Plenum ventilation in buildings
To help develop this article click ‘Edit this article’ above.
Plenums are air compartments or chambers that are sometimes found in buildings, either above suspended ceilings, in the gap between the ceiling and the floor slab, or below raised floors in the gap between the raised floor and the floor slab. They form part of the ventilation system for the building.
They may be supply or return plenum, and may serve either an entire building, or a specific zone in a building. Supply plenum supply ventilation air to the occupied space, whilst return air is generally extracted through ductwork. Conversely, in return plenum the air is generally ducted to the space, whilst the return air is extracted through the plenum.
Underfloor air distribution (UFAD) uses the underfloor plenum beneath a raised floor to provide ventilation air through floor diffusers directly to the occupied zone. The air spreads across the floor forming a reservoir of fresh, cool air. Any sources of heat (such as people or computers) generate a thermal plume lifting contaminated air to high level where it can be removed from the space. See Underfloor air distribution for more information.
Plenum can give good flexibility for the layout of buildings. However, they can provide a space within which fire can spread, particularly because of the air supply they offer, and so they may be required to include fire and smoke detection, and potentially combustible material (such as cables) may be controlled. They can also create a pathway for the transmission of sound between separate spaces.
 Related articles on Designing Buildings Wiki
- Active thermal mass.
- Air handling unit.
- Chilled beam.
- CIBSE Case Study Olympic Velodrome.
- CIBSE Case Study Ortus Learning and Events Centre.
- Ground preconditioning of supply air.
- Herringbone strut.
- Floating floor.
- Floor plenum airtightness.
- Mechanical ventilation.
- Night time purging.
- Raised floor.
- Sprung floor.
- Suspended ceiling.
- Thermal labyrinth.
- Thermal mass.
- Underfloor air distribution
Featured articles and news
The origins, evolution and future of Level 3 BIM.
For new and returning Urban Design students, check out our article list divided up into the modules you'll be studying.
Report states that health of urban dwellers could be significantly improved by rethinking transport design.
The Kremlin, the centre of Russian power, includes some of the country's finest architecture.
Report launched outlining steps for a national infrastructure system that is efficient, sustainable, and delivers until 2050.
A review of Justin Bere's concise and well-presented introductory guide to Passive House.
This article describes in detail the tender process for a typical commercial construction contract.
What is energy storage, what are the different types and what is its future?
MAD Architects reveal their designs for a state-of-the-art concert hall in Beijing.
Take a look at BIG's designs for two twisting towers in New York City.
'The filing cabinet' which was labelled one of the best British buildings of the 21st century.