Q's Daily DIY Green Tips: Tight Ductwork

A great way to improve the energy efficiency of any forced air heating and cooling system is to tighten up the duct work.  Duct tape which will hold a duct seam together is not the tightest sealant.  In accessible areas, apply mastic to reduce air leakage.  This will increase the efficiency of your system by delivering more conditioned air to living spaces.

P Quentin Unsworth