Air conditioning

Essay by starwars February 2007

download word file, 4 pages 4.0

Air conditioning is achieved by developing the principles of moving air in ducted ventilation systems to include a number of physical and scientific processes which enhance the air quality. The objective is to provide and maintain internal air conditions at a predetermined state, regardless of the time of year, season and external atmospheric environment. For buildings with human occupancy, the design specification is likely to include an internal air temperature of 19-23`c and relative humidity between 40 / 60%. Theoretically most "air conditioning" should be referred to as "comfort cooling" as the air is only cooled or heated, with no humidity control or extensive filtration of the air. 7

The system used in the Bicentennial building is a VRV system. VRF and VRV systems have been in use since the late 1990's, and are becoming the industry standard for providing heating and cooling in commercial blocks nowadays due to their high energy efficiency.

VRV stands for Variable Refrigerant Volume (or Variable Refrigerant Flow) and is a type of air conditioning system consisting of anywhere up to 40 indoor units connected to one outdoor condensing unit. The refrigerant flow is varied by using an inverter controlled variable speed compressor, or multiple compressors to respond to changes in the cooling or heating requirement.

There are two types of VRV air conditioning systems:

* Two-pipe systems, usually applied to open-plan areas, retail stores or offices, which require heating or cooling during the same operational periods

* Three-pipe systems, where there is a requirement for some areas to be cooled and others heated.

An advanced controller enables switching between heating and cooling in two-pipe systems and in 3-pipe systems it manages the indoor units to operate independently in heating or cooling mode. 8

The VRV multi split air conditioning system (cooling only) found...