Louvers
Blades, in some cases adjustable, put in ducts or duct entries to handle the volume of air stream. The phrase could also refer to blades in a rectangular body put in doors or walls to allow the motion of air.
Make-up air device (MAU)
An air handler that ailments a hundred% exterior air. MAUs are commonly utilised in industrial or industrial settings, or in “once-via” (blower sections that only blow air one particular-way into the creating), “reduced stream” (air managing units that blow air at a reduced stream price), or “key-secondary” (air managing units that have an air handler or rooftop device connected to an incorporate-on makeup device or hood) industrial HVAC units.
Packaged terminal air conditioner (PTAC)
An air conditioner and heater air conditioning put together into a solitary, electrically-driven device, commonly set up via a wall and often found in resorts.
Packaged device or rooftop device (RTU)
An air-managing device, described as both “recirculating” or “once-via” layout, made exclusively for outdoor installation. They most often contain, internally, their own heating and cooling devices. RTUs are incredibly widespread in some regions, specially in solitary-tale industrial buildings.
Plenum space

See also: Plenum chamber

An enclosed space inside of a creating or other construction, utilised for airflow. Often refers to the space in between a dropped ceiling and the structural ceiling. Distinctive from ductwork as a plenum is element of the construction by itself.
Thermal zone
A solitary or group of neighboring indoor areas that the HVAC designer expects will have very similar thermal masses. Creating codes could require zoning to preserve electricity in industrial buildings. Zones are described air conditioning in the creating to minimize the selection of HVAC subsystems, and consequently first expense. For case in point, for perimeter offices, relatively than one particular zone for just about every workplace, all offices going through west can be put together into one particular zone. Compact residences commonly have only one particular conditioned thermal zone, in addition unconditioned areas these kinds of as unconditioned garages, attics, and crawlspaces, and unconditioned basements.
Variable air volume (VAV) program
An HVAC program that has a secure supply-air temperature, and differs the air stream price to meet up with the temperature requirements. In comparison to CAV units, these units waste significantly less electricity via unnecessarily-high air conditioning enthusiast speeds. Most new industrial buildings have VAV units. VAVs could be bypass variety or strain dependent. The strain dependent variety VAVs preserve electricity though the two the sorts assistance in keeping temperature of the zone that it feeds.