Air Conditioner – A system that keeps air cool and dry.
BTU – British Thermal Unit, a measure of heat energy. It is the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit.
Chloroflurohydrocarbons (CFC) – A fluorocarbon with chlorine, formerly used as a refrigerant before its environmental effects were realised.
Compressor – A machine for compressing gases; especially air.
Condenser – An instrument for condensing air, consisting of a cylinder having a movable piston to force the air into a receiver, and a valve to prevent its escape.
Controller – The panel that controls the air conditioning system. In an installed system it is usually wall mounted with a temperature display.
Dehumidifier – A dehumidifier is simply an air conditioner that has both its hot and cold coils in the same box. A fan draws the room’s air over the cold coil to condense the moisture. The dry air then passes through the hot coil to heat it back up. A dehumidifier can be useful in environments containing sensitive electrical equipment like computer server rooms.
Enhanced Capital Allowances (ECA) – A tax relief given through the tax system by reducing the taxable profits of the business. The ECA scheme builds on existing statutory provisions, under which businesses may obtain tax relief, in the form of capital allowances, for their investment in plant and machinery.
Evaporation – The process by which any substance is converted from a liquid state into vapor.
Institute of Electrical and Electronics Engineers (IEEE) – The IEEE is a non-profit, technical professional association of more than 360,000 individual members in approximately 175 countries.Through its members, the IEEE is a leading authority in technical areas ranging from computer engineering, biomedical technology and telecommunications, to electric power, aerospace and consumer electronics, among others.http://www.ieee.org/.
Heat Exchanger – A device that transfers heat from one liquid to another without allowing them to mix.
Heat Reclaim Ventilation (HRV) – With an HRV system temperature and humidity are efficiently exchanged between supply and exhaust air. This process recovers energy losses and considerably reduces the air conditioning load.
Heating and Ventilation Contractors Association (HVCA) – Professional body for companies involved in the heating and air conditioning industries, members must under go an inspection of their work and vacilities. http://www.hvca.org.uk/
Humidty – The moisture in the atmosphere which is perceptible to the eye or touch. The humidity is determined by the quantity of water vapour in the air.
Hydroflurocarbon (HFC) – A fluorocarbon emitted as a by-product of industrial manufacturing. It has been suggested as a replacement for thechlorofluorocarbon (CFC) coolant gas used in chillers and air conditioners.
Local Area Network (LAN) – More expensive modern air conditioning systems can be controlled remotely over a digital network, allowing one controller to monitor and maintain the climate across a whole building.
National Inspection Council for Electrical Installation Contracting (NICEIC) – Contractors approved by this organisation must comply with British Standard BS 7671. http://www.niceic.org.uk/
Portable Air Conditioner – Small movable units that can be hired to supplement a rooms existing cooling. These are often a useful short term solution during the Summer months.
Variable Air Volume (VAV) – Variable Air Volume or VAV systems control the air volume. The simplest control is a simple On-Off control of fans but the complex damper controls are more common as variable speed control of fans is the most economic method to control the air volume.
Variable Refrigerant Volume (VRV) – Is a type of system consisting of anywhere up to 40 indoor units connected to one outdoor condensing unit. The refrigerant flow is varied by using either an inverter controlled variable speed compressor, or multiple compressors of varying capacity to respond to changes in the cooling or heating requirement. VRV systems are suitable for offices, restaurants, hotels, theatres, hospital, universities and industrial buildings among others. They are highly versatile and come with a variety of indoor units.
Refrigerant – A substance used to provide cooling.
Room Temperature – This is an often quoted figure of around 20°C.
Subcooling – To cool a liquid below its freezing point without it solidifying into ice.
Superheat – To heat a liquid above its boiling point without converting it into vapor.
Thermostat – A device for automatically regulating temperature by starting or stopping the supply of heat.
Electrical Industries Installation for Basic 