New Heater Meter is online! Advice for offset smoker?

Hi There, I powered up my HeaterMeter and RD3 for the first time and everything looks to be working great from the start! :::relief::: So now I have to fabricate a baffle and attachment plate for an Oklahoma Joe's offset smokers. Its a pretty stout one... it weighs a ton.

Does anyone have any advice for using an offset? The smoker was a Christmas present, so I have only used it a couple time so far. I plan to seal the firebox well with Hi temp silicone. Also plan to fabricate a metal plate to place inside the damper, and that is where the RD3 fitting will go.

Get some tuning plates for that smoker, if you don't already have some.

Read up on them -- they are invaluable to owners of standard offsets. As far as the HM itself -- you might do some searching here to see if anyone has some better-than-default settings for offsets (depending on size and fan output).

Good luck and let us know how it goes.

Thanks I'll let you know how it goes!

Some pics of the grill and fire box, particularly the area where you plan to connect the RD would be helpful, or a link to the website with such pictures. I just did a search and found lots of places selling them, and links about mods etc, but not knowing exactly what you have it doesn't make much sense for me to search and speculate.

I don't have an offset smoker (YET) but from helping others in the forum one thing I learned is you need to make sure the air you feed the fire is effective. Meaning, you want the air that enters the fire box to hit and stoke the fire rather than passing over it and going straight into the grill. If your air is coming in low (below the fire) then you may be ok, but if it comes in higher then you might want to use some sort of angled pipe to shoot the air downward, or perhaps use an "air burner" design?

Insulated grills like kamado's hold heat so well that they require smaller fires and lower air flow, so they do just fine without being too fussy about where the air from the HM goes. However, with grills that bleed heat like bullet smokers, UDS, Offset smokers etc it is more important WHERE you put the air because as they leak heat the HM will stoke the fire... So you have the HM forcing more air through the pit... You can easily end up with a scenario where you are forcing your hot air out and replacing it with cold air making the pit temp drop. In reaction to this your HM pumps in more cold air, the fire stokes up really high to compensate but when the HM drops the air flow down as it approaches the setpoint the large fire will be sending you into overshoot... So you get a rocky pit temp with high air flow that can dry out food, and periods of choking off the pit from overshoot where the more bitter smoke can get produced and held around your food, and in the process you will burn excess fuel to boot. So with these grills you want to try to get as many BTU's out of your air flow as possible to limit the above factors. If your inlet shoots at the fire you are probably good, if it's up high aim it down at the fire. Or try an air burner design...

An "air burner" is just a set of pipes under your coal basket that has small air holes drilled into it (kinda like a gas burner, hence the name). You connect the HM output to the pipe system and as it blows little jets of air come out of the holes and really stoke the fire good, it makes very efficient use of the air you push into the pit. So less air in, less cooling of the pit, faster stoking of the fire... Happy Heater Meter!

High air flow from your HM is really the enemy you will be fighting against, the colder the ambient temperature the harder the battle. It might help to get to know the pit with a couple conventional (non HM) cooks. Use the vents to achieve a low and slow and then feel the output flow from the exhaust stack. Then when you have your Heater Meter rig set up compare the output flow to see if your air volume is way high or in a similar ballpark.

Interesting that gives me a lot to think about.

With regards to the firebox, its a cylinder on its side of course, and I have a cubicle coal basket - flat on the bottom, so that would leave a perfect space under it to pipe in an air burner. As far as the damper goes, if you're looking at the end of the firebox, the damper is a sliding piece that covers from 5 o'clock to 7 o'clock kinda thing. If I took the approach of covering that piece with a piece of metal I would think you could drill a hole in that that would jet directly into the middle or lower side of the coal basket. I do like the idea of the air burner though. I could probably set the max fan down to 50% and make it very efficient and focused.

If I did an air burner, what kind of pipe to use?

Interesting that gives me a lot to think about.

With regards to the firebox, its a cylinder on its side of course, and I have a cubicle coal basket - flat on the bottom, so that would leave a perfect space under it to pipe in an air burner. As far as the damper goes, if you're looking at the end of the firebox, the damper is a sliding pie wedge that covers from 5 o'clock to 7 o'clock. If I took the approach of substituting that piece with a plate of metal I would think you could drill a hole in that that would jet directly into the middle or lower side of the coal basket.

I do like the idea of the air burner though. I could probably set the max fan down to 50% and make it very efficient and focused.

If I did an air burner, what kind of pipe should I use?

That is a pretty common setup for the vent, and I think you are right with the basic approach. Fabricate a metal plate to cover that opening and mount the RD to it with a conduit connector or whatever. IDK about the heat factor there, if the metal tube gets TOO hot you might need to extend the pipe outside the grill a little distance to allow the heat to dissipate a bit. The RD is ABS plastic and it will start to soften up at about 90C and will melt starting around 180C.

On the air burner, I used copper water pipe on mine because it is easy to manipulate and wont rust, but other types of pipe should work too... you obviously don't want anything painted or coated with anything. It's just a tube for air to flow through that can take the heat of your fire.

Is blackpipe OK for the air burner? I would get it really hot first and burn off all the crap...

You know, good question... I am not an expert in metallurgy or anything so IDK. It would certainly be sturdy enough but IDK what the black stuff is and whether it would be healthy to heat it.

Hmm... looking it up, apparently its just plain old steel. I'm not sure it has a coating apart of oil to keep it from rusting.

Any advice on hole size for air burners?

Start with fewer/smaller holes and test it out, then move up to bigger/more holes if you are not able to achieve the temps you are looking for. If you are running a servo damper the size of the holes is less important, as the damper will choke down the air flow if you have overshoot, but if you are not running a servo damper then you want to make sure the holes are small because too many/too big holes could allow too much convection current. I would start out around 1/8" on the holes.