DIY

In new home construction or in retrofits, proper duct system design is critical. In recent years, energy-saving designs have sought to include ducts and heating systems in the conditioned space.

Efficient and well-designed duct systems distribute air properly throughout your home without leaking to keep all rooms at a comfortable temperature. The system should provide a balanced air supply and return flow to maintain a neutral pressure within the home.

Even well sealed and insulated ducts can leak and lose or gain some heat, so many new energy-efficient homes place the duct system within the conditioned space of the home. The simplest way to accomplish this is to seal the attic space with foam, under the roof deck or to hide the ducts in dropped ceilings and floor spaces within the conditioned space of the building envelope. In both of these latter cases, care must be taken during construction or retrofit to ensure proper air barriers are in place, preventing contractors from using the duct chases for wiring or other utilities.

Check your ducts for air leaks. First, look for sections that should be joined but have separated and then look for obvious holes.

Duct mastic is the preferred material for sealing ductwork seams and joints. It is more durable than any available tape and generally easier for a do-it-yourself installation. Its only drawback is that it will not bridge gaps over ¼ inch. Such gaps must be first bridged with web-type drywall tape or a good quality heat approved tape.

If you use tape to seal your ducts, avoid cloth-backed, rubber adhesive duct tape — it tends to fail quickly. Instead, use mastic, butyl tape, foil tape, or other heat-approved tapes. Look for tape with the Underwriters Laboratories (UL) logo.

Hire a Licensed HVAC professional to install both supply and return registers in the living area.

Be sure a well-sealed vapor barrier exists on the outside of the insulation on cooling ducts to prevent moisture condensation.

If you have a fuel-burning furnace, stove, or other appliance or an attached garage, install a carbon monoxide (CO) monitor to alert you to harmful CO levels.

Be sure to get professional help when doing ductwork. A qualified professional should always perform changes and repairs to a duct system.