Basement Walls

There is no need to insulate the exterior walls of unheated base­ments, because there is no need for reducing heat loss. The exterior walls of heated basements (or interior walls separating heated from unheated areas) are a different matter, because heat loss is a con­cern here. An insulating layer having a thermal resistance rated at R-7 or greater should be applied. Figure 3-17 illustrates two meth­ods for insulating these walls.

Exterior opaque metal walls (Figure 3-16) should have a maximum U-value of 0.07. This will require insulation having a thermal resis­tance rated at R-11 or better, which can be provided by a layer of rigid insulation either preformed or foamed in place.

Sandwich or layered construction will vary in composition and thickness but will typically consist of three layers: two facings and a core. Exterior opaque walls of a sandwich construction should have a maximum U-value of 0.007. The thermal resistance (R­value) must be calculated on the basis of its composition and thickness.

Posted in Audel HVAC Fundamentals Volume 1 Heating Systems, Furnaces, and Boilers