The U.S. Department of Energy’s (DOE) Building America1 Industrialized Housing Partnership (BAIHP) has collaborated with two of its industry partners to work on a portion of the project that relates to the construction and evaluation of prototype interior duct systems. In 2006, work began on a duct system design that would locate the entire length of duct work within the air and thermal barriers of the envelope. One of these designs incorporated a high-side supply register that connects to the conventional floor duct. The other design utilized a single soffit located within the conditioned space at the marriage line.
The Florida Solar Energy Center’s (FSEC) Manufactured Housing Lab (MHLab) was retrofitted with an interior soffit duct. The duct system was added on so that either the attic duct system or the new interior duct system would be able to supply air to the conditioned space using the same mechanical equipment.
The initial results of this work show approximately a 10% to 20% heating/cooling savings when compared to conventional attic duct work construction techniques and nearly 7% savings when compared to a conventional in-floor system
