UDS Temp will not drop

[jlafrenz]

I was smoking a pork loin today for fathers day. Everything was going great until I put in the meat thermometer. Shortly after I did this, the temps started to increase rapidly. I closed all the vents and this didn't really help. I pulled the lid and let some of the heat out, but the smoker is still staying steady at 275 or so. The vents have been closed for 45 and the temp has not really dropped much. Normally my UDS is very responsive to my valve adjustments for air flow. The last few smokes that I have done, as soon as I close all the valves the temps drop like a rock. Not today. This is the first time that I have cooked mid day as I usually start in the evening and finish up as the sun goes down. My guess is that having the smoker in direct sun at this time of day is adding to the increase in temps. Is this correct? Or did I maybe have too much wood? I am using lump charcoal, but I have for all my other smokes too. How can I remedy this for the future?

 

[ecto1]

Sounds to me like you had your lid open for just a little too long. When you opened that lid all that oxygen rushed in causing the spike. I find lump gets hotter faster. I tell everyone with UDS smokers that it is a lot easier to raise your temp theitn it is to lower it.

 

[jlafrenz]

I thought this might be the case, but wasn't sure. I have previously smoked wings and had the lid off to flip them without issue. I already have the temps up around the 300 mark though so I may just not have noticed it.

I actually just went to check the smoker and it is still at 225 and burning. I closed all the vents roughly 5 hours ago. I guess some might view this as a good thing that it holds temps for so long, but it seems really odd that it is still going with everything sealed up. I view it as an issue because I want to stop burning fuel and be able to put it back in the garage. I am now guessing that air might be leaking in around my intakes. Best thing I can think of is to get some high temp silicone and go around the edges of all my intakes and grill holders.
 

 

[banjo]

One other thing I've come across - as Ecto1 said, opening it up and letting air get in will cause a spike.  Once this happens, and the fire gets hot, it's pushing a lot of hot air out the exhaust - and that can be creating enough low pressure inside the smoker so that fresh air is now getting pulled in....which pushes more hot air out, and more low pressure, and more air seeping in.  You may not have gotten the fire hot enough in the past to experience this, and maybe today you did get it hot enough.

So, make sure all of your various connection points are tightly sealed, so no air can get pulled in on lower than normal pressure.

As Ecto1 said, it's harder to get the heat out once it's built up.

 

[jlafrenz]

All that makes sense. I was just amazed that the fire burned for so long at a steady temp after I had closed all the intakes. Even when I run them wide open to make wings, I can shut them all and it will drop like a rock and be cool in under an hour. I will head to the store to pick up some high temp silicone to seal around my intakes.

In the future when I have to pull the lid off like this again, what is the best thing to do with the intakes? Do I close them to avoid a rush of air in or keep them open to avoid the pressure system mentioned?

 

[banjo]

I would close them prior to opening the lid, but just before.  

If you starve a really hot fire suddenly for oxygen by shutting everything down and then you open the lid, the inrush of oxygen can cause a flash.  I've experienced this on a Big Green Egg.  The clue on this is that it was really hot to begin with, retaining that heat and then opening up letting the oxygen get in where it's already hot enough to ignite.

And, be quick about it - try to avoid having it open any longer than necessary.

The fact, per your comment "...[color= rgb(24, 24, 24)]amazed that the fire burned for so long at a steady temp after I had closed all the intakes" definitely indicates you have air leaks where air is being drawn in to the combustion area.[/color]

 

[jlafrenz]

Thanks Banjo. I plan on sealing it up tomorrow and then trying my first pork butt on Sunday. If I need to open the lid for any reason, I will be sure to have an extra set of hands around to help and make things quick.