Good ductwork design can be the difference between consistency and inconsistency, efficiency and inefficiency in your forced-air cooling or heating system. Poor design can reduce the efficiency of your HVAC system by as much as 40 percent. Proper design requires four basic criteria.
Design
Good ductwork design takes into consideration the size and floor plan of the home as well as the loads the HVAC system will be expected to carry. Ideally, the design is completed at the same time as the house plans. Popular design configurations are named after their appearance on plans:
- Spider
- Trunk and branch
- Perimeter loop
- Radial
Installation
A good design means nothing if the installation is done poorly. Spaces designed for ducts and vents should be used for those purposes alone and not for wiring or other contractor shortcuts.
Sealing
Proper installation also includes sealing all of the connecting points (usually with mastic paste and metal screws) and ensuring there are no gaps or cracks in the ducts themselves.
Insulating
Duct insulation keeps outside heat from radiating into the ducts and diluting the cool air inside during the cooling season and heat energy from escaping the ducts during the heating season. This is important in areas of the home without conditioning, such as the attic and crawlspaces. Some contractors minimize the loss of heat energy by having the ductwork travel through conditioned parts of the home, using a drop ceiling design.
These are the basics that help you conserve energy, use your HVAC system efficiently, and keep rooms throughout your house conditioned uniformly. In an existing home, you may not be able to change the design itself, but you can work to ensure ducts are sealed and insulated. If you want a change, your best opportunity for redesign is during a home renovation or during new construction.
For additional advice about efficient heating and cooling or good ductwork design, please contact the professionals at Donald P. Dick Air Conditioning. We’ve been serving the greater Fresno area for over 40 years.
Our goal is to help educate our customers in the greater Fresno, California area about energy and home comfort issues (specific to HVAC systems). For more information about ductwork designs and other HVAC topics, download our free Home Comfort Resource guide.
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