Blower air distribution pipe

[MartinB]

So I finally got around to adding an air distribution pipe for my blower. These are common over on the heater meter forum. Not done yet. Still have to drill the air holes in the ring, But I thought I could include some pics. The reason for doing this is to help the charcoal basket burn evenly when using a blower instead of predominantly on one side when you introduce air in through a damper hole.. I have never had a problem with it because I had a small deflector over the hole the air came in at, which help to spread it around the bowl a little bit. But it was still obvious My charcoal was burning predominantly on the side the blower air was coming in. So why not address it? A Saturday afternoon available and $75 burning a hole in my pocket......

For some reason many people don't want to drill into their Weber bowl that's understandable. When it's a couple years old you kind of get over that hesitance.

So I put the attachment for my blower on the very bottom. Had to drill through my leg supports to do it. Not being able to drill about a 1-in hole in 1/4-in steel.... I had to drill a maximum of 5/8 and then use a carbide burr in a drill press too enlarge the hole.... It actually worked better than I thought it was going to. Did make a mess of small metal particle though. May need to reinforce those leg supports a little now. That's going to be done anyway because the pipe will be supported on a cross bar between two legs to make it a very rigid unit that won't apply any bending force to the bowl where the fitting inserts if you kick it or lift it up by it or whatever.

The reason I did it this way was so it would be easy to remove the air distributor simply by lifting up out of the tubing fitting. It can be removed and washed out to remove any ash. No, ask getting into the holes that'll be in it is not a problem typically, but some people solder there is altogether and then it would be a little more difficult. And if I didn't want to use a blower I could cap that off easily with a small tubing stub with a cap on it.

I also decided not to solder any of the tubing connections, I'm putting a screw into each of them to lock them together. Except for the one where it will lift out when I want to.

 

[MartinB]

Ash in the bottom after a 25-hour run

 

[Steve in CO]

Interesting... I wonder if adapting one of those big, flat shower head attachments would work similarly... Really great idea, though.

 

[MartinB]

Interesting... I wonder if adapting one of those big, flat shower head attachments would work similarly... Really great idea, though.

Honestly, I expect that a single pipe coming up with a deflector in front of it that spreads air out to the side would work just as well. This is probably just a more expensive way of doing it. The big thing is it does reduce the amount of air that bypasses the coals from the blower. The temperature response when the blower start to blowing is fairly immediate. In the late stages of a cook, feeding the air in a single side damper hole can sometimes result in a big temperature drop before the temperature turns around... This is because all the coals on that side have burned away and the coals that are still burning are on the other side of the smoker primarily...... At least that's my assessment. So this prevents that from happening and the overall control stays better longer

 

[MartinB]

Another big benefit, probably the biggest.... is for high temperature cooking. It is much more effective at letting the blower get the temperature up there. With the blower mounted on a single hole in the side, it struggled to maintain 350F due to the large amount of air that was bypassing the coals that also had to be heated. With the air distribution pipe, no problem at all getting the temperature up 350 ,375, 400F with much less air blowing than before. Makes it much easier to cook at the high temperature's poultry skin likes.

 

[Joe Anshien]

Did you add more vents to the top? I know the top vent on my WSM was the limiting factor on getting high temps. All I had to do was prop the top and temp went right up.

 

[Tyler]

I made one for my WSM to connect my FireBoard

Link here

 

[John K BBQ]

I like that air injector manifold idea.... pretty cool!

BBQ guru's adaptor has a little damper that sort of forces air down into the bowl... I cut a notch out of the charcoal grate so it wouldn't interfere with the air flow and that seemed to work pretty good. on my 22" WSM. Had no issues holding 225~250 for 10 to 12 hour cooks.

I'm no longer using BBQ Guru - i have a Thermoworks Billows but haven't messed with it lately. I don't think it works as well as the BBQ guru did, in part because it blows straight in the hole as described above T(W hasn't haven't provided a diverting adaptor the same way BBQ guru did). Of course, I haven't asked them to do that but I've got a few other things going and that's pretty far down on my priority list.

I also think the billows is oversized for a 22" WSM and needs some flow restriction (I bought their restrictor for use on my next cook)

 

[MartinB]

I like that air injector manifold idea.... pretty cool!

BBQ guru's adaptor has a little damper that sort of forces air down into the bowl... I cut a notch out of the charcoal grate so it wouldn't interfere with the air flow and that seemed to work pretty good. on my 22" WSM. Had no issues holding 225~250 for 10 to 12 hour cooks.

I'm no longer using BBQ Guru - i have a Thermoworks Billows but haven't messed with it lately. I don't think it works as well as the BBQ guru did, in part because it blows straight in the hole as described above T(W hasn't haven't provided a diverting adaptor the same way BBQ guru did). Of course, I haven't asked them to do that but I've got a few other things going and that's pretty far down on my priority list.

I also think the billows is oversized for a 22" WSM and needs some flow restriction (I bought their restrictor for use on my next cook)

I didn't have any problems with my side mounted design that had a simple deflector over the hole that kind of forced the air down and out to the sides. It worked really good for a long time. But it did not give as fast of temperature response as I get with this distributor. And it would not achieve as high of temperatures, because too much of that blower air was just going up instead of hitting lit coals. I can actually start this now with less coals than before, and it will get it up to 400 in 15 min if desired

 

[John K BBQ]

I can totally see your point Martin - even with a proper deflector from the normal side vent, I was never able to get much over 250 with the BBQ guru - I was using the 'undersized" battery powered Party Q which was AWESOME because it was wireless and could hold temps from 225 to 250 like nobody's business if you build the fire correctly. I only bought my T works billows because BBQ Guru stopped making the Party Q. I think they should have made a different version with on-board rechargeable batteries rather than discontinuing it...

 

[Joe T Gomez]

Ash in the bottom after a 25-hour run

Any problems with the ash plugging the vent holes during a cook

 

[Garry Milner]

I don't understand the purpose of blowers and pipes in a WSM. Can somebody fill me in?

 

[MartinB]

I don't understand the purpose of blowers and pipes in a WSM. Can somebody fill me in?

How about 25 hrs hands off?
Basically set it and forget it from 150° for bacon to 400°
No counting coals or ridiculous methods The goal is simply to be hands off.

Maybe you want to sleep all night, maybe you want to cook all day while you're at work.... And then reduce it to a holding temperature when it's done....

For me, the search for better control, started with the mud tracked in going in and out on cold rainy night to check on it and make adjustments. Wifey was not too happy about the constant muddy Prints on the kitchen floor. I was not too happy about the lack of sleep.

 

[DrAllan]

I like the idea and design, and I'm not a metallurgist but are there any concerns using copper pipe? I thought there might be some issues with using it in food setting with the high temp. I could be wrong, just something I feel like I've run across in the past. I know there are concerns over galvanized metal, and thought copper had similar issues.

Just something to consider.

 

[MartinB]

I like the idea and design, and I'm not a metallurgist but are there any concerns using copper pipe? I thought there might be some issues with using it in food setting with the high temp. I could be wrong, just something I feel like I've run across in the past. I know there are concerns over galvanized metal, and thought copper had similar issues.

Just something to consider.

I dont think so. Zinc used in galvanizing has low melting point (786 F) and sublimates. Coppers melting point is much higher...(1985 F), any way beneath the coals it actually does not get very hot.

There is however..... A drawback. And that drawback is the reduced airflow requirement. Because there's not a lot of air bypassing the coals..... It's much more efficient to heat it.... Coals last a crazy long time. But this has a downside..... And that downside is less convection , less smoke. Less bark . There is less smoke transfer to the meat. There is less crust on a brisket. The high air flow of a stick burner is why they make the best brisket bark.
Gravity feeds also give very good results for briskets.... And they have a lot of air that basically blows past The Hot zone.... Even though immensely insulated with 2" insulation, they're far less fuel efficient than my uninsulated WSM... The difference is the airflow it's using.

I think....the airflow/heat ratio on a cooker is more important to outcome than many people are thinking about. I'm working on a provision to add a limited amount of air bypassing the coals again that's controllable

 

[DrAllan]

Sounds good. I looked into it a bit and there are recommendations against food coming in direct contact with hot copper, but shouldn't be an issue with using it below the coals. I know water pipes are made from copper and some cooking pans have copper bottoms. As long as food doesn't come in direct contact with it all should be good.

A quick google and few other sites provided some info.

Good luck and have fun!