Reviews Computer Room Air Conditioner

In fact, the applications for portable air conditioning units are continually increasing for a number of reasons:

* to offset rising temperatures/global warming
* to maintain workforce productivity
* for better personal comfort
* for health purposes
* for business purposes such as to maintain stock temperatures
* to counteract the presence of computers, servers or other appliances

Therefore temporary air conditioning units now have a permanent place as must-have equipment in a business setting. In fact, the widespread business usage in the UK is one of the driving factors behind the uptake of AC units in many homes too - many people experience the benefits in their workplace and then wish to replicate that comfort in their home.

Whichever the setting, the basic principles of air conditioning are the same. The system comprises four elements: an evaporator, a compressor, condenser and an expansion value. These four components are all connected together with refrigerant piping. The refrigerant has a very low boiling point and to enable the evaporation a rise in temperature is necessary - this is provided by the ambient room temperature. As warm air passes over the evaporator the air temperature will drop and cool the room. The compressor draws the vapour refrigerant along and away from the evaporator and as it moves in to the condenser, it returns to liquid again. At this point, the refrigerant needs cooling using either water or air to prevent the system from overheating and the pressure rising too high. The liquid vapour is now passed through the expansion value to the evaporator and due to the narrowing of the pipework the pressure decreases and the refrigerant evaporates once more. To enable this evaporation, the warm air is needed (provided by the ambient air temperature) and the circuit begins again.

There are three main types of portable air conditioning unit, all of which operate in a similar way to the above method:

Exhaust tube units
In ET models both the evaporator and condenser are positioned within the room unit. The majority of the air that is passed through the unit is directed over the evaporator and returns back into the room, as cooled air. A smaller volume of air is passed across the condenser to cool the refrigerant gas. This air needs to be removed from the room as it becomes hot. An exhaust tube is used to remove this hot air via an opening in the room (usually through a window). In some cases the exhaust tube may be positioned into a false ceiling void. Advice should be sought before using this system.

Split type units (refrigerant)
These units are supplied in 2 parts, a room unit and a condenser. The room unit placed within the area to be cooled comprises of an evaporator and a compressor. The room air enters the unit and once passed across the evaporator is returned into the room as cooled air. The external unit which is connected to the room unit by a flexible pipe, contains the condenser which needs to be cooled by ambient air, therefore the external unit needs to be positioned outside of the room to be cooled. Typically the condenser is hung from a window.

Split type units (water)
These units are also supplied in two parts, a room unit and a heat exchanger. The principle in operation is very similar to the above. The major difference is that the condenser is placed within the room unit and cooled by water. The water is then circulated to the external unit (heat exchanger) via flexible pipes before returning to the room unit. The system is totally sealed and requires no further water once the unit is in place. The main advantage of this system is that the connection pipes can be extended - up to 30 metres - allowing the heat exchanger to be positioned away from the room unit.

When an existing system fails or we experience a heatwave, it can be tempting to hire the largest air conditioning unit available. However, it is always worth seeking guidance on the type and size or system for your individual circumstance to both maximise the effective removal of hot air and avoid unnecessary operating costs.