In Michigan, 60 % of the homes energy use is from heating. Heating losses occur through air leakage (convective energy flow) and insufficient or ineffective insulation (conductive energy flow)
The most cost-effective energy improvement for most homes is locating and sealing the numerous areas of air leakage into the building
Sealing air leaks to tighten the building shell has benefits beyond the obvious, such as the reduction of uncomfortable drafts and saving on utiltiy bills. It also makes your existing insulation do the job it is supposed to do.
Insulation is tested in the lab to be R-13 or R-19 and so on with no air flowing through it. Fiberglass with air flowing through it is also called “filter-glass” because of the dark streaks of dust collected from the air.
Sealing air leaks creates the air barrier that most insulation needs in order for it to perform as intended.