I built my UDS a few weeks ago and have done a couple of cooks on it. I've also used it as a kettle for a couple of cooks with great success. But I have had some trouble with temps at the beginning and could use your help. Here is what has been happening.
1. Fill the basket to the desired level and add wood chunks.
2. Light a chimney, usually about 10-12 briquettes or some leftover briquettes from a previous cook.
3. Once the chimney is going good pour the hot coals into the basket.
4. Place basket into the UDS with all 3 vents wide open as well as exhaust.
5. Once temps seem to get above 300 or so I will close one inlet. After about 5 minutes or so I'll close another and use the ball valve to do the fine tuning.
6. Temps stabilize for about 10 minutes and then start to fall. I've even had the fire go almost completely out before I realized it. At this point I open all vents and the temps start climbing again. Once they get back above 270 I try to start closing things down again. But once I get to just the ball valve only I can't keep temps steady. If I shut the ball valve and leave one nipple open my temps stay good, but a little high (275 instead of 225-250). I don't have this problem when cooking with higher temps when the nipples are wide open.
I am wondering if my ball valve is too high. Hard to see in this pic but there is an elbow just above the ball valve. It is below the exhaust but not by much. Should I get a shorter pipe and lower the ball valve or try something else first?