oak and cold air=ash cakes

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Gavin641774

Gavin641774

Member
Dec 4, 2014
55
Iowa
I have been having trouble with ash cakes when it gets below 20°F so last night I disconnected my oak and now no more ash cakes,my oak pipe which is flexible exhaust pipe for automotive use(wanted something rigid) goes up 4 feet and then out through my wall thimble will start to sweat at temperatures around 20°F, so disconnected and no more cakes was thinking about getting heat tape and wrapping it with that because I love my Oak.Any thoughts?
 
Are you sure there is no snow blocking it?
 
I'm not sure but I don't think heat tape would add much heat to make a difference. If you do it I would love to hear the results if you do.
 
I agree - cold and damp Oak air = caked ash in the burnpot. That is why I use Selkirk DT and No More Caked Ash in the BurnPot for ME! ! !
 
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I know the Selkirk DT was a little on the expensive side when I seen it ,and I don't really think that heat tape would would be enough heat either but it would be worth a try,and yes Money my oak is about 6 feet off the ground,I was thinking.., the shorter oak would have to be better,but I hated to drill another hole in the house so drilled one in the thimble,I know that the oak going 4 feet up and out though, will draw enough condensation to make the floor wet below the intake and the moisture is just being drawn into the stove,so not good at all,wonder if the guys who have oaks straight out the wall and not 4 feet up have a lot of condensation too.
 
If the OAK is condensating it doesn't mean the combustion air is damp necessarily. More than likely it means the indoor air has more moisture. The 20 degree air is saturated inside but I highly doubt it is outside. The moisture is from inside the house. Just like if you have a humidifier turned up to high inside and your windows start to sweat. If it is making a difference it would seem to be the temp of the air.
 
What I'm trying to say is that it is the moisture from inside of the house that is causing this. You have more moisture in the home than outside, even if there is a lower humidity. When the OAK cools enough it will condense the moisture from inside the house . Unless you have leaks in your OAK there shouldn't be moisture on the inside, if that air is separated.
Another way of saying it is if you are running with no OAK your combustion air is warmer and damper.
So if this getting rid of the clinkers it is beacuse of the warmer air or something else unknown but not from drier air.
Another example is if you tell me what temperature it starts to condense on the OAK and the indoor temp I could tell you the RH in your home.
 
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I understand what you say pageyjim,but the humidity in the room is 20%.this is an attached garage I have on my hose(15x25) that the pellet stove is in,yes believe it or not with just a walk in door going from garage to the 32x60 house it keeps the same temp (sometimes turning the stove on 3)when it gets really cold the oak will actually collect ice on it,I would think it would probably be how long your intake is as pellet stoves do actually draw quite a bit of aired. Do you have an oak,if so is it straight out the wall or up and out,just wondering the more input the better,I understand about relative humidy and condensation but the air the pellet stove is bringing in through the length of the pipe,I would think that's why I have alot of condensation.
 
There can be more moisture in a room at 70 degrees and 20% RH than 40% at 20 degrees. That is just a guess but you get the idea. In any event the condensation, moisture is coming from the conditioned room not outside. You can insulate the OAK. I would try some insulating tape or some high velocity flexduct used in HVAC if it is causing a mess. The flexduct means rerunning the OAK . The uninsulated OAK may be stealing a little heat too. I don't know if a longer OAK with elbows would effect it in this case. I can see it lowering velocity, volume etc.
I have an OAK it is straight more or less and about 2-3 ft. I do get clinkers. Only time I didn't was when I was burning Greene Gold Pellets. That seems to be the best I can get. I have also used Green Supreme, Stove Chow, Freedom Fuel and another one from TSC I can't remember right now. I always attributed the clinkers to problems with air leaks and the pellets.
 
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That seems to be the common culprit is the pellets are crap on most of the posts that you see on here however the damp air was never to blame.Thanks for your input pageyjim.Yes the oaks could be to blame for a lot of bad burning pellets, as you see on here there is allways someone discussing ash cakes when the weather gets cold.Just thinking I need to heat my oak intake tube.
 
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Yeah that's my best guess too.

Just to go back to your condensation issue. with your example of 20% RH. I plugged in 70 degrees as a guess and the dew point at that level is 27 degrees. So with indoor conditions described above you will condense at 27 degrees. There is more moisture in that conditioned room than most would think.
 
And pageyjim,I am not sure how hot heat tape would get?maybe heat tape then insulate,I don't know?Try it on yours then let me know LOL.
 
I thought of it too and dismissed it. The air would be moving to fast to pick up any heat. The tape is meant to stop water from freezing. The Selkirk DT concentric kit may work some and I'm not sure how much. Remember moisture doesn't seem to be the problem because the outdoor air is more than likely dryer. If anything makes a difference from what you have witnessed it may be the temp. of the combustion air. Insulating won't warm the combustion air either it will keep it colder in fact. Insulating will keep it from condensing.
 
Can someone tell me why some have Condensation issues while Having an OAK and others like myself
are Always bone dry inside around the OAK tube.
 

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Could be a dry home with lots of leaks is one possibility. Are you implying that yours is heated from your exhaust vent? Which I think is the case.
 
Think I will start with just insulating the oak and then go from there,give everything a shot until I get it figured out,something to think about though,don't blame it on the pellets for clinkers until you know what your stove is taking in
 
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pageyjim said:
The horizontal flap on pic#2 under the cleanout looks to be it. I'm sure he was going to tell you but I don't see the need to wait lol. Or maybe I'm wrong.
Click to expand...
yes...under the flap is a row of small holes bring in the Outside air..
with the exhaust right next to the OAK tube I assume it picks up the heat...
 
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