Yeah, the intuition of wanting air in the cavity is a correct one. it's just that what we actually want is a vacuum. This creates a thermal gap a d is why cups with vaccum keep shit warm/cold awesomely. We cant, realisticly achieve this so instead we shove shit into the walls to protect or little air gap from being tampered with. Fiber glass works OK, but foams work better.
Yeah, the intuition of wanting air in the cavity is a correct one. it's just that what we actually want is a vacuum. This creates a thermal gap a d is why cups with vaccum keep shit warm/cold awesomely. We cant, realisticly achieve this so instead we shove shit into the walls to protect or little air gap from being tampered with. Fiber glass works OK, but foams work better.