2020年9月8日 · The plenum is the space or structure the air flows in in an HVAC system. Most often in commercial buildings the space above the ceiling is the return plenum for the HVAC system (as opposed to ducted returns). A ceiling that uses the space above the tiles as the return plenum is usually referred to as a plenum ceiling.

2009年10月17日 · 2018 IMC 602.2.1.7 Plastic plumbing piping and tubing. Plastic piping and tubing used in plumbing systems shall be listed and labeled as having a flame spread index not greater than 25 and a smoke-developed index not greater than 50 when tested in accordance with ASTM E84 or UL 723.

2023年4月4日 · If the system is using return duct from RTU to a ceiling grid register, it is NON plenum. If no return into grid, and only an open return duct at bottom of RTU and then non duct registers in ceiling grid, it is Plenum. Commercial buildings in the States do both. I have never seen anyone use Tech cable for RTUs.

2009年10月17日 · Any fiberglass that may be picked up in the air flow of the return air plenum would be miniscule and would likely have to pass through the reurn air filters on the unit before being discharged through the fiberglass duckwork located on the supply side.

2011年11月2日 · Plenum ceiling Jump to Latest 10K views 19 replies 8 participants last post by raider1 Nov 3, 2011

2023年3月14日 · There's nothing in the NEC that prohibits a receptacle in the ceiling. You could not leave a fixed appliance cord and plug connected up there, that would break the rule against flexible cords. The wiring method and the box would have to be suitable for the ceiling's fire rating, so no romex or pvc if it's a plenum ceiling.

2013年4月17日 · Informational Note No. 1: The space over a hung ceiling used for environmental air-handling purposes is an example of the type of other space to which this section applies. Informational Note No. 2: The phrase “Other Spaces Used for Environmental Air (Plenum)” as used in this section correlates with the use of the term “plenum” in NFPA 90A-

2010年5月18日 · Type VB Construction; fully sprinklered Mixed use Bldg; two story structure; the first floor day care center has two forced air furnaces which are trying to utilize the above the drop ceiling space as a return air plenum. The space contains …

2009年10月16日 · Just a thought for discussion since the code for materials in a plenum is over 60 years old that I am aware of, and smoke detection has improved dramatically over the last twenty years. 606.2.2 Common supply and return air systems.

2015年4月27日 · UPC 2009 1210.2.2.1 Ceiling Locations. Gas piping shall be permitted to be installed in accessible spaces between a fixed ceiling and a dropped ceiling, whether or not such spaces are used as a plenum. Valves shall not belocated in such spaces.