Air Handling Unit (AHU)

An air handling unit (AHU), is a device used to condition and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system. The unit comprises a large metal box containing a blower, heating and/or cooling elements, filter racks or chambers, sound attenuators, and dampers. AHUs are easily placed in the ducts of a route.

Schema Properties example - AHU

Air handling units are essential components within HVAC systems, they are a collection of smaller elements assembled together, and placed as one component.Mechanical discipline provides extensive libraries in which to browse and select as an off the shelf item. They are individually designed and sized for a specific load or application.

Selecting an AHU in the AHU Library list and the Place AHU tool on the in AHU Builder toolbar activates the Place Component settings dialog, where you can manage the schema parameters (DG instance properties). Also, the contextual Placement tab appears on the ribbon, that provides placement settings options for the currently selected fitting.

The generic placement settings, along with the unique set of dimensional and data parameters from the datagroup system provide the core workflow used to accurately position mechanical components within a system.

AHU Library listing default AHUs

AHU Builder utility when loaded with BentleyAHULibrary provides a series of readily available AHUs bundled in the application. They can be picked and placed as required. The AHU Placement utility places a selected AHU and the AHU Builder allows creating a new, modifying and customizing an AHU. AHUs are available in two categories based on their shape type. Multi-end AHUs are also available up to 5 ends. Inline AHUs can be configured for custom chambers and connections. Stacked AHUs are double decker units mounted one over another. They provide two level configuration for required chamber units including Blower, Pre Filter, Mixing Chamber, Cooling Coil, Heating Coil, Humidifiers etc., and corresponding HVAC/Piping connections. Beside default devices, the AHU Builder utility provided in Mechanical discipline allows you to build AHUs of desired configurations and customize them.

AHUs share many of the common properties.

Notable Properties

Connection End Type – The end conditions of fittings are set to flange, male or female connections with full dimensional control by setting the End Type property. Also, the two ends are independent, and may have different connections. For example, the value fl-2;fe-.13 creates a flange at End1 with size 2, and a female connection at End2 with a clearance of .13.
Cell Symbol Name – Sets model cell from cell library to the component by fitting cell proportionally to extents of device.
Modular Type – Condensing or Atmospheric types modular design gives flexibility in constructing a compact modular radiator. Condensing type modular adds drain on the surface area side.

The list of Air Handling Units in AHU group is compiled in the Air Handling Unit types topic.