All AC systems have the same working principle, but central air conditioning is specifically designed to cool the entire home by distributing conditioned air through ducts and vents. There are some AC models which move chilled water through heat exchangers and pipes.
The most popular type of AC system is the split-type which has a compressor and condenser that are located in the outdoors and connected to the evaporator in the air handler unit indoors through refrigerant lines. The air handler unit is basically a metallic box containing vibration isolators, controls, humidifier, mixing chamber, heating and cooling elements, filters and a blower. In a packaged system, however, everything is located within a single outdoor unit.
Heat extracted from the home is dumped outside in a compressor cycled that is very similar to the refrigeration process in a conventional fridge. A highly compressed refrigerant fluid is released into the evaporator through an expansion valve and transforms into a gas thereby absorbing heat from the surroundings which is then dumped outside before the gas is compressed once again. A repetition of the same cycle is what brings about the cooling effect.
As air passes through the evaporator, moisture is extracted, condensed and drained through the household drainage system.
Compared to other types of air conditioners, central AC systems have a number of benefits since air is drawn from different parts of the building through a filter. Lint particles and dust are removed from the air by the filter. Some special filters can also get rid of microscopic pollutants which are known to have an adverse effect on a person’s health. Since the unit containing the compressor is located outside the building, noise is reduced.
While central AC’s may be very efficient in cooling a building, the user needs to work hard to attain the highest SEER rating possible (ranging from 10 to 17). SEER is an acronym which stands for Seasonal Energy Efficiency Ratio. Energy Star-labelled ACs normally have a SEER rating of over 12 and 13 for a single unit AC system and split air conditioning respectively. Second-hand AC units often have lower SEER ratings, which means that they are uneconomical, so you may want to consider this before deciding whether to buy a pre-owned unit or a new AC system.
Some of the most popular manufacturers of the best ducted air conditioners include York, Carrier, and Lennox. If you need more information about these brands, you may want to consider getting in touch with the local HVAC dealership.