Floor Trusses Hvac Chase

Most truss manufacturers can produce custom plenum trusses that include an integral duct chase.

Floor trusses hvac chase. Open web design leaves plenty of room for mechanical systems hvac plumbing electrical to be installed within the floor frame. Floor trusses can span farther between bearing points than i joists allowing for larger open rooms. Still commonly used is the panned floor joist. The resulting chase is variously called a raised hvac coffer and an inverted soffit.

Recently i discovered that the truss system would not support metal ducts. Open joist is a revolutionary open web all wood floor truss engineered with superior strength and load carrying capabilities. Floor trusses go by many names and since parallel chord 4x trusses can be used in roof systems the term floor truss is not necessarily the most accurate term although it is the one in most common use. Ducts in a special roof truss.

Hvac chases or duct runs may be designed into floor trusses to allow for plumbing and or heating and air conditioning ducts to be installed in the floor. Design criteria for the 4 x 2 floor system. Are there charts illustrating allowable hvac duct sizes that can fit between truss chords for various truss depths. I was annoyed that the truss company had not included a clear path for running metal ducts.

Alpine engineered products now itw referred these to floor trusses as system42 trusses. Using floor joists as return ducts by panning can cause leakage because negative pressure in the cavity will draw air from the outside into the cavity through the construction joints of the rim area at the end of the joist cavity. Hvac chases in floor trusses hvac chase. Stuart lewis from alpine engineered products tells us.

It s possible to order special roof trusses called plenum trusses designed to accommodate a duct chase near the attic floor. I specified open web trusses for my new house in part to simplify the installation of mechanical systems. There simply wasn t a way to get from the mechanical room to the other end of each floor using metal. See sbca s ttb floor truss fact sheet.

Maximum span to depth ratio of 1 to 20 example 14 truss should not exceed 23 4 span spacing may be adjusted to accommodate longer spans maximum 24 duct chase on flat wise trusses minimum duct chase offset from the bearing is of the span. Floor trusses have built in openings which can be used to install hvac ductwork plumbing lines and electrical wiring.