Information about indoor space, buildings, cooling, chillers, pipes, ahu, air handling unit, filtration, drain pipe, insulated, insulation, condensation, vibration, fans ...

How Big Buildings Circulate Air?

By Thomas Yoon

How do big shopping complexes, offices and commercial buildings cool their indoor space?

For big buildings, we need big cooling capacities. Central air-conditioning systems using chillers are used. Chilled water is the most convenient way to collect the heat from the indoor spaces. We just need pipes. Miles and miles of them.

Chilled water from the chillers is about 44 degree Fahrenheit (about 7 deg C). In order for the room heat to be transferred to the water efficiently, the air in the room is circulated through tubes containing flowing chilled water.

That is the main function of the air handling unit in a central air-conditioning chilled water system.

Another function of an air handling unit is to clean the air. It does this by filtration.

A most basic air handling unit, or AHU, contains a fan, a cooling coil, and an air filter enclosed in a box-like structure.

Normally, air contains moisture. When air is passed through the cooling coils, water usually condenses out at the surfaces of the coils. Collection pans are installed below the cooling coils to collect any condensed water. This water is removed through drain pipes.

The whole box-like enclosure is heat insulated to prevent condensation at their surfaces. Many enclosures are sound insulated and are installed on vibration damping pads. Many others have damper vanes for controlling the air flow.

The most common AHU's have their fans and motors enclosed inside the box. Other specialized AHU's have motors outside the box. There are some with steam coils too.

They can be made in numerous configurations too. Tall, short, wide, long, supply up, supply to side, and so on....

Until next time…

Back to Tech Marketing Ezine Articles Page
Subscribe to Tech Marketing Ezine