Sep 26, 2018 · The return AHU in its simplest form has just a fan and damper inside. The fan is pulling the air in from around the building and then pushing it out of the building. The damper is located at the exit of the ahu housing and will close when the AHU turns off.

Aug 29, 2022 · Energy from waste return air before getting exhausted is used to cool or heat the fresh air entering the ahu through heat recovery system. The fresh air & return air are completely isolated or no moisture or odors can be transferred.

One of the primary functions of a packaged rooftop unit (RTU) or air-handling unit (AHU) is to provide a prescribed amount of outside air (OSA) to the conditioned space to comply with the ventilation requirements of ASHRAE Standard 62.

Aug 16, 2022 · Today, we'll explain the difference between a return air duct and an underfloor air plenum and compare and contrast their advantages and disadvantages. What is a Return Air Duct? A return air duct is a component of an HVAC system that returns conditioned air to the air handling unit (AHU).

The Return Air Carbon Monoxide sensor of the AHU will be monitored by the BMS to control the Fresh Air, Exhaust Air, and Return Air motorized damper in sequence to satisfy the Air Quality within the supplied area.

Sep 1, 2023 · The AHU with return air system is a specific type of AHU that incorporates return air capabilities. In this system, the AHU not only circulates fresh air but also recycles a portion of the indoor air.

Oct 1, 2024 · If they want to have tighter control on their balancing per AHU they may each have a return fan(s) for the return duct static. This could be as simple trying to overcome space constraints that limit ductsize or unit size.

Jul 20, 2022 · As you can see the Return air system has two options, it can return air back to the inlet of the supply, or it can exhaust the air outside. The rest of the air systems only have one option as shown by the directional arrows.

Supply air and return air ducts connect to the bottom (vertical discharge) or side (horizontal discharge) of the unit. Air handling units are configured to be either blow-through or draw-through units.

Mar 26, 2024 · The mixing box is also known as the return plenum box. You can opt for a mixing box or omit it depending on how you design the return and fresh air ducts. AHUs mixing box is not a mandatory component.