Housing Insulation

Prevention of direct heat flow through a wall or ceiling is not the only reason for installing proper insulation. Three other reasons, according to residential housing expert Axel R. Carlson, are to prevent condensation, to reduce convection drafts within a room, and to avoid cool surfaces for a person's body heat to radiate to.

Whereas some rooms feel warm and comfortable, others definitely feel cold. Chances are the room that feels cold has cold walls and a cold floor. Such a room has convection drafts of cold air down the walls and across the floor. Furthermore, every object in a room radiates energy to every other, and the net amount of energy exchanged depends upon the temperature differences between the objects. Even across the room, a cold wall feels cold to a person's warm face because the face loses energy to the wall by radiation.

A truly serious problem is that cool interior surfaces of buildings cause condensation. If there is not a perfect vapor barrier, the condensation enters the floor, wall or ceiling where it can reduce the insulating value of material in the structure and can form ice. Water stains and other damage can occur when the ice melts.

How critical the vapor barrier is was learned well by some of us several years ago. For free we got a military surplus walk-in freezer which we figured would make a perfect auroral observatory. Nobody thought about the fact that on a freezer the vapor barrier is built onto the exterior of the structure instead of the interior. The first cold snap that winter filled the walls with ice. Since when we walked in we froze, we knew for sure that we had a walk-in freezer and not an auroral observatory.