5 Principles of Ductwork Design That Impact Your Comfort

If you’re replacing your HVAC system, renovating your home or building a new home, ductwork design is one feature of your project that should receive careful attention. Good ductwork design is essential for getting the most out of your HVAC system and providing good indoor air quality. These principles can help guide you and your HVAC contractor toward greater efficiency and comfort.

Duct Locations

Routing ducts through attics, crawl spaces or exterior walls exposes them to temperature extremes, where heat gain or loss will diminish their efficiency. If you must put ductwork in unconditioned spaces, be sure the areas are well insulated, as well as the ducts.

Proper Sizing

Your heating and cooling consultant should size your HVAC equipment with Manual J software, and then use Manual D software to determine duct size. Although square- and rectangular-shaped ductwork have their uses, round ductwork is generally the most efficient.

Proper Materials

Most ductwork is made of galvanized steel or fiberglass. Aluminum, copper and other materials are also sometimes used. Metal screws, mastic and metal tape should be used for fastening sections together.

Balanced Airflow

Ductwork design should incorporate balanced return and supply airflow to prevent negative or positive pressure from developing within the home. Unequal pressure can result in uneven temperatures and back drafting of combustible gases from the furnace. Ideally there should be return and supply vents in each room, but if there’s only one central return, it should always be unobstructed. Balancing can be achieved in rooms without returns by installing grilles in doors or jumper ducts in ceilings to pass air back to the central return.

Good Design

Some basic principles for good ductwork design including the following points.

• Shorter duct runs are better for minimizing heat loss and gain.
• The best designs incorporate a minimal number of turns.
• The design of the home and the climate determine which type design is best. Some common ductwork configurations are trunk and branch, spider, perimeter loop and radial

Learn more about ductwork design from the pros at Tempco Heating and Air Conditioning, or contact us today at (847) 670-7000.