Draft door open or closed with AUF

[Wmmaple]

Added a 273 cfm squirrel cage blower to my arch. The arch is not an airtight, it’s natural draft. Any thoughts on whether the draft door should be open or closed when the blower is on? Thanks in advance for any feed back

[maple flats]

Keep it closed. The blower will give it all it needs, better than the draft door, and if you leave the draft door open you could lose some of the blower air which could blow out the open door rather than go up to give air to the fire.

[Haynes Forest Products]

You will be making your arch air tight. I have seen some awful smokey sugar shacks from the smoke that will blow out from the smallest of cracks around pans and doors. You are pressurizing the inside of the arch and the smallest of cracks will puff out smoke.

[Wmmaple]

You will be making your arch air tight. I have seen some awful smokey sugar shacks from the smoke that will blow out from the smallest of cracks around pans and doors. You are pressurizing the inside of the arch and the smallest of cracks will puff out smoke.

Sp Haynes you would suggest leaving it open?

[maple flats]

I guess smoke escaping would depend on how good the draft is on your rig. I never had smoke escaping mine and it is not airtight. Mine has almost a 1/4" space between the feed doors and when I just had a 400+ CFM blower it did not smoke, nor does it ever with my high pressure OAF/AUF. If you get smoke, add more stack height. Mine is 19' high with my 3x8, it was also the same height back when I had a 2x6 because I have 10' walls, a steep roof and it extends at least 2' above the cupola which is only about 2.5' away..

[Haynes Forest Products]

I'm with Dave on the door being closed. Every rig will act differently and only time will tell if yours will billow out smoke. I have seen a brand new major manufacture with non air tight doors become impossible to run at high fire because of the gaps in the doors. He has plenty of stack and we slammed the doors with fire blanket in them to help get thru the season.

[Super Sapper]

You can adjust your AUF until it doesn't have any smoke escape by restricting intake. As the evaporator heats up about an hour into the boil it will also draft better. If you adjust your air you can also feed wood without shutting the air down.

[Wmmaple]

I guess smoke escaping would depend on how good the draft is on your rig. I never had smoke escaping mine and it is not airtight. Mine has almost a 1/4" space between the feed doors and when I just had a 400+ CFM blower it did not smoke, nor does it ever with my high pressure OAF/AUF. If you get smoke, add more stack height. Mine is 19' high with my 3x8, it was also the same height back when I had a 2x6 because I have 10' walls, a steep roof and it extends at least 2' above the cupola which is only about 2.5' away..

Sounds like I have a similar setup to your old 2x6 with smoke stack height. I’ll fire it next weekend for a trial run and go from there. Appreciated

[Potters3]

If using a low pressure blower (squirrel cage) put it on a dimmer switch so you can adjust the amount of air put in. I us a sharpie to mark high end, and low end (I leave blower on turned down when I add wood). After a season you will get to know where you need the switch to be at for the hottest fire. Some days will be different then others.