PORTLAND, Ore., Aug. 31, 2011 /PRNewswire-USNewswire/ -- Earth Advantage Institute and the Northwest Energy Efficiency Alliance have produced a series of case studies that illustrate successful implementation of the "Ducts Inside" strategy, where the air handler and all ductwork are located inside the conditioned space of a new home. This practice can reduce home energy use by 15-20 percent compared to typical HVAC installations. The studies are designed to inform designers, architects, builders and subcontractors about the benefits and challenges of best practices for building with ducts inside. The case studies were selected to represent diversity in the residential marketplace, including urban infill, suburban, one-story, two-story, custom, speculative, and production-built homes. These Northwest builders, located in either marine or cold climates, are certifying their homes to one or more green certification standards: ENERGY STAR®, Earth Advantage®, LEED® for Homes, BuiltGreen®, or NAHBGreen®. Builders reported a number of strategies for success, including mapping duct layout on plans and bringing subcontractors into the process early for improved collaboration. Subcontractors appreciated being pulled in and were able to help determine how to use materials efficiently and avoid installation conflicts with other tradespeople. Additional strategies included marking locations of all ducts, boots, and electrical and plumbing locations to ensure smooth installation; using shorter depth beams to provide needed space for ducts to pass underneath; and using insulated flex duct to provide protection to the ductwork running through open web floor trusses. Challenges included educating builders, home inspectors and new homeowners who were often skeptical that "right-sized" systems with supply registers located on the interior walls would meet the load and satisfy comfort needs. Pre-designed homes with such features as varying ceiling heights and vaults can make the process more time-consuming. The builders indicated that their customers were receptive to the "ducts inside" concept. One buyer was surprised that the strategy was not already the norm. The HVAC contractor interviewed said that offering systems with ducts inside has opened up new markets for his company. The case studies can be found at www.ductsinside.org.
