Technical note on portable air conditioning systems
There are two main types of portable air conditioning unit. The split type (shown on this website) has an indoor unit which passes air across a cold coil to cool it. By re-circulating in the room through the coil the temperature of the room is reduced. Refrigerant is circulated between this indoor unit and an outdoor unit to carry the heat outside. The coil in the outdoor unit is hot and through the fan assisted circulation across this coil the heat from the room is dissipated outside. As the room air passes across the cold coil moisture is condensed out on the coil and this condensate is collected in a tray for disposal, normally by pumping to the outdoor unit where it is discharged. In this way the humidity in the room is reduced, contributing to the comfort levels for occupants in line with the psychrometric analysis.
The other type of portable air conditioning unit is a monobloc unit. This is also displayed on this website. As the name implies, that the whole unit is contained in a single cabinet. The principal difference in operation is that heat is discharged from the room by a warm exhaust hose taken to a window or other outlet from the room. In this way the heat from the room is discharged outside.
The cooling output is measured in either Kilowatts or BTU/hr. The conversion from one to the other is that there are 3412 BTU/hr is a Kilowatt.
Units which will operate from standard 32amp wall sockets range from 2.2 KW up to 10.3 KW. Units intended for general office or domestic use are normally below 5 KW with the larger units being more industrial and noisier. Typical insatllations can be found in our case studies section.
Air conditioning units as described above should not be confused with evaporative coolers.
Evaporative cooling air conditioner systems
All conditioning moves heat from inside the cooled area and discharges that heat elsewhere. An evaporative cooler does not do this but should be used where sufficient ventilation is available for a high turnover of the atmosphere in the cooled area. The more simple evaporative cooler should not be confused with an air conditioner though it can be very effective when operating in low humidities. Evaporative cooling is simply a fan which blows through a wet filter to evaporate water into the flow from the fan, so reducing the temperature. The atmosphere passing through the evaporative cooler has moisture added and in an eclosed space it will become very humid to the point where the cooler will stop functioning as a cooler and become only a fan. Evaporative coolers should therefore only be used in very well ventilated areas. This makes them unsuitable for office or server room use. They are very useful to provide spot cooling of people working outside and for cooling areas such as marquees where the use of a large fan and a lot of air movement will not be a problem.