Air tightness level (buildings)
The degree of air leakage or air infiltration in a building.
An audit is a systematic, independent and documented process for obtaining evidence and evaluating it objectively to determine the extent to which defined criteria are fulfilled.Back to top
Back-end isolation valves (heating system)
Isolation valves: valves that control the distribution of heating or hot water to specific areas or zones.
A control thermostat normally used in radiant heating systems.
Blank screen-saver (computers)
Computer screen saver that leaves the screen blank
BMS (Building Management System)
An automated system for managing a building's services and other related aspects
Boiler flow temperature
The temperature at which the water leaves the boiler in a wet heating system.
British Thermal Unit: a unit for measuring the quantity of heat energy necessary to raise the temperature of one pound of water one degree fahrenheit.
Units or systems used to control building services such as heating or lighting
Burner damper (boilers)
A moveable plate used to control air flow to the burner in a boiler
Back to top
The process of checking and re-establishing the accuracy of a measuring instrument, e.g. a digital thermometer
Calorifier (hot water)
A pressure vessel containing tubes through which hot water passes.
Commission for Energy Regulation
Compact Flourescent Light
Combined Heat and Power
Circulating pump (hot water)
Pump used to keep (hot) water circulating through a distribution system
Carbon Dioxide – a greenhouse gas produced as a result of burning fossil fuel.
Co-efficient of Performance (COP)
A measure of the effectiveness of an air conditioning unit (or chiller) in converting electricity into cooling or heat. Once you buy a unit, the COP cannot be changed. For a given appliance, the COP in cooling mode will differ from the COP in heating mode. Usually the COP will be supplied with an appliance’s technical literature. If it is not given it may be calculated simply: COPcooling = rated cooling output [kW] / rated electricity input [kW].
Condenser (outdoor unit)
The device in which a refrigerant condenses from a gas to a liquid when it is depressurized or cooled in an air conditioning, refrigeration or heat pump system
The coils through which a refrigerant is circulated and releases heat to the surroundings in an air conditioning, refrigeration or heat pump system.
CRT computer screen
Cathode ray tube computer monitor. These are the traditional 'bulky' screens as opposed to the modern flat screens.
Cumulative sum. A technique for analysing energy data that uses the difference between the base line (expected or standard consumption) and the actual consumption over the base line period of time.
Back to top
Department for Communications, Marine and Natural Resources
A unit for measuring the extent to which the outdoor daily average temperature falls below an assumed base temperature, usually 15.5 C. They are used to take into account the changes in the weather (temperatures) in analysing heating energy
Domestic hot water
Thermometers that display results in digital format
Distribution System OperatorBack to top
Electro-magnetic control gear
Lighting control gear that consists primarily of transformer-like copper windings on a steel or iron core.
Eco Management and Audit Scheme
Energy Management System
Energy MAP audit
An audit of the operation of the Energy MAP
Energy performance indicator
A value against which you compare your energy performance
A US and European programme for the classification of energy efficient products
Energy Star Label
The label used by the Energy Star programme to identify energy efficient products
A group established to manage energy within an organisation
Labels used to identify environmentally preferable products
Energy Services Company - a company that manages an organisation's internal energy supply services on an outsourcing basis.
The environment label of the European Union used to identify environmentally preferable products and services
European Union Energy Labels
A European Union label that provides information on a product's energy consumption and rates it on a scale of A to G, with A being the most efficient.
Evaporator (Indoor unit)
A mechanical device that transforms a liquid into a gaseous state
Exposed thermal mass
Refers to a building's capacity to absorb heat energy. Materials such as concrete slabs have a high thermal mass, and if left exposed within a building can be used to absorb heat and therefore moderate internal temperatures.
Energy MAP Review
A review of the operation of the Energy MAP. Top management are responsible for carrying out the management review of the Energy MAP
Back to top
Fan coil unit
A unit in which a fan blows air over a heat exchanger coil containing a circulating fluid and distributes heat or cool air to different areas.
FLA (Full load amps)
The current (amperage) drawn by a motor when operating under full load
Modern computer monitors that are 'flat' in appearance and use less energy than the traditional computer monitors. These employ TFT LCD technology used in portable computer screens.
A moveable plate used to control air flow in the flue
Flue gas analyser
A devices for analysing the gas resulting from the combustion of a fuel that is emitted to the flue
Frost protection thermostat
A heating system thermostat used to prevent damage in the event of frost and low external temperatures.Back to top
A portable device that can be freely attached to an electric cable and used to measure current.
Gigawatt hourBack to top
The removal of heat from a source or area
The state of activity of a computer when least energy is being used
High bay fittings (lighting)
Usually refers to industiral or retail lighting mounted at about 5m or more above ground level.
High frequency control gear
Lighting control gear that typically operate flourescent lamps at high frequencies. These are based on state electronic components and help reduce lighting energy consumption.
Heating, Ventilation & Air ConditioningBack to top
Infra-red coated halogen lamps
A halogen lamp is an incandescent lamp with a filament that is surrounded by halogen gases. An infra-red coating can be placed on the filament tube to redirect infra-red heat back on to the filament thus increasing its temperature and resulting in less electrical energy being required.
Interdisciplinary design team
A building design team that contains members from different disciplines, such as architects, engineers, quantity surveyors, etc.
The international standard for environmental management systems.Back to top
JBack to top
Kilo volt amps, a unit of power
Kilowatt hourBack to top
Light emitting diode - now being increasingly used in certain low energy lighting applications.
Bacteria that causes Legionnaire's Disease
A device that measures the light level (illuminance) at a surface or location.
Liquefied natural gas
Low voltage halogen lamps
Low-voltage tingsten-halogen lamps are incandescent lamps that use a halogen gas surrounding the filament and operate at 6v, 12v and 24v ratings.
Liquid Petroleum Gas
Low temperature hot water
The unit used to measure 'Illuminance', which is the amount of light falling on a surface of unit area. One lux is equal to one lumen per square metre.Back to top
Mains voltage mini-CFL fittings
Small compact flourscent fitting that can be connected to the mains voltage.
Maximum Demand is the highest level of electrical demand in the monitored period. This is monitored during particular intervals and used for a specific type of electrical tariff where a special meter records the maximum demand for electricity at short intervals, e.g. each half hour or fifteen minute period.
Maximum Export Capacity
Mechanical heat removal
Removal of heat from a building or process by mechanical means, e.g. by means of extractor fans
Maximum Import Capacity
Memorandum of Understanding
Meter Registration System Operator
Back to top
Natural heat removal
Removal of heat from a building or process by natural means, i.e. without the aid of mechanical or electrical plant or equipment.
Night hours (electricity tariffs)
The period of time during the night used for the application of certain electricity tariffs. Under Maximum Demand tariffs, day and night units are separately measured.
Night load (electricity tariffs)
Electricity load during night hours
Refers to a process of treating energy data in order to deal with external influencing factors.
Nitrogen oxidesBack to top
O & M
Operation & Maintenance
A site goal that is consistent with the energy policy and takes significant energy users and energy saving opportunities into account
A heating system control that adjusts heating start up times according to external weather conditions. Heating is turned on later on milder days as shorter warm-up times are required.
Back to top
Parameters and settings of the building control strategies
Criteria used to establish control strategies for building services. Critertia could include operational hours, daylighting, weather conditions and others.
The time taken for a project to recover its outlay. For energy saving projects, payback in simple terms is the capital cost divided by average annual savings.
Performance based specifications
Specification of a particular performance level for the item rather than identifying the technical characteristics in detail. In essence, it specifies the end result, but not how to achieve it.
Post project evaluation
The evaluation of a project after it has been implemented.
Power factor correction capacitors
Power factor is the ratio of actual power being used in a circuit, expressed in watts or kilowatts, to the power that is apparently being drawn from a power source. By installing capacitors the Power Factor can be altered.
A device for recording electrical power
Maintenance based on analysis of the condition of an item or facility that checks if it is operating as required, and if not, corrective action is taken.
Maintenance actions performed on the basis of a set time or run-time interval
Photovoltaic. PVs convert solar radiation (energy from the sun) into electricity.Back to top
QBack to top
R & D
Research and development
Mathematical notation for 'goodness of fit' or level of relationship between 2 or more variables
A heating system that transfers heat to objects and surfaces within a space primarily by (infrared) radiation
Rated cooling output
The cooling output of a device under specific or nominal operating conditions.
Rated electricity input
The electrical output of a device under specific or nominal operating conditions.
Renewable energy. This includes solar, wind, wave, hydro, geothermal and biofuels such as wood, waste, and energy crops
Refrigerant sight glass
A 'window' where you can observe the coolant liquid in a refrigeration circuit.
A technique for analysing energy data that analyses the association between one (dependent) variable and one or more other (independent) variables.
Reliability centered maintenance (RCM)
A process used to determine the maintenance requirements of a physical asset in its operating context. Essentially RCM prioritises maintenance according to the importance of an item and the probability of failure and matches these with the resources available.
Inputs into a process, including capital, labour and land
An assessment of performance and operationBack to top
The control of two or more equivalent items of plant in order to achieve optimum performance. For example, boiler sequence controls may operate two or more heating boilers in order to achieve optimum performance of the heating system.
Set point (temperature)
The point at which the desired temperature of a heated or cooled space is set
Short cycling (boilers)
A condition in which a boiler fires even though there may not be a real heating or how water demand
High pressure sodium lighting
Split air conditioning unit
These are small packaged air-conditioning units, often referred to as DX (direct exchange) units, or split a/c units. Each unit has an indoor unit (evaporator) and outdoor unit (condenser). They are usuaally installed to provide cooling, but are generally capable of heating too.
The condition in which an item of equipment is ready for operation but not in operation. Standby conditions should use less power.
Usually refers to meters that are not 'main' meters that directly record electricity supply in a sub-area of a site.Back to top
A detailed performance requirement (quantified wherever practicable) based on an objective. The target contributes to achieving the stated objective.
The payment scheme used for electricity/gas use.
The point at which the desired temperature of a heated or cooled space is set
Thermostatic radiator valves
Valves attached to a heat emitter or radiatior that directly control its temperature
Three phase load (3-phase load)
Phase is a term used to describe alternating current. To distribute AC power it is more efficient to use three circuits that are 'out of phase', with the result that there is always voltage in at least one wire. Three-phase power removes the need for a neutral or 'return path'.
Total productive maintenance
An approach to maintenance that brings different functions together such as operations, maintenance, purchasing and other support services to develop and implement a formal structure for maintaining a building, plant, fixtures and fittings.
Transmission System OperatorBack to top
Unit of Energy
The method used to measure energy delivered or consumed, this is usually the kilowatt hour (kWh)
Uninterruptible Power Supply (UPS) system
An alternative power source used to power equipment if normal power service is interrupted or falls below acceptable levels.Back to top
Variable speed drive
Motor drives that can operate at different speeds
Variable speed inverter
Variable frequency controller that controls drive speedBack to top
Wattless Charges are caused by the operation of specific electrical load on a site as some items using power may require an amount of wattless energy for their operation. Wattless charges can be eliminated by the installation of power factor correction capacitors.
Power that is 'borrowed' from the load and returned to the power source each cycle. Also called 'reaactive' power
A heating system control that adjusts the flow temperature in the system in response to changes in external temperatures
Winter Peak Demand Scheme
A scheme that offers electricity customers an opportunity to receive payment in return for committing to reducing their demand for electricity for specific hours during the winter months.Back to top
XBack to top
YBack to top
ZBack to top