To insulate, install vinyl or foil-backed fiberglass duct insulation to all heating system supply ducts. ... A year of Mother Earth News magazine, backed by 50+ years of trusted DIY guidance; ...

Some studies have shown that up to 40 percent of the heat produced in a warm-air furnace can be lost through the duct system. Insulating and sealing exposed ducts that are losing heat is an easy ...

Fiberglass insulation is not airtight. Heck, it will barely even slow air propelled by convection, differential pressure or wind. It is especially helpless against air moving through a leaky pipe ...

In most pre-1975 heating systems, the plenum and ducts are made of sheet metal. The ducts are rigid, and if they have any insulation it's been taped or strapped on after they were installed.

Efficiency Improvements. In its own duct sealing campaign, Energy Star® warns homeowners with forced-air heating and cooling systems that approximately 20 to 30 percent of the air that moves through ...

Most homeowners are aware of the importance of insulation in attics, walls and floors, but they sometimes overlook other items, such as water heaters and metal furnace ducts, where insulation can ...