Optimal duct design isn’t an afterthought to the master plan of an energy-efficient home; it’s an integral part of it. Today, considerations about ductwork are included in the earliest planning and layout of new home construction. Manual D software allows your technician to design ductwork to the specific heating and cooling load of the home and match it to the output of your HVAC equipment.
Produced by the Air Conditioning Contractors of America (ACCA), Manual D is now part of every professional contractor’s resources. In addition to the scientific formulas, optimal duct design follows several fundamental principles that should be elements of any home built for an energy-efficient age: Short, straight spans of supply ducts are most efficient. Lengthy segments with complex curves and joints subject air flow to excessive friction as it travels through the ducts, diminishing system performance and increasing potential air leaks.
Design ducts into conditioned zones that are heated and cooled like the rest of the residence. Ductwork routed through unconditioned zones such as attics or crawl spaces is subject to acute temperatures and substantial thermal loss. Where installing ductwork in unconditioned areas is unavoidable, ducts should be insulated to U.S. Department of Energy standards. A return duct for every supply duct is preferred.
To maintain proper air balance in rooms, supply air should leave the room through its dedicated return. Where this is not feasible, a clear air path to a central return should be provided through grilles installed indoors or jumper ducts routed through ceilings. Wall cavities are not substituted ducts. Utilizing the voids inside walls or between ceiling joists as return ducts instead of proper metal ductwork is a false economy. Air leakage from these spaces is substantial and will result in major energy loss over time, as well as potentially contaminated indoor air quality.
The plumbing, heating, and cooling source for northern New Jersey residents since 1988, Pipe Works Services Inc. are ready to assist with all your home comfort needs. Contact us for more information about the importance of optimal duct design when upgrading your home HVAC system. Our goal is to help educate our customers in Chatham, NJ, and surrounding areas about energy and home comfort issues (specific to HVAC systems).