Low temp problem

[Guest]

Yesterday I cooked 2 butterflied chickens on the bottom rack and a rack of spares on the top. For the first 2 hours everything was going beautiful. I was maintaining a constant 232F through the top vent. I cooked using the standard method starting with a full chimney of hot briquettes (grayed) and a full chimney of briquettes on top of those. After about 2 hours though the temp started dropping to the point it finally settled in at about 217F. Nothing I could do would get the temp up to the desired 230 and I definitely couldn't raise towards the end to my desired 250-270 for the last hour or so. I eventually put another 1/2 chimney of hot coals in to raise it though.
Any ideas on why such a low temp and loss of temp with so much fuel.
BTW - It was very windy yesterday, but I did contruct the 3 sided wind break and I had a 10 minute gully washer at one point. I figure it had to be the wind causing my problems as all the fuel got used up. Everything turned out great but it took almost 8 hours to finish. Any suggestion on vent control, ie: which sides to close/open and how to orient to the wind?

 

[Rob B.]

Sounds like it probably was the wind; I know it's made things tough for me on several occasions. Even with a 3 sided shelter, you've still got wind rolling over the top and down creating a weird flow pattern.

I don't know the solution. I'm guessing the deeper the sides are, the better. And adding a top should help too. And maybe the MM is not the way to go in windy situations. Perhaps all fuel should be added already lit.