Types of Air Conditioners

Air conditioning applications can be broadly divided into comfort and process.

Comfort applications aim to provide a building indoor environment that remains relatively constant and within a range preferred by its inhabitants - this in spite of changes in external weather conditions or internal head loads.

Process applications aim to provide a suitable environment for a process being carried out, regardless of internal heat and humidity loads and external weather conditions. Although often in the comfort range (air craft air conditioning for example), it is the needs of the process that determine conditions, not human preference. Hospital operating theatres, clean room environments, breeding facilities and computer data centres are areas where process applications would be required.

In both comfort and process applications the objective may be to not only control temperature, but also humidity, air quality and air movement from space to space.

Types of air conditioners available:

• Window / Wall type: This system is designed to fit through a hole in a wall or in a window frame. It is also known as a ‘self-contained’ air conditioner as the ‘indoor’ (evaporator) and ‘outdoor’ (condenser) parts are encased in a single housing. It is necessary to install this all-in-one air conditioner on an external wall/window in order for the heat to be disposed of via the back of the unit (condenser section).
• Split type: This type comprises an indoor unit (Fan Coil Unit / Evaporator) and an outdoor unit (Condenser Unit). There are a number of indoor split type air conditioners, i.e.
• Wall Mounted (mid-wall split)
• Ceiling Mounted (cassette split)
• Ducted type

The capacity of an air conditioner is a term used to measure the cooling (or heating) time. The capacity required from an air conditioner differs from region to region and the amount of air it has to cool. Therefore, one must choose the correct unit by calculating the heat load.

Type of air conditioners suitable:

Window / Wall Unit : Self-contained A basic entry level air conditioner. This all-in-one unit is ideal for ‘smaller’ spaces such as offices or homes with an area not exceeding 48m².

Split Type Unit : Midwall This air conditioner is purpose-designed for most offices or homes with an area not exceeding 60m² and has more features than the Window / Wall unit. It is also quieter but more expensive.

Split Type Unit : Ducted This air conditioner has one indoor unit mounted in the ceiling cooling one or more areas via ducts to a grille exposed on the ceiling or wall. A cost effective method for multiple areas.

Split Type Unit : Cassette This air conditioner has one indoor unit mounted in the ceiling with an exposed grille on the ceiling. An ideal solution for shops or large open plan areas.

Air conditioners are technically complex products that require regular maintenance. Failure to heed these requirements could result in reduction of product life span as well as breakdowns of expensive parts - just like a motor vehicle.

Recommendations on maintenance include:

• When choosing a position for an air conditioner, bear in mind the need for easy access in order to carry out maintenance work
• If an unusual decrease in cooling / heating capacity occurs, turn off the air conditioner and contact ACS. This will avoid expensive repairs.
• Air conditioners are designed to function when outside temperatures are above zero. Serious damage can occur to the unit if operated at outside temperatures that are below zero.
• Ensure cleanliness of indoor and outdoor units
• Check your air conditioners at least once a month and if necessary, clean or replace the indoor filter units
• Contact ACS at least every six months to carry out any required maintenance

Health implications:

A poorly maintained air conditioning system can occasionally promote the growth and spread of micro-organisms such as Legionella pneumophila, the infectious agent responsible for Legionnaires' disease or thermophilic actinomycetes. However, as long as the air conditioner is kept clean, these health hazards can be avoided.Conversely, air conditioning - including filtration, humidification, cooling, disinfection etc. - can be used to provide a clean, safe, hypoallergenic atmosphere in hospital operating rooms and other environments where an appropriate atmosphere is critical to patient safety and well-being.

Air conditioning can also have a positive effect on sufferers of allergies and asthma.