Air Distribution System Efficiency

Air Handling Unit and Fan Coil Unit Problem 1

Broken fan belt

Blue / Grey formicary corrosion on Al-Cu cooling coil

Design

The design of a system must consider the energy efficiency and maintainability when selecting the system and its components. The design of the AHU must comply with ANSI/ASHRAE/IES Standard 90.1 (see also SS 553).

Fan power limitation requirements in mechanical ventilation systems as per SS 553 must also be complied with (see also AS1668.2).

Specify minimum performance for air-conditioning equipment (including test procedure) as per SS 530.

Construction

SS 652: F.6.2.1.1
It is presupposed that the installation (and subsequent operation) of the AHU is in compliance with statutory and regulatory requirements.

SS 652: F.6.2.1.2
For the vibration control of fan systems refer to CP 99 for the installation / commissioning in accordance with ISO 9996 or equivalent.

SS 652: F.6.2.1.3
Install / Integrate AHU system components (e.g. VFD control dampers / actuators) off-site to ensure a quality installation.

Maintenance

SS 652: F.11.3.1.1
– Clean dirt from impeller, fan scroll and blower blade, washable filters, filter frames, and AHU frame slot.
– Clean the cooling coil face with water. Flush with a chemical cleaner but avoid over dosage. A chemical was should be carried out, followed by a thorough cleaning with water.
– Check for any dents on the coil fins. Comb / Replace as needed.
– Clean off any hardened and dirty grease or grime from fans and the motor shaft and lubricate properly.

Maintain AHU rooms in accordance with SS 553, AS 1668.2