I purchased some 1/4 thick closed cell foam insulation with foil on one side to install in the cab of my Xpedition ADV2 Northstar. The purpose was twofold. Quiet the cab and help the ac to cool better. I installed this behind the seats and in the roof. It definitely helped the ac. Today it was 97 degrees and the ac worked great. I feel it helped on the noise as long as the rpms were 5000 or lower. Above 5000 I didn't really notice a difference. Unfortunately this machine spends a lot of time over 5000 rpm.