Originally Posted by Catt22
Go to a group brew sometime. It always amazes me to see that there are very seldom two systems set up exactly the same way. That's part of what makes this stuff so much fun.
And makes it so confusing to new people!
I've experienced the "deer in headlight" syndrome several times at our club brew days.
The times I did brew in the bag drew the new people like moths to a flame because it looked so familiar to them.
To stay on topic, I agree that the issue with heat loss is going to be mostly from the top of the keg and any exposed metal.