*(all) set. (to do something) prepared or ready to do something. (*Typically: be ~; get ~.) Are you set to cook the steaks? Yes, the fire is ready, and I'm all set to start.
How long will the odor last from our newly installed cellulose insulation? The odor is kinda of like a mild ammonia smell and is only noticeable when we're running the a/c.
Still air is just about the best insulator there is. At the molecular level, heat transfer is easier when atoms are packed closely together. So the actual point of most insulations is to get rid of as much solid material and trap still air inside little pockets. Most closed cell foams trap different gases than the air we breathe, but they still work on the same principle, replace as much solid material with gas as possible. But air is also a fluid, and as such large volumes of air are great at convecting heat. If you have a large air current, it will transfer heat from hot to cold pretty effectively.