Dense pack cellulose
Using dense packed cellulose for your wall insulation achieves two HUGE energy-efficiency-improving functions. First, it insulates your wall cavities, which dramatically reduces heat loss. Secondly, when cellulose insulation is dense-packed into your walls, it permanently tightens your home’s “air barrier.” This air-sealing technique drastically reduces air infiltration year round, further cutting energy loss. The overall impact of insulating your exterior walls with the dense pack cellulose is around a 20-30 % cut in your utility bills with non-insulated walls.
Similar to dense pack cellulose, blown fiberglass in a wall cavity makes for superior thermal coverage that you cannot always achieve with batt insulation. However it does not create as much of an air barrier as dense pack cellulose does. Advantages to blown fiberglass in a wall cavity are sound reduction, thermal efficiency, and coverage.
Fiberglass batt insulation is manufactured in different thicknesses and widths, based on common stud, joist and rafter spacing. It’s also available unfaced or faced. Batt insulation is the “traditional” or more commonly used form of insulation because of its easy to install nature, and relatively inexpensive price. Fiberglass batts can also be installed in interior walls of new construction for added comfort and sound reduction.