Alderlea blowing in cold air! Solutions?

[Sooz]

This is our first winter burning our Alderlea stove, and we love it - along with the incredible service we've received from Tom the Chimney Sweep! However one thing we've noticed that is problematic is that cold air blows in along the air control lever slot - and it even happens when the stove is blazing hot! (It also happens more when the lever is closed - all the way to the right.)

We'd never intended to use the stove as a primary heat source (we're the ones burning drift wood on Alaska's treeless coast), and we're finding that it's really cooling that part of the house down when it's not in use. My husband installed the outside air intake straight down through the floor into the protected but unheated crawl space under our house, so it is shielded from the wind - and not at all easy to get to. It's already been -10 here this winter, with colder temps to come, and we already have drifts on all sides of the house. I noticed the other morning that there was frost built up on the outside of air intake pipe under the stove, and frozen condensed droplets of water on the underside of the ash pan.

We're not sure why this is happening, although my husband's theory is that our house has enough air leakage that as warm air escapes it's drawing in cold through the stove, although I think our house is reasonably tight. Has anyone else had this problem? We can't get to the air intake opening in the crawl space to plug it when we're not using it; and even if we re-routed it out the side of the house the drifts would eventually cover it and make it difficult to get to.

At this point the only solution appears to be to disconnect the pipe and just let the stove draw air from within the house. Does anyone see any reason not to do this? Does anyone have any other suggestions?

Thanks so much

 

[littlesmokey]

I would consider this an extreme conditions. Let's explore possible reasons, with as much information as possible. What appliances or services draw air from the house. Like bath fans, clothes dryer, range hood, etc. How tight is the attic? Do you have a chimney that is not used? Do you have a block-off plate for the stove stack? Is it insulated to reduce passage of air? What kind of primary heating? Does it have air handlers that may run through unheated spaces? Do you have an OAK for the furnace?

Don't think I have heard of the freezing condensation on the stove, but on the pipes, maybe. Sounds like humidity is not an issue except too much.

When I lived in Upstate New York I closed part of my second floor off my first winter. That was until I went in to get a book and found a quarter inch of ice on the window, both the inside and the outside cold weather storm window. It was cold then, -23. Learned my lesson.

 

[LLigetfa]

I ran into the same sort of issue and added a positive shutoff.

https://www.hearth.com/talk/threads/42594/

 

[madison]

? Is this an Outside Air setup ? If yes, and I read your complaint coorectly, I think that for whatever reason, (for instance, location of the outside air source), the outside air supply is "pressurized" and supplying more air than the stove requires. I would disconnect it from the stove, stuff the outside air source with insulation, and use the stove without the outside air kit.

 

[Sooz]

Thank you for your interest!

LLigetfa, the thread you provided a link to has lots of interesting ideas - thank you!

Littlesmokey, we don't have a furnace. Our only other heat source are two Monitor oil stoves (which did the trick until we put the stove in.) We also have cathedral-type ceilings in most of our small, one story house, so not much of an attic to speak of. Our air vents are one kitchen vent, one bathroom vent, one dryer vent, and a plugged old oil stove chimney. I don't know what a "block-off plate for the stove stak" is. If it's a damper - no, we don't have one in our Alderlea stove pipe. We were advised against needing one. It's a well-insulated stove pipe, as well.

If this gives you any more ideas, bring 'em on!

Thank you so much for your thoughtful and helpful suggestions!

Sue
Nome, Alaska

 

[madison]

"My husband installed the outside air intake straight down through the floor into the protected but unheated crawl space under our house, so it is shielded from the wind - and not at all easy to get to."

The problem most likely is with your husband's install of the outside air kit.

"cold air blows in along the air control lever slot - and it even happens when the stove is blazing hot! (It also happens more when the lever is closed - all the way to the right.)"

Repeat. I would bet that the problem most likely is with your husband's install of the outside air kit. The area below you home must be pressurized to some small amount, snow, wind whatever.

I would try disconnecting the outside air kit at the stove, stuff the tube with insulation, and I will bet that the stove will not blow cold air.

 

[littlesmokey]

Sue, I think you have a negative air problem. Use of the powered vents are drawing the air through the OAK. Like others have said, relocate the line and put a shut off in it. I would use a stainless gateway (used in dust collector installations) Be sure you have it closed after your stove cools. Sounds like you have a stove pipe stack and not a chimney insert, the block off plate doesn't apply, but you should make sure the thimble around the pipe is tight. Don't pack insulation around it , unless it is non-flamable. I would also suggest a damper on your drier stack and each of the ventilators. You have a much more serious cold air infiltration problem than most of us can imagine. My worst winters on the hill had lows warmer than your highs. Good luck and keep us up to date on solutions.

 

[GeneralBill]

If your home does have negative air pressure due to bath fans, etc, then the outside air will come from another location (else the air cannot exhaust). Sometimes the other locations are not as desirable as the area near your stove.

I drilled small holes to the crawlspace near my central air intake so it pulls fresh air there instead of through the wall/floor seals, etc. My fan runs on low constantly.

- Bill

 

[GeneralBill]

Oh, another idea: you can use the same 4" OAK ducting to make a "U" shape in the crawlspace -- which I plan to do. This might help as it will make a trapped space of cold air, which impedes the chimney effect.

- Bill

 

[Hogwildz]

OH my, an OAK that actually isn't so great, imagine that.
The fix is easy, oull the AOK pipe off the back of the stove and pull it out, then fill the hole through to the crawl space.

 

[littlesmokey]

Oh, another idea: you can use the same 4" OAK ducting to make a "U" shape in the crawlspace -- which I plan to do. This might help as it will make a trapped space of cold air, which impedes the chimney effect.

- Bill

Bill,
Do you want to re-think this one. P-traps work in sewer drains because the air can not travel through the block made by water in the crook. How does that work with no water?

 

[begreen]

Hey Sue, thanks for the update. One thing I don't understand is how one can have periods of the stove not running when it is that cold outside.

What are the winds like when this happens? What we are trying to understand at a distance is whether there is positive pressure, most likely from wind, on the crawlspace, or negative pressure (suction) in the house. I'm going to guess it is the second, but could be wrong. Negative pressure can have multiple causes or just one. When a place is sealed tightly, then anything that has an outlet to the outside is suspect. Examples would be a bathroom or kitchen exhaust fan, a clothes dryer, etc. Another cause could be a competing appliance like a boiler, hw heater or furnace. And last, it could be the house itself. If there are opening above to the attic or roof vents, air can be pulled upward by convection. You will have to tell us what you see.

I'm hesitant to recommend running the stove without the OAK until the issue is understood. If this is due to negative pressure, removing the OAK could just change the problem. Best to understand the reason behind the issue. Otherwise, if this is neg pressure, without the OAK, the stove might start drafting poorly or worse yet, reversing draft at some point. That would be bad. But maybe not. Some places are leakier than one might imagine.

Part of the problem is the stove design itself. PE's OAK is not a sealed unit to the fresh air intake. It just floods in air behind the ash pan, so here's what I would try. Remove the ash pan. It's pretty useless and will be in the way of the next step. Get a brick and about a 6"x6 piece of sheet metal. When the stove is not in use, cover the air intake at the back of the stove with the sheet metal square and put the brick on top of it. If that works well, then the next step will be to figure out a way to seal the ash pan opening with a flap that allows access to the 'valve'.

PS: I have some ideas for the 'valve', but first we need to determine how effective the 'cure' is. At this point, it's best to keep changes simple, safe and reversible.

 

[Sooz]

Thanks for all the ideas everyone! This is the most helpful and fun forum on the internet!

 

[GeneralBill]

Oh, another idea: you can use the same 4" OAK ducting to make a "U" shape in the crawlspace -- which I plan to do. This might help as it will make a trapped space of cold air, which impedes the chimney effect.

- Bill

Bill,
Do you want to re-think this one. P-traps work in sewer drains because the air can not travel through the block made by water in the crook. How does that work with no water?

P-traps provide better blockage (unless they evaporate or are vacuumed due to circumstance, but that's another post). Keep in mind that the chimney effect relies on a thermal gradient. Say you have a straight thermal gradient, which makes the most air transfer, then you somehow join it with a second equal-sized gradient, making a "U" shape (i.e. two gradients will exist, joined at the bottom) -- this will make minimal chimney-effect transfer. As you cut down one side of the "U", making a "J", there exists a continuum of hot/cold air transfer efficiencies due to the chimney effect. My proposal is really to make a "U" in the crawlspace. This does two things, cold air at the base of the "U" is less likely to be pulled up (I'm guessing!) as warmer air from the top of the intake near my floor boards needs to be pulled down into the "U", and, the extra air resistance created by the tube extension discourages drafts -- which have a lower pressure gradient than the stove air demand.

That's the theory at least! I've been sometimes slapped silly by reality.

- Bill

 

[LLigetfa]

I would bet that the problem most likely is with your husband's install of the outside air kit. The area below you home must be pressurized to some small amount, snow, wind whatever.

Sue, I think you have a negative air problem.

Agreed. I'm glad you came to the husband's defense.

A bit of air coming in while the fire is burning isn't really a bad thing. Nature abhors a vacuum. The house needs its air and the pressure deficit should be addressed. Better to stop warm humid air from leaving the envelope.

 

[LLigetfa]

That's the theory at least! I've been sometimes slapped silly by reality.

Bill,
In theory, theory is the same as reality. In reality, it isn't always.

A P trap for cold air only works when the pressure inside is close to the pressure outside. When leaks in the building envelope are exacerbated by stack effect, there can be enough of a pressure deficit to over-power the resistance of the P trap. Many people with leaky homes go around sealing up everywhere they feel a cold draft but do not address the areas where warm air leaks out, creating a pressure deficit.

 

[Sooz]

Thanks for all the discussion and ideas! My husband and I put our heads together and came with a pretty simple solution that appears to have solved our problem. Being artistic right-brain types it was too challenging to try to determine whether we had a negative air problem or a positive air problem, but we did know we had too much air. My husband cut a 15" strip off the end of a batt of fiberglass insulation and tucked it up into the OAK (extending well into the insulated flooring section) gently enough to maintain a friction fit but still allow for passage of some air. This seems to successfully eliminate the cold air coming in both from the cold and the wind, but still allows for enough air to give the fire all the draft it needs. Currently it's -9 and windchill makes it -18 but only warmth pours forth from our Alderlea stove!

Just love this forum! Thanks all!

 

[Bigg_Redd]

This is our first winter burning our Alderlea stove, and we love it - along with the incredible service we've received from Tom the Chimney Sweep! However one thing we've noticed that is problematic is that cold air blows in along the air control lever slot - and it even happens when the stove is blazing hot! (It also happens more when the lever is closed - all the way to the right.)

We'd never intended to use the stove as a primary heat source (we're the ones burning drift wood on Alaska's treeless coast), and we're finding that it's really cooling that part of the house down when it's not in use. My husband installed the outside air intake straight down through the floor into the protected but unheated crawl space under our house, so it is shielded from the wind - and not at all easy to get to. It's already been -10 here this winter, with colder temps to come, and we already have drifts on all sides of the house. I noticed the other morning that there was frost built up on the outside of air intake pipe under the stove, and frozen condensed droplets of water on the underside of the ash pan.

We're not sure why this is happening, although my husband's theory is that our house has enough air leakage that as warm air escapes it's drawing in cold through the stove, although I think our house is reasonably tight. Has anyone else had this problem? We can't get to the air intake opening in the crawl space to plug it when we're not using it; and even if we re-routed it out the side of the house the drifts would eventually cover it and make it difficult to get to.

At this point the only solution appears to be to disconnect the pipe and just let the stove draw air from within the house. Does anyone see any reason not to do this? Does anyone have any other suggestions?

Thanks so much

Get rid of the air kit.

Also, burning drift wood will cause an untimely demise of your woodstove.

 

[Sooz]

Also, burning drift wood will cause an untimely demise of your woodstove.

We selected a PE because we live on Alaska's treeless western coast, where driftwood is the only other option to wooden shipping pallets (which are in great demand!) and occasional scrap lumber. After lengthy discussion with many on this forum we opted for the Alderlea T5 because of the replaceable stainless steel baffling, knowing that driftwood is hard on stoves. But given our location on the Bering Sea coast, where heating oil is $6/gallon, you gotta do what you gotta do!

 

[begreen]

You go gal. To me it's amazing you survive and thrive up there. We'll see what these PEs are made of when the salt hits the metal. Hopefully you'll be posting satisfaction for many years to come.

 

[LLigetfa]

Also, burning drift wood will cause an untimely demise of you...

(broken link removed to http://www.woodheat.org/environment/garbage.htm)

One of the pollutants that results when paper, plastics and salt water driftwood are burned in a wood stove is dioxin, a highly toxic chemical that doesn't decompose and which builds up in the tissues of animals and humans.

 

[begreen]

Dioxin is a by-product of all wood burning. It's probably in tobacco smoke as well. This is a good reason to burn responsibly and champion clean burning stoves.