Engineer's Notebook: Return Air Systems

The benefits of using architectural plenums for return airare substantial, including much lower first costs and lower energy costs. Inmost cases, the design is also easy: just ensure that each space has a lowpressure return air path back to the air handler. But where there are many fullheight walls and other constrictions, care must be taken to ensure that the lowvelocity return air path is maintained by properly sizing transfer ducts andsound boots.