sized for. It could cause icing up of your evaporative coil.

+1 on the louvered grilles in the doors. That should help.

Good luck, hope you get it all worked out.

I"m aware of that cooling issue, not really any different than when Grandma was there ... and soon to have a garage made into game/exercise room that will add more cooling to the unit so should be fine.

Time will tell as this will be the first "summer" in this house.