Portable Air Conditioning 1: What is Portable Air Conditioning? The easiest way to secure instant comfort cooling in the office or home. They cool air in the same way as fixed air conditioning systems but without disruptive and costly installation. 2: How do they work? Portable Air Conditioners work by taking the heat from a room and expelling it to the outside either through an exhaust hose (Monobloc) or by flexible refrigerant lines (Split type) connected to an external condenser. Both types when connected to a normal 13A power supply, begin to emit a stream of cool air within seconds. Monobloc units can satisfy a wide range of average room requirements. Split Units are used for bigger rooms or where extra cooling capacity is required. 3: How do I know what size of unit I require? The cooling capacity of air conditioners is measured in BTU's or Watts and is volume related. As a rough guide, multiply the Length x Width x Height of the room to get the cubic capacity. The multiply by 4 if you are working in feet and Btu's/hr or 40 if you are working in metres and watts. This gives you the approximate cooling capacity you require. 4: What else do I need to consider? In addition to the room size you have to take into account the heat from electrical appliances such as computers, photocopiers. Often the major contributor is "solar gain" which is the amount of sunshine that comes into the room through the windows or from the roof. The number of people in the room is also a factor that needs to be considered. 5: What happens if I buy a smaller unit than is needed? When the heat load in the room is greater than the cooling capacity of the air conditioning unit it would only operate as a "spot cooler". It would supply a stream of cool air locally but would not reduce the temperature in the room significantly. 6: Where can I use a portable unit? There are a few restrictions other than finding space in the room and a means of expelling the heat to the outside. 7: How much do they cost to run? Most small Monobloc units use about 1 unit per house or less. Split units are a little more depending on size. At current rates this is about 7p or 10p per hour if at full power continuously. 8: How long can I make the temperature? The more cool capacity applied, the lower the temperature falls but there are practical limits. On most machines this is around 21C even though the digital thermostat will often display 16/18C. Most thermostats are not calibrated to an absolute scale but allow the user to determine the comfortable conditions for them and set their thermostat accordingly. 9: How noisey are they? Decibel levels are typically within the upper 40's. But consider that an ordinary conversation is 45dB and that street noises are at 60-70dBm, then these units are barely noticable and are not obtrusive.