Help Wood furnace that spews out black stuff.

[shrtct]

I have a friend who has a furnace that was installed. Oil and wood fired. It spews black stinky goop out of the joints, Now i know this is caused by condesation but how to stop it. We are told to much draft not enough draft to long of a smoke pipe run and so own. From what i know and see i think its during the off cycle were the automatic damper closes and everything cools down. At that time it condensates and then makes the black stuff. Help
Please.

 

[stee6043]

My first bet would be that your friend is burning wood that was not properly seasoned. Burning green wood produces much "goop".

 

[jeff_t]

Stinky black stuff is called creosote. Not a good situation. How dry is the wood? Which furnace is it? Better description of the setup? Pictures?

 

[shrtct]

Yukon HUSKY-EAGLE I
The wood was purchased and stated it was seasoned. The draft is at 3 inchs of wc. the run is 20 feet. with out the damper it is 8 inchs of wc. Temp at breech during run is 500 degrees. what is the best seasoned wood out there. is one year good or should it be longer. now if wood stays out side does it not soak up the moisture. I know nothing about burning wood but i am fully aware of proper draft, proper combustion ect. I fully lic in oil, propane, natural gas ect. Just know nothing on burning wood. i deal with condensation issues everyday. the chimeny is metalbestos. i am thinking of running metalbestos closer to the breech to help on the down time when it is burning low. I do know that you need a certain temp to help with condensation. Ps found out the wood is to be kilmed dried.
Dave

 

[maple1]

3 & 8 inches of wc draft? Sounds like you're out a couple of decimal places on those figures.

One year MAY dry wood - depends on the wood, weather, site exposure. Too many variables to answer yes or no. If wood gets rained on, it will get wetter, but that amount of wetter should dry off relatively quick with a return to drying conditions.

'Stated it was seasoned' - the only way to verify, if you're not familiar with wood, is with a moisture meter. Does it sizzle when put in the flames?

But I'm betting wet wood.

 

[laynes69]

Most of the time when "seasoned" wood is purchased, it's not. A cheap moisture meter can verify this. If there's no call for heat, the furnace will smolder. I would suspect this is what's happening where the full potential isn't needed. There is little that can be done. If the wood is seasoned, then building smaller hotter fires should help. What size is the chimney? At 500 degrees there should be no condensation, what is it when the dampers close? If theres alot of smoke from the chimney, there will be creosote.

One year is okay for most woods to season. Oak requires 2 to 3 years, and ideally 2 years is best for good seasoning. Some cover their piles and others don't. The important thing is it's split and stacked to allow sun and airflow. Then cover if needed.

 

[shrtct]

3 & 8 inches of wc draft? Sounds like you're out a couple of decimal places on those figures.

One year MAY dry wood - depends on the wood, weather, site exposure. Too many variables to answer yes or no. If wood gets rained on, it will get wetter, but that amount of wetter should dry off relatively quick with a return to drying conditions.

'Stated it was seasoned' - the only way to verify, if you're not familiar with wood, is with a moisture meter. Does it sizzle when put in the flames?

But I'm betting wet wood.

Sorry i should of said -.03 -.08 draft not what i typed. Thank you for the reply. The flue is 8 inches metalbestos aswell. can you recommend a brand for the moisture meter.

 

[Sawyer]

You may be better off taking a small center of the piece of wood and put it in an oven to dry. Weigh initial weight and keep heating till it stops loosing weight. It is now dry and you can calculate the moisture content with 100% accuracy.

A moisture meter with pins only measures the moisture content between the pins, not the center of the piece. I have a Wagner electronic, pinless moisture meter. It works great but is over $200. I need it for my sawmill but would not spend that much for one time on firewood.

 

[flyingcow]

Harbor freight has a good cheap meter. Split the wood in half, measure the inside. 20% or less is ideal. If i was buying wood that has been advertised as seasoned, you need a moisture meter. Best thing for your friend to do is buy at least 2 yrs worth of wood the first yr. season it yourself.

 

[jeff_t]

Also, describe the pipe/chimney setup. Any horizontal runs should have at least 1/4" rise/foot, and the chimney connector should be installed with the crimped end down, so that any condensate that forms drips into the appliance.

 

[PassionForFire&Water]

What's the temperature of the flue gasses where they leave the furnace?
when it is below 250F and the fire is smoldering it will condensate on the colder parts of the furnace and flue pipe

 

[shrtct]

Yes the pipe does rise a 1/4 of a inch per foot. The one thing that was not done was the crimped edge. will rotate the pipe. Is there anything you can use to clean the floor.

 

[laynes69]

I recommend a creosote treatment like anti-creo-soot. If there's glazing I would use this before sweeping. I would recommend hot short fires until there's a greater demand for heat.

 

[Fred61]

Yes the pipe does rise a 1/4 of a inch per foot. The one thing that was not done was the crimped edge. will rotate the pipe. Is there anything you can use to clean the floor.

Any good cleaner and a scrub brush will clean up the floor. I buy Mean Green by the gallon at the Dollar Store. I use it for de-greasing in the shop.

As you well know, being an oil technician, moisture is a by-product of combustion and will always be present regardless of wood moisture. If your wood is the correct moisture content the only way to reduce, not eliminate liquid from condensing and dripping is to learn the heat requirements and load the furnace accordingly. Estimate when the appliance will go into idle and load enough wood so when it does idle, the wood has had a chance to be in there long enough to have baked out most of the moisture.

Shortening the length of the single wall will also help

I once ordered a cord of "seasoned" wood from a vendor and he asked what length I wanted it bucked up. It turned out that the "seasoned" wood was cut from the logs that had been in the pile the longest amount of time.

 

[flyingcow]

Good point Fred61. Wood needs to be cut/split/stacked at least for 1 year. Not left in tree length on the ground for a year. Seasoned wood is a relative term?

Grab a few hot dogs and have a little outdoor fire. Chances are, the wood will boil the water out the ends. Not ideal firewood to heat with. Plus, you're going to have a chimney fire soon.

 

[Fred61]

Good point Fred61. Wood needs to be cut/split/stacked at least for 1 year. Not left in tree length on the ground for a year. Seasoned wood is a relative term?

Grab a few hot dogs and have a little outdoor fire. Chances are, the wood will boil the water out the ends. Not ideal firewood to heat with. Plus, you're going to have a chimney fire soon.

Perhaps I should have told him that the seasonings I prefer are salt and pepper.

 

[shrtct]

Lol i do like salt and pepper aswell. I fully understand the combustion process and believe the issue is at a no call for heat or the wood. I will talk to my friend to see about bringing the metalbestos close to the unit. The draft is deffinetly there with out question. In my line of work i deal with codensation issues all the time. But i lso know to that it needs to stay a specific temp to not cause codensation to. What do you guys feel about kilm dried wood.
Dave

 

[flyingcow]

Kiln Dried wood? Be the way to go to start out with the first year. But whats the moisture content? You have to check the MC with a meter. Split it and check it. Just because it's advertised as kiln dried doesn't mean it was left in the kiln until fully dried. And define fully dried?

But for the long haul, buy 2 yrs of wood to start. Suffer the 1st yr with green wood. But after that you know what you got.