After the summer sun goes down, where is the hottest place in the attic?
Most people (architects, builders even engineers), quickly comment that the hottest place in the attic is up near the center of the roof. Heat rises right? Sure, heat rises but radiant travels at 186,000 miles per second in a straight line from the emitting source. For this example (since we are talking about houses), it would be the roof deck. So, if radiant heat is being emitted from the roof deck towards the insulation where does it stop? The insulation. Care to venture a guess now where the hottest spot is in the attic? The top couple of inches of the insulation! Fact is, 1″ below the insulation can be as much as 20 to 30 degrees hotter than the hottest air you can measure anywhere in the attic…including up near the peak. And it remains the hottest thing in the attic until the next morning when the sun begins its radiant heating again. It is easy to comprehend when we consider that the insulation has been absorbing radiant heat all day long, and now it is resisting that heat is t
