Sorry I didn't get back to this thread earlier!
I've done some smoking since making my modifications, and everything has worked well. I haven't used the fan to force air through the last few times as it wasn't needed. But it was rainy and cool for the last two, and still, I had good burning of the pellets.
I posted better pictures and explanations of everything in this thread:
http://www.smokingmeatforums.com/t/249454/pellets-and-humidity/20#post_1606361
There's a lot to all of this, and with all of the different models and types of smokers people have, it can get confusing to visualize what's happening in smokers with which we're not really familiar!
But the general concepts are still very useful to everyone, I think! So it's neat to see and read about what everyone is trying out, and how it's working for them.
One point I will make is that I am reluctant to use anything but a purpose-built draft inducer or convection oven fan at the outlet of (or inside) one of these smokers because of the high temperatures and smoke that will be present. That's why I've been using the fan only to force cool, clean air into the smoker during high-temperature operation. The exception is the small fan running very slow that I have put inside the smoker to circulate the smoke better during cold smokes. And I just accept that the fan will probably fail prematurely due to build-up of smoke residue. Hey. They're cheap! :)
But of course, the same argument could be made for using on on the vent to suck out the hot, smoky air. As long as it doesn't go up in flames, you're really not out that much if it dies prematurely, I guess! But the cabinet on mine is pretty tight. The door seal works well. I don't see smoke leaking out anywhere when I "pressure it up" with the fan blowing into the inlet.
You really have to beware what you're seeing for temperature readings on different thermometers in different places in smokers and ovens. It really can vary a lot. Especially if there's no active stirring of the air in the chamber. None of these home smokers seem to employ any sort of active stirring of the air, but the makers of the commercial units are very aware of this. Not only is the smoke not evenly distributed, but the heat isn't, either, unless you have a blower of some sort mixing things up.
And this makes good temperature control quite difficult.
I'm seriously looking at various draft inducers and fans meant for "convection ovens" to use in my smoker. I do think that's the only real way to ever get even heating and smoke throughout the cabinet.
But having said that, I wouldn't expect such large swings in temperature between when the heating element switches on and switches off. Looking only at the display on the controller, I'd be curious as to what sort of temperature "hysteresis" it employs. On mine, it's not a ridiculous amount. I need to check. But we have to remember that one of the design considerations on these MESs is that they're trying to burn the chips in the drawer above the heating element in the original design. So they probably set things up to have a fairly large amount of hysteresis so that when the heater comes on, it stays on for quite a while so it can ignite the chips. If it cycles on and off too quickly, that will give tighter temperature control, but will also never let the heating element get hot enough to burn the chips at all once the smoker comes up to temperature.
It's also possible that they do more than just employ a rather large amount of temperature hysteresis. They may well have a timing function built into the controller to assure some minimum on-time for the heater any time it does come on. That way, they get some chip burning, for sure, every so often. I have NOT tested this or carefully observed the behavior. I'm just speculating on why we observe some of what we see with these units. There may be method to their madness. It just doesn't perfectly suit us users of different smoke generators!
So we are paying something of a price for their original design. For those of us using a different way of generating the smoke, we would prefer tighter temperature control. But that's not the way these units were designed. So without putting in our own custom temperature control, we're stuck with more hysteresis than what we might program if it was up to us now that we're using AMNPSs, and the like.
Quote:
OK. Cool. Take a look at the thread I linked to at the top of this post for better photos showing what's really going on in mine. I am having excellent luck with it. It's ugly, and needs to be done in a more permanent and professional way, but for a "test kludge", it's performing well for me so far.
I've seen those on TV every Thanksgiving time, but never tried one. I'm not sure I'd like it, but it is pretty amusing!