Too much draft?

[JohnnyG]

Is it possible to have too much draft? I have a 3 inch round 17 feet long chimney liner.

I remember someone saying that their heat output is around 300 degrees. I have a thermometer in my vent and it is reading 185. That is with the stove running on Auto MH.

Besides the low output reading, another thing that makes me think I may have too much draft is that even with a setting of -5 the flames will wrap over the top as if they are getting pulled.

Thanks in advanced.
John

 

[DexterDay]

Lots of AE owners here to help (Lots!!).. With all the different settings there are for that unit, I am sure there is a configuration that will work in your situation.

As for output temps, every stove varies and reading with a digital device will yield better results than the thermo you are using.

 

[Phil Do's fire.]

Don't sweat the output temp, adjust the stove to match the draft

 

[kinsmanstoves]

We never us 3" on a liner, all liners are 4"..

Eric

 

[JohnnyG]

I checked with a couple of different installers here and all use 3" for a 17' straight run and none use OAK???
I guess I could use the 3" that is there for the OAK and install a 4" as the exhaust. If there is too much draw, wouldn't a bigger exhaust exasperate the problem?

John

 

[SmokeyTheBear]

Is it possible to have too much draft? I have a 3 inch round 17 feet long chimney liner.

I remember someone saying that their heat output is around 300 degrees. I have a thermometer in my vent and it is reading 185. That is with the stove running on Auto MH.

Besides the low output reading, another thing that makes me think I may have too much draft is that even with a setting of -5 the flames will wrap over the top as if they are getting pulled.

Thanks in advanced.
John

Yes it is possible to have too much draft the result is usually no fire as in it gets effectively blown out, the pellets burn up too fast and the fire goes out, the fire in this case tends to be a short fierce blow torch one.

Your description is more one of a lazy fire (lack of air) than too much but it may be just fine.

Now exactly where in your vent is that thermometer? At the top of the vent it will be a lot lower than at the back of the stove. Or are you talking convection air outlets into the room that is going to depend on a lot of factors and you should not be comparing your stove temperatures to one burning a different pellet at a different setting on a different model of stove.

 

[Xena]

I checked with a couple of different installers here and all use 3" for a 17' straight run and none use OAK??? I guess I could use the 3" that is there for the OAK and install a 4" as the exhaust.

Don't know about your draft question. We used 4" for our up the chimney vertical liner
because the stove install manual said any run over 15' required 4" pellet vent.

 

[JohnnyG]

According to my manual, at sea lever you can use 3" or 4" up to about 28 feet. I am about 300 feet above sea level and my run is 17 feet. I should be fine with 3 inch.

 

[DexterDay]

According to my manual, at sea lever you can use 3" or 4" up to about 28 feet. I am about 300 feet above sea level and my run is 17 feet. I should be fine with 3 inch.

Your EVL is only 13.5' and 15' is the max for 3". I doubt its the venting.

What setting are you running on? (Hardwood, Softwood, Sunflower, Etc)

Also, a thread title with the Stove name, attracts more users of that model.

 

[Don2222]

According to my manual, at sea lever you can use 3" or 4" up to about 28 feet. I am about 300 feet above sea level and my run is 17 feet. I should be fine with 3 inch.

Nice Chart, you are correct.
However, you cannot go wrong if you always use 4" diameter also!

There is also another good reason for 4" liners according to my chimney man. He says liners get coated up with pellet dust. Therefore if you have a 4" with a layer of ash, it is not nearly as bad as a 3" with a layer of ash in it!

Click to enlarge chart below.

 

[JohnnyG]

a thread title with the Stove name, attracts more users of that model.

Good pointer.

I am running on Softwood. I have not played much with the settings.

I gave the stove a real good cleaning today, the temp as dropped down to 155.

SmokeyTheBear, the thermometer is an equipment thermometer with a 12 inch probe. I am sticking it about 6 inches into the center of the vent that delivers the hot air to the room.

How can you tell it you have a lazy fire?

John

 

[john193]

How can you tell it you have a lazy fire?

John

Open the door, just half an inch will be enough, and see what a lazy flame will look like. It literally looks lazy and burns dark orange with dark tips.

The fire out of the pot constantly changes height on the Mt. Vernon, are you saying that at a feed rating of "-5" you are constantly getting high flame? Upping the feed rating does not drastically change the flame height and the fact that you are getting low numbers on -5 just says to me that your stove isnt feeding enough fuel into the fire. I find people are overly concerned with this number, your flame height is your feed rating. If you have it scaled all the way back, you are telling the stove to dump as less fuel as possible.

Just to give you an idea, I typically set my feed rating at 2 and run on medium output. On colder days, I bump it to 3 and I can typically get away with running the stove on medium and keep the house at the same temp.

If i'm not mistaken, you had said you were burning Hamers, correct? Switch your stove back to hardwood, I found that on softwood I wasnt getting the same heat output as on hardwood. At the center of the vent on medium output (and the feed settings at 3) my IR thermometer reads 300F+ and the sides about 50 degrees cooler.

When you cleaned the stove, did you remove the baffle and get into the 2 exhaust ports on the bottom with a crevice tool?

As a side note, my liner dimensions are comparable to yours.

 

[SmokeyTheBear]

Good pointer.

I am running on Softwood. I have not played much with the settings.

I gave the stove a real good cleaning today, the temp as dropped down to 155.

SmokeyTheBear, the thermometer is an equipment thermometer with a 12 inch probe. I am sticking it about 6 inches into the center of the vent that delivers the hot air to the room.

How can you tell it you have a lazy fire?

John

Was wondering because the term vent is equivalent to exhaust system. And as I said you have to compare like things if you are measuring just temperatures and there are a lot of things have to be exactly the same to make any comparison meaningful.

You are measuring convection (room, distribution) air temperatures.

 

[JohnnyG]

Open the door, just half an inch will be enough, and see what a lazy flame will look like. It literally looks lazy and burns dark orange with dark tips.

Good test, thanks for the tip. I would say that I do not have a lazy flame.

The fire out of the pot constantly changes height on the Mt. Vernon, are you saying that at a feed rating of "-5" you are constantly getting high flame?

I run my stove in Automatic. The flame goes up and down depending on the temperature difference (thermostat setting to room actual). I set the flame height according to the manual (Manual Mode & heat output level to HIGH.) Even at -5 the flames go over the top of the baffle.

Upping the feed rating does not drastically change the flame height and the fact that you are getting low numbers on -5 just says to me that your stove isnt feeding enough fuel into the fire. I find people are overly concerned with this number, your flame height is your feed rating. If you have it scaled all the way back, you are telling the stove to dump as less fuel as possible. Just to give you an idea, I typically set my feed rating at 2 and run on medium output. On colder days, I bump it to 3 and I can typically get away with running the stove on medium and keep the house at the same temp.

I just set the feed rate to zero just to see what happens.

If i'm not mistaken, you had said you were burning Hamers, correct? Switch your stove back to hardwood, I found that on softwood I wasnt getting the same heat output as on hardwood.

I did that last night. Tonight it is burning at 200 degrees.

When you cleaned the stove, did you remove the baffle and get into the 2 exhaust ports on the bottom with a crevice tool?

Yes I did. And I scrubbed the whole firebox, fire-pot, baffle and heat exchanger with a brass wire brush.

 

[JohnnyG]

Here is a bit of an update. Since turning the feed rate to zero (from -5), there seems to be much less ash in the bottom of the firebox.

 

[john193]

Are you getting more heat?

 

[JohnnyG]

Are you getting more heat?

Yes, the thermometer is reading 205 now and the room does feel warmer.