Proper heat distribution

Bytor

Well-known member
Messages
535
Location
Knoxville, TN
Grill(s) owned
  1. Trailblazer
So, I made some burgers on the smoker this evening. I made 6 burgers from 82/20 that were 4 oz and about 3-1/2" each. I had the smoker set to 500 and placed the patties on the grill. After 4 minutes I checked them and the two on the right side were well cooked and were set. The two on the left side were still pretty raw and had not set. I proceeded to play musical chairs with the patties for the remaining 10 minutes or so trying to get them to cook even. By far any patty on the right side cooked the quickest and the smoker was smoking alot.

I put a piece of wide aluminium foil on the grease pan to easier cleaning. Maybe, the foil wasn't pressed down smooth enough to assist in the grease flow and maybe impeeded in air circulation within the unit? The attached photo isn't the greatest, however things ended up late and the weather was supposed to get nasty, so I didn't want this sitting around in the smoker for a day or so. Things seemed to get really charred. Plus, based on the attached photo, it doesn't look like there's even heat flow with the aluminium foil and associated charring of it.

Based on the photo, and description, is this normal, or maybe did the foil interfere some with air movement? It was putting out a ton of smoke, which makes me think that the foil was blocking the grease flow. I did have some grease pour out into the drip pan, though it seems like most of it was left on the foil/drip tray.

Any ideas would be appreciated.

Thanks
Heat flow.jpg
 
@Bytor the first thing I notice in your picture is your aluminum foil comes up and over the side wall of your drip pan - loosely at that. This will indeed affect airflow.

If you're going to use foil. I would suggest you go up the side wall but do NOT go over the wall. So make a "U" out of the foil. You also want to make sure the foil is laying as flat as possible. No tall peaks or hills.

Finally, of course make sure your grill is sitting on level ground. Otherwise if it's sitting "up hill" on the right side that will also slow or stop the gravity effect of the drip pan.
 
Reminder that RecTec speaks specifically about foil disrupting heat... Beyond that, there will always be some variation... if you're particularly particular like I am, map it out with a Fireboard.
 
Thanks for the comments. The patio is flat, so I'm thinking the issue was with the foil. I will be more careful the next time. Is the use of foil standard practice for the dup tray? Seems that if not used, the drippings would just burn and make a mess for cleaning.
 
@Bytor the topic of using foil vs not is like Ford vs Chevy.

For the first several months I used to foil my drip pan as well. The last dozen or so cooks I haven't and instead simply use a putty knife to clean it off. Both methods are quick and easy for me.
 
An update to my original post.

I set the temp to 225. I placed the probe of my Thermoworks DOT right next to the internal probe. After 20 minutes, the stock reading was 225 and the DOT was 223. Over the course of 10 minutes, the stock reading held at 223-225, whereas the DOT ranged from 210-268. Not once did the stock display deviate that much. I guess if you averaged it out, maybe the stock was close to average temp. Either way, the stock read pretty good. The DOT was verified to be +/- 2 degree F upon testing.

I then moved the DOT probe to the right side of the grill, on the center grate and placed inbetween the 4-5 rung of the right side of the grate (sorry, no photos..). For the course of 1.5 hours, the temp of the DOT held close to the 270-280 mark. I had a 5# rib roast going on at the same time, but don't think that would have any impact on temp. I did have foil on the drip pan, but there was no overhang of it and it was applied very tigh, as to not impeed any air flow.

Is this a normal thing for Trailblazer units?
 
An update to my original post.

I set the temp to 225. I placed the probe of my Thermoworks DOT right next to the internal probe. After 20 minutes, the stock reading was 225 and the DOT was 223. Over the course of 10 minutes, the stock reading held at 223-225, whereas the DOT ranged from 210-268. Not once did the stock display deviate that much. I guess if you averaged it out, maybe the stock was close to average temp. Either way, the stock read pretty good. The DOT was verified to be +/- 2 degree F upon testing.

I then moved the DOT probe to the right side of the grill, on the center grate and placed inbetween the 4-5 rung of the right side of the grate (sorry, no photos..). For the course of 1.5 hours, the temp of the DOT held close to the 270-280 mark. I had a 5# rib roast going on at the same time, but don't think that would have any impact on temp. I did have foil on the drip pan, but there was no overhang of it and it was applied very tigh, as to not impeed any air flow.

Is this a normal thing for Trailblazer units?
Well, did you leave the heat shield hanging over the heating element? Or did you purchase the searing grates? This is a smoker so that looks like the base grill grate unit and the metal isn’t designed to retain high temperatures. Also removing the heat sheild and removing the grease pan if you have the searing kit you need to turn the nob to max than wait like 20-30 minutes and sear your meat. Otherwise the grill without those extensions is only good for smoking meat, not grilling or searing In the traditional sense.
 
I kept everything as is. I typically keep it it at 225-250 for smoking and 375 for chicken. I have other equipment for searing that will get the job done.
 
I will tell you that my RT-590 consistently measures hotter at the grate level than what the built-in probe measures by about 10 degrees over the couple of cooks I've tested. And, the right side of the grate surface is always hotter than the left side - anywhere from 15-30 degrees hotter over the course of a longer cook. All the while the stock measuring probe that is on the left sticking up halfway keeps dead on the temperature I set.
 
What I've found matches your results. At smoking temps of ~225 the temps across the grate are close but still hot on the right side. The difference climbs as the temperature increases. I'm no scientist but let me suggest having the fan blowing through the pellets on the left side to the right side creates this difference. The hotter the temps the more airflow and thus a bigger temp difference.

I'm adjusting my cooking by putting the thickest parts on the right side or turning every 1/2 hour to keep things even. Here is a duck I did at 325 while checking the temps across the grill.
IMG_0457.jpeg
 
I'm no scientist but let me suggest having the fan blowing through the pellets on the left side to the right side creates this difference.

I expect it’s probably something other than the direction of the air from the fan. The Bull’s fan blows from the rear of the grill to the center, and my experience is that it too is hotter on the right side. It’s not a big enough difference for me to be concerned-I just face the meatier cut of the meat to the right and/or rotate the meat 180 degrees in the middle if of the cook (which I often do when cooking in my house oven).
 
What I've found matches your results. At smoking temps of ~225 the temps across the grate are close but still hot on the right side. The difference climbs as the temperature increases. I'm no scientist but let me suggest having the fan blowing through the pellets on the left side to the right side creates this difference. The hotter the temps the more airflow and thus a bigger temp difference.

I'm adjusting my cooking by putting the thickest parts on the right side or turning every 1/2 hour to keep things even. Here is a duck I did at 325 while checking the temps across the grill.
View attachment 8369
Holy moly your dinner looks like a patent in a hospital with all those probes connected. ;)
 
I noticed the same, right side hotter, built in probe does not show the temp variations that an aftermarket thermometer does. I only use the RT for low and slow so it's fine for me. I do turn 180 at about the half way point.
 
Yeah, I usually rotate along the way too. I'm going to try to make a baffle out of foil and place it on the right side of the heat shield to see if limiting some air flow to the right side might help any. I swear I did this before, but don't think I ever got around to it.
 

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