Considering an Addition? Give Some Thought to Ductwork Design Before You Break GroundProfessional ductwork design is the keystone for channeling maximum performance from heating, cooling, zoning, whole-house humidification systems and more. If you’re planning a new addition, retrofit or new construction, plan early and choose a reputable company with the mechanical know-how and designing experience to do the job right.Ductwork design components

The primary components of good ductwork design are correct sizing, balanced airflow, utilizing the shortest routes within conditioned spaces and impermeable sealing.

Manual J from the Air Conditioning Contractors of America should be used to calculate a home’s heating and cooling load. These results are needed to accurately size the new duct system using Manual D and to accurately size the new heating and cooling system, if applicable, using Manual S.

Installing ductwork in conditioned spaces is paramount for maximizing energy efficiency. Ducts located outside of living spaces, such as an attic or basement, lose too much heat energy through thin duct walls. Insulation helps, but it’s better to utilize sealed chases, raised floors and hang ceilings.

Contrary to its popular name, silver duct tape should not be used to seal ductwork. Sheet-metal screws, mastic sealant and butyl tape are time-tested industry standards to ensure long-term integrity of duct connections.

Ductwork design layout

Two common ductwork design schemes are the trunk and branch system and the radial system. Both ductwork systems are conducive and adaptable for installation in conditioned spaces.

  • Trunk and branch is a common design for many homes. A large primary trunk duct connects to the supply plenum of the air handler. Smaller run-outs, or branches, extend from the trunk to the supply outlets. Trunk and branch systems promote balanced airflow for maximum comfort and energy efficiency.
  • Radial systems utilize duct runs that extend directly from the supply plenum, much like the spokes of a wheel extend from the hub. The radial design generally uses shorter duct runs, which helps maximize airflow. Radial systems are well-suited for modification, such as parallel duct runs, to best fit complex home designs or new additions.

For the very best in expert ductwork design in the Phoenix Valley, contact Wolff Mechanical today.

Our goal is to help educate our customers in the Phoenix Valley area of Arizona about energy and home comfort issues (specific to HVAC systems). 

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