20-40% of the energy used to run HVAC systems is wasted due to air leakage. Unconditioned air enters into the home and conditioned air escapes from the home through every hole, gap and crack. Door frames, window frames, electrical outlets and switches, recessed lights, plumbing penetrations, attic hatches, chimneys, vents and flues are common locations for air leakage. 31% of infiltration occurs through openings in walls, ceilings and floors.
In addition, the ductwork that conveys heated or cooled air to all parts of the house often contributes significantly to air leakage. If not properly sealed, the joints where lengths of ductwork come together, allow heated or cooled air to escape before reaching the registers in your living space. Conversely, leaks in ducts can draw unconditioned air into the system making heating and cooling equipment work harder and longer to maintain desired temperatures. The result is unnecessary energy consumption and needless expense. Leaky ducts are responsible for about 15% of air leakage in most homes.