1. AIR HANDLING SYSTEM © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

2.  Hello, I want to show you an air handling system. This system delivers and controls the flow of air to and from the air conditioned space. The basic parts that make up the air handling system are: supply air fan supply air fan air ducts air ducts air outlets and/or grilles air outlets and/or grilles baffles baffles filters filters return air fan. return air fan. Let's look at each of these. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

3.  The supply air fan causes the air to pass through the evaporator and then delivers the cooled air to the air conditioned space. Supply air fans are usually centrifugal fans and, in most cases, use the induced air principle to draw the air through the cooling coil. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

4.  Air ducts used to deliver the air to the air conditioned space from the cooling unit are called supply air ducts.  Air ducts that return the air to the cooling unit for re- cooling are called return air ducts.  Other types of air ducts are fresh air ducts and exhaust air ducts. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

5.  Air outlets or grilles are fitted to air ducts to control the air flow from the duct to the air conditioned space. They often have a way to allow adjustment of the quantity of air leaving the outlet and also to control the direction of the flow of the air. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

6.  Baffles are fitted inside the ducts to adjust the amount of air flowing past a given point. Baffles are throttling devices. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

7.  Filters are fitted in the return air duct to filter out particles prior to the air entering the evaporator. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence

8.  Return air fans draw the air from the air conditioned space and deliver it to the cooling unit via the return air duct for re-cooling. These fans are only found on very large systems. © Commonwealth of Australia 2010 | Licensed under AEShareNet Share and Return licence