Thinking Wood Gun...any advice or experience?

[Gasifier]

I made some adjustments to the cycle timer. Now I have it set for 2 trips (~4 mins) every hour. I lost fire yesterday at some point so I made the adjustment.

Overslept a bit this morning and woke up to a cold boiler. Started a fire and warmed it up. Apparently on the next automatic restart attempt we had a pretty good puff back. Got the smoke detectors going and the dog freaked out.

Has anyone piped their intake outside? Do I have to come DOWN 24" on the intake before heading outside? Ideally I would be able to stay up high and run along the ceiling outside.

ac

I have not piped my intake outside. If it is in your basement I would leave it drawing air in from there. I would not want cold air from outside coming into the boiler when it is really cold outside. I think it would be better for your 60ish air in the basement to be taken into the boiler.

As far as a cold boiler goes. I have had an occasional "bridging effect" because of a larger split holding up the other wood and the coals burning right out from underneath it. You have to watch out for that as well.

 

[avc8130]

I have not piped my intake outside. If it is in your basement I would leave it drawing air in from there. I would not want cold air from outside coming into the boiler when it is really cold outside. I think it would be better for your 60ish air in the basement to be taken into the boiler.

As far as a cold boiler goes. I have had an occasional "bridging effect" because of a larger split holding up the other wood and the coals burning right out from underneath it. You have to watch out for that as well.

What do you feel the concern is with cold air? A lot of stoves run OAK. Cooler air has more oxygen...isn't that a good thing? It looks like the manual requires that the intake be brought to the floor first and then back up and out. That makes sense to me. This would also create a bit of a heat trap.

I haven't experienced bridging yet. I just haven't been putting in enough wood/reloading often enough. I do notice that the wood load won't all make its way over the nozzles. I think the diameter of the refractory in my 180 is a bit bigger than the 100/140s and a bit of the wood load remains off the nozzles as the charge burns near the end.

ac

 

[Gasifier]

What do you feel the concern is with cold air? A lot of stoves run OAK. Cooler air has more oxygen...isn't that a good thing? It looks like the manual requires that the intake be brought to the floor first and then back up and out. That makes sense to me. This would also create a bit of a heat trap.

I haven't experienced bridging yet. I just haven't been putting in enough wood/reloading often enough. I do notice that the wood load won't all make its way over the nozzles. I think the diameter of the refractory in my 180 is a bit bigger than the 100/140s and a bit of the wood load remains off the nozzles as the charge burns near the end.

ac

I may be wrong ac. I am no expert that is for sure. But I believe that cold air coming into your boiler is like cold wood coming into your boiler. I want warm air and warm wood coming into the boiler. It just seems like if you want the fire and boiler to be hot, which I do, then why add freezing cold air or freezing cold wood. There is always going to be moisture in the wood. And if it is 10 degrees outside then the moisture is frozen. Requires energy to thaw it and then get rid of the moisture. I try to bring my wood inside at least two full days ahead of when I am going to put it in the boiler. The air in my basement is usually at least 70 degrees. Hopefully others will give you their opinion on this. Let me know how that cycle timer works out for you. Has it been kicking it on every hour now?

 

[avc8130]

I may be wrong ac. I am no expert that is for sure. But I believe that cold air coming into your boiler is like cold wood coming into your boiler. I want warm air and warm wood coming into the boiler. It just seems like if you want the fire and boiler to be hot, which I do, then why add freezing cold air or freezing cold wood. There is always going to be moisture in the wood. And if it is 10 degrees outside then the moisture is frozen. Requires energy to thaw it and then get rid of the moisture. I try to bring my wood inside at least two full days ahead of when I am going to put it in the boiler. The air in my basement is usually at least 70 degrees. Hopefully others will give you their opinion on this. Let me know how that cycle timer works out for you. Has it been kicking it on every hour now?

Interesting idea. I wonder how much energy would really be spent to use 0F outside air vs 70F basement air. The specific heat of air is so low, I bet it isn't much.

I bring my wood inside also. I have been keeping ~1/8 cord inside at a time for now. I just put the last of my first 1/4 cord through the boiler this afternoon.

ac

 

[avc8130]

I have been thinking lately, I have an old school Fluke Type K thermocouple setup. It uses very small wire lead.

Think it would be ok to put in one of the side gassification chambers and sneak it out through the lower door?

I'm just so curious.

ac

 

[Woodsrover]

...I believe that cold air coming into your boiler is like cold wood coming into your boiler. I want warm air and warm wood coming into the boiler. It just seems like if you want the fire and boiler to be hot, which I do, then why add freezing cold air or freezing cold wood.....

I understand your point but if you're drawing your intake air from inside the house, that air still has to be made up by bringing cold air into your living space through any little cracks in the sills, door frames, window sills, etc. I'd rather pull the air right into the firebox than throughout the house. As you know, these things pull in a lot of air.

 

[avc8130]

I understand your point but if you're drawing your intake air from inside the house, that air still has to be made up by bringing cold air into your living space through any little cracks in the sills, door frames, window sills, etc. I'd rather pull the air right into the firebox than throughout the house. As you know, these things pull in a lot of air.

The WG seems to need every bit of the 5" duct! In my basement, I bet it gets most of its air through my 2 single pane steel framed windows and old wood door to Bilco doors. At the moment I have one of the windows open to combat the smell.

ac

 

[Gasifier]

I understand your point but if you're drawing your intake air from inside the house, that air still has to be made up by bringing cold air into your living space through any little cracks in the sills, door frames, window sills, etc. I'd rather pull the air right into the firebox than throughout the house. As you know, these things pull in a lot of air.

Not me. The five inch pipe is closed off by the damper by almost 80%. At least mine is anyway. Yes, it does draw in air from outside. A little fresh air into the house never hurts. Yup, it does work against heating the house a little. I don't want cold air or cold wood going directly into my boiler. My house is large. If I was in a small, really tight house, that may be different. But I would still want to pre-heat it some how.

 

[muncybob]

Mike, as ac stated you don't need to worry about over firing with the timer as long as your high set point is 200 or less. With that said, you may experience the back-puff(or whatever it's called) if the timer kicks in too soon after a burn. It's rare but is has happened to us.
Wiring the exhaust fan to the purge timer had also crossed my mind too...a good idea ac.

 

[avc8130]

Not me. The five inch pipe is closed off by the damper by almost 80%. At least mine is anyway. Yes, it does draw in air from outside. A little fresh air into the house never hurts. Yup, it does work against heating the house a little. I don't want cold air or cold wood going directly into my boiler. My house is large. If I was in a small, really tight house, that may be different. But I would still want to pre-heat it some how.

What lead you to having your damper 80% closed?

 

[avc8130]

Mike, as ac stated you don't need to worry about over firing with the timer as long as your high set point is 200 or less. With that said, you may experience the back-puff(or whatever it's called) if the timer kicks in too soon after a burn. It's rare but is has happened to us.
Wiring the exhaust fan to the purge timer had also crossed my mind too...a good idea ac.

I had that happen. Threw enough smoke through the intake to set the smoke detector off. Had a mad dash to the basement. The dog was the most upset. She is TERRIFIED of the beeping.

This is what lead me to want to pipe the air intake outside.

ac

 

[Gasifier]

What lead you to having your damper 80% closed?[/quote

You just talked about it in your post. Puffing. Having the damper closed down 80%, or even closed all the way, helps prevent the puffing that comes with dry wood. Sometimes the Gun is getting too much air. I don't think bringing the air in from outside is going to prevent that. I may be wrong, I certainly have been in the past!

 

[avc8130]

I didn't think bringing the air in from outside would prevent the puff...but if a puff did occur, hopefully the smoke would go outside rather than into the basement.

ac

 

[Gasifier]

I didn't think bringing the air in from outside would prevent the puff...but if a puff did occur, hopefully the smoke would go outside rather than into the basement.

ac

This is true. I wasn't thinking about that. LOL. After some trial and error and talking to other Wood Gun owners in the boiler room I found that having my damper closed almost all the way prevents almost all puffing. If I get some really dry wood in there, or their was more wood than necessary in there that dried out and the boiler went into idle then I may get a puffing when it lights up. But it is really rare now. How is that cycle timer working? I am curious as to why you are still getting that smell. Is that just from the puffing you had? Or are you getting a creosote kind of smell? Your wood is certainly dry enough. Most of my wood is from 17 - 22%, roughly.

 

[avc8130]

This is true. I wasn't thinking about that. LOL. After some trial and error and talking to other Wood Gun owners in the boiler room I found that having my damper closed almost all the way prevents almost all puffing. If I get some really dry wood in there, or their was more wood than necessary in there that dried out and the boiler went into idle then I may get a puffing when it lights up. But it is really rare now. How is that cycle timer working? I am curious as to why you are still getting that smell. Is that just from the puffing you had? Or are you getting a creosote kind of smell? Your wood is certainly dry enough. Most of my wood is from 17 - 22%, roughly.

Well, the puff back closed the damper off. I opened it back up ~1/2 way.

The cycle timer "works". IE, it spins and turns the boiler on whenever it trips on the jumpers. I haven't lost a fire since (assuming I had enough wood). I have also proven that the high limit aquastat works to cut off the boiler. I think 5 mins/hour might be a bit often. My heat demand today kept the boiler active enough that the cycle timer pushed to the high limit. Interestingly enough, when the high limit kicks in it also stops the cycle timer from rotating until the boiler drops below the differential temperature. Then the cycle timer starts again and boosts it back up. It's a bit of a cycle.

I think the smell I have is creosote-like. I have had a few drips from the draft fan area, but that was mostly during the first fire up of the boiler last Monday.

ac

 

[Gasifier]

Well, the puff back closed the damper off. I opened it back up ~1/2 way.

The cycle timer "works". IE, it spins and turns the boiler on whenever it trips on the jumpers. I haven't lost a fire since (assuming I had enough wood). I have also proven that the high limit aquastat works to cut off the boiler. I think 5 mins/hour might be a bit often. My heat demand today kept the boiler active enough that the cycle timer pushed to the high limit. Interestingly enough, when the high limit kicks in it also stops the cycle timer from rotating until the boiler drops below the differential temperature. Then the cycle timer starts again and boosts it back up. It's a bit of a cycle.

I think the smell I have is creosote-like. I have had a few drips from the draft fan area, but that was mostly during the first fire up of the boiler last Monday.

ac

AC,

I don't know what your going to think after I tell you this! After telling you that with my damper being closed I had all but eliminated the back puffing I was getting ready for bed and went down to fill the boiler. I could here that sound again! When I got to it my boiler was chugging away like a steam locamotive! It had just the right conditions I guess. I had to turn the fan on and open the door with my cleaning tool ready and shift the load so that everything fell over and covered the nozzle. The wood had dried out enough and there was enough of a space around the back end of the nozzle that the fire was just a screamin but was creating that chugging (puffing) again. With only a little over one full year with the boiler, I am still learning as well. Happy burning.

 

[avc8130]

AC,

I don't know what your going to think after I tell you this! After telling you that with my damper being closed I had all but eliminated the back puffing I was getting ready for bed and went down to fill the boiler. I could here that sound again! When I got to it my boiler was chugging away like a steam locamotive! It had just the right conditions I guess. I had to turn the fan on and open the door with my cleaning tool ready and shift the load so that everything fell over and covered the nozzle. The wood had dried out enough and there was enough of a space around the back end of the nozzle that the fire was just a screamin but was creating that chugging (puffing) again. With only a little over one full year with the boiler, I am still learning as well. Happy burning.

I have read about this "chugging" but have yet to experience it. I thought it was caused by lack of sufficient oxygen?

The "puffing" I was referring to happens when the boiler is in standby with the damper closed and fan off and it turns on. As the damper opened, the fresh air sucked in and ignited the wood gas. It quickly expands quicker than the fan can pull it down through the nozzle and shoots out the intake.

ac

 

[avc8130]

I guess my cycle timer settings weren't good enough. I came home to 90% of the wood load I put in at 6AM today. Dead. Cold. The boiler was "on", but temps were dropping and it was near the low temp cutoff.

I added an extra "clip" each hour. I'll try ~6-7 mins hourly now.

ac

 

[mikefrommaine]

Careful, you are getting dangerously close to making your wood gun idle. You might have upset the fire starting elves.

 

[avc8130]

Careful, you are getting dangerously close to making your wood gun idle. You might have upset the fire starting elves.

LOL. I'm honestly not sure what happened. The SLIGHTEST bit of flame from the propane torch and we were off and running.

The cycle timer doesn't really "idle". Instead it is like a WOT 1/4-mile run every hour.

ac

 

[mikefrommaine]

The cycle timer doesn't really "idle". Instead it is like a WOT 1/4-mile run every hour.

ac

Hate to break it to you but that is pretty much the definition of idleing. Welcome to the land of the mere mortal wood boiler owners.

I have mine set to do a 5 sec wind sprint every 20 minutes.

 

[JP11]

Hate to break it to you but that is pretty much the definition of idleing. Welcome to the land of the mere mortal wood boiler owners.

I have mine set to do a 5 sec wind sprint every 20 minutes.

Not even sure WHAT mine does.. but it's something every once in a while. Controller says MAX on it. I'll leave it to "HAL" to take care of the burn.

JP

 

[avc8130]

Hate to break it to you but that is pretty much the definition of idleing. Welcome to the land of the mere mortal wood boiler owners.

I have mine set to do a 5 sec wind sprint every 20 minutes.

Whatever helps you sleep at night. If the boiler idled, it wouldn't need the cycle timer. I liken it to my car. When I leave my car idling, it will sit there until it runs out of fuel ready for me to drive it. It doesn't require an outside source like a battery and me to turn the key to get it to start. This is what the cycle timer does, it allows the oxygen back to the party and forces draft.

Who knows, maybe the elves just took a day off?

Call it whatever you will, I really don't care. This fire goes OUT if there isn't enough demand, whether it runs out of fuel or not.

Now to just figure out the proper amount of "WOT" to keep it happy.

ac

 

[Woodsrover]

6 minutes every 120 minutes seems to work for me.

Matter of fact, until it gets below 30-degrees this is enough fire to satisfy any demand I have for heat or hot water. The boiler doesn't fire on a lot-temp demand until it gets below 30 or we're doing a bunch of laundry.

 

[avc8130]

6 minutes every 120 minutes seems to work for me.

Matter of fact, until it gets below 30-degrees this is enough fire to satisfy any demand I have for heat or hot water. The boiler doesn't fire on a lot-temp demand until it gets below 30 or we're doing a bunch of laundry.

I would say my house is similar at ~40F. I'm not sure why laundry is taxing your boiler. We do all of ours in cold water.

ac