I do think the elevation plays into this. At near sea level, humidity may not be as much of an issue as it seems to be where I'm at.
I posted a rather long diatribe about some considerations when choosing the position of the sensor for your temperature controller in an oven or one of our smokers in another thread. I should just link to that rather than repost it here because I worry that I'm derailing the OP's thread with some of this. In fact, I was going to start a completely new thread with pictures and thoughts about some modifications to my particular MES, and then we could discuss a lot of these issues in that thread.
But I'll make at least one more "thread hijacking" post to this thread, and hope the OP doesn't mind. :)
Just to keep things confusing, that other thread, and the similar discussions we're having there was here:
http://www.smokingmeatforums.com/t/249454/pellets-and-humidity/20#post_1604052
Quote:
I think that if you used the MES (at least those similar to my MES40) the way the manufacturer intended, keeping the top vent closed for smoking might well be a very good idea.
Their plan is that the heating element heats the wood chips and makes them smolder intermittently, every time the heating element kicks on.
With the vent closed, very little air would enter or exit the system. So even though you're not heating by burning fuel, you'd probably end up with a fairly low oxygen environment. But that's OK because you're not counting on the chips actually burning to maintain the smoke. You're using the heating element to heat them to a high enough temperature where they decompose and emit smoke regardless. And perhaps, you even get a high quality smoke because you aren't letting them really burn due to the low oxygen!
And at the same time, because you're not allowing air to move through the smoker, you don't need as much smoke (it's got no place to go except onto your food or other surfaces in the smoker). And likewise, the heater doesn't need to work very hard, so it saves power.
But I still think people had problems with the chips not giving off enough smoke because the heater wasn't on enough of the time. So the
AMNPS and variations on it became popular.
But using them is really a lot different thing because you cannot keep them burning without some oxygen available.
Since I use the
AMNPS, I, too, keep my top vent open. I even add a section of duct to it to make it draw better, or resort to a fan to really get air moving through the unit! :)
But if I was using the system the way it was designed, I might well do better with the top vent totally closed.
Here's the main thing. I put the fan on the outside of the smoker, blowing into the intake like this:
That's the "extreme mode" where it's covering the entire inlet opening and blasting a LOT of air through the unit. That works pretty good for getting jerky to dry!
I mounted some little neodymium magnets to the corners of the fan so I can just stick it where ever I want. It really moves too much air, so I have to keep it way off to the edge of the opening. But a guy on that other thread suggested getting a variable speed fan setup and posted a link to the one he uses. It really would be great to be able to run the fan at an extremely slow speed. But just putting a baffle in front of it would block most of it, too. So there could be a lot of ways to get just the right amount of air flow.
I originally came up with this when I couldn't get my Jerky to dry in a reasonable time. The temperature I was at was 150 to 160, and it just wouldn't draw much even with the top vent all the way open, so I slapped this baby on there, and the jerky dried in a couple of hours.
But I also used it the other night to make some cold-smoked butter. I really needed something to blow the air through the unit because there was NO draft because I had the smoker turned completely off to keep the temperature low.
It actually worked too well. I think I made the pellets burn too hot and fast, and the quality of the smoke was not good. I'm thinking that you want the pellets burning cool and slow to get good TBS. When they burn too well and too hot, you get more of the creosote type smoke. Not as blue. More to the white, nasty side of things. So I should have throttled things back.
But I was going to start a thread about that whole process, too, so I don't want to clutter this thread with all of that, either.
Here's how I finally attached the little magnets to the corners of the fan:
I added some wire to the thing to give me a lot of slack between where I have the smoker and the nearest electrical outlet into which I plug the "wall wart" for it.
I took out the whole chip tray and it's associated metalwork from inside of my MES, and put some crude ductwork and deflectors inside to try to get things to work better. And I think it succeeded beyond my dreams. That's why I got the "too good" burn of the pellets this last time.
I took out all of the original metalwork and added a duct leading from the inlet past the heating element, and then aimed right at where I put the
AMNPS. There are some other heat shields and drip guards in place, too. All of it made of disposable steam-tray covers for temporary experimentation.
The idea was to get the incoming air to blow right at the
AMNPS. But then, since I was cold smoking butter, I stuck the fan partway blowing into the intake:
Those are strong little magnets, so I just let it hang down low, partway blowing into the inlet. Pardon the crude flashlight illumination used in the photo.
But even when only partially blowing into the inlet, it was still a bit too much, I fear.
Not that it went bad. I thought it was doing well. It burned about 3/4 of a row of pellets in about 3 hours. So that seemed good. But man, that butter is SMOKY!
But I also did this:
This might be kind of hard to see. But I cut each cube of butter into four smaller pieces to give them more surface area, because people said they had a hard time getting any smoke penetration into butter. I figured why not just increase the surface area to collect smoke?
Then, as if that wasn't enough, and since it was a cold smoke (no heat applied at all), I got another computer fan, that had a bracket attached to it that I'd made to blow on some hard drives in an old computer, and set it into the rack above the butter to blow down gently onto the butter, hoping to force smoke to go down into that deep pan so it wouldn't miss out on anything.
It's a 12 Volt fan, but operating off of a 5 Volt supply, so it ran nice and slow, but it really did keep the smoke stirred up and even-looking, and forced it to flow down in and around the butter pieces. Perfect!
But I think I could've used little or no augmentation of the air coming into the system and aimed at the AMNPS. It looked like a nice amount of smoke, but man, baby, that's some smoky butter!
And, I could have just given it an hour, and it might have been fine.
I took the butter out of the smoker, pressed the four pieces of each stick back together, then vacuum sealed them all as individual "sticks" of butter.
They sat in the fridge for 3 days, and then I couldn't stand it and pulled one of them out and let it get up to room temp. Then I kneaded it in the vacuum bag and really got it all mixed together really well. Then I smooshed it all against one corner, clipped off that corner of the bag, and dispensed it out into a little container as if I was using a cake frosting piping bag.
I had my wife try some, and she actually loved it! And she usually thinks I use too much smoke on everything. So I don't know.
I just think that I may have gotten too high of a burning temperature on the pellets and shifted things toward thick white smoke with that creosote flavor. But I need to let it mellow longer and try it on some different things before I pass judgement.
I guess the main point was that with a fan, you can easily have way too much of a good thing! So I need to do a better job of blocking all but just the right amount of airflow when I use a fan.
Once again, the slow fan inside was only able to be used because this was a completely cold smoke, with the heat turned all the way off.
Interesting! So you have your AMNPS right over the heating element. I can see how that would keep the pellets dry, for one thing. Induce an upward air current under the AMNPS, for another. And being on the side with the air vent, assure better oxygen to them.
On the other hand, it might lead to much faster burning of the pellets, especially when operating at higher temperatures which require the heater to be on more of the time.
You can see above how I ducted the incoming air right toward the AMNPS even through it sits over to the left. And that duct will be heated a bit by the heating element which may help to warm and dry the incoming air during hot smoking operations.
But a lesson I may have learned is this:
Although you don't want the pellets to go out. You also don't really want them burning too well, either, because they make the best tasting smoke when they're on that verge of going out.
I read a Wikipedia article about smoking, and it said that if the combustion temperature of the smoking wood is too high, it will make the good tasting stuff, but then the high temperatures will break those molecules down into bad-tasting stuff. So you really want your smoke generator to burn the wood at a low temperature. And to that end, my fan blowing into the duct aimed right at the AMNPS may have been going too darned far!
I really would like to experiment with combustion conditions and see if I can control things so the pellets don't go out, but also produce only good-tasting smoke.
I think we may need continuous infra-red temperature measurement and a controller to operate a damper or fan to keep the pellets burning, but just not too darned well! ;)
More of the "modify everything" philosophy at work!