Glossary

 
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A.

Aico - Manufacturer of Heat and Smoke Alarms 

Air Conditioner - (AC or A/C in North American English, aircon in British and Australian English) is an appliance, system, or mechanism designed to extract heat from an area or provide heat to an area using a refrigeration cycle. The most common uses of modern air conditioners are for comfort cooling and heating in buildings or cooling only in transportation vehicles.

Portable Air Conditioner - Portable air conditioners differ from permanent aircons in that they do not have a heat exchange unit. Hot air is instead expelled from the room via ducting and a vent.

Air Curtain - An air curtain is a downward facing fan, typically mounted above an entrance to a building. It is intended to help keep outside air out and avoid cold draught by mixing in warm air from the air curtain.

Air Treatment - The phrase used to describe any process which changes the make up, temperature or humidity content of an environment's atmosphere, and alludes to such products as desk and pedestal fans, extractor fans, air conditioners, dehumidifiers and heaters. Gil-lec make the distinction between air treatment and heating on www.gil-lec.co.uk in order to facilitate easy navigation.

Airflow - Manufacturer of extractor fans.

Alarm
Carbon Monoxide Alarm
- There are different types of CO sensors which, because they work in different ways, have different characteristics. All Ei CO alarms use a new generation proven electrochemical cell type sensor. This sensor type has a low power requirement well suited for use in a battery powered alarm in order to avoid frequent battery replacement. The electrochemical sensor works by catalytic action in direct proportion to the amount of CO present. It has a minimum 5 year life expectancy with good immunity to contaminant gases.
Heat Alarm - Heat alarms are less likely to cause false alarm problems as they are not responsive to any type of smoke or fumes, only heat. Because of the potential for a slower response than smoke alarms, they should only be used in a fire alarm system that also includes smoke alarms, and all of the alarms must be interconnected. The BS 5839: Pt.6: 2004 recommends that heat alarms should be used in kitchens. It goes on to suggest that they may also have a role to play in the main living room but they should not be installed in circulation spaces or areas where fast response to fire is required. These are fixed temperature alarms which incorporate a thermistor sensor. The thermistor is a heat sensitive resistor, when the ambient temperature reaches a pre-set point of 58°C, the resistance is lowered and the alarm will sound. They are designed for use in areas where due to high levels of dust or fumes, a conventional Smoke Alarm is not suitable. They are particularly suited for use in a kitchen
(source of 40% of domestic fires), garages or boiler rooms. BS 5839: Pt:6 recommends the use of fixed temperature heat detectors in preference to ‘rate of rise' types due to the reduced risk of nuisance alarm which can be caused by opening hot oven doors etc.
Smoke Alarm - Smoke Alarms come in two basic types: Ionisation and Optical:
Ionisation Smoke Alarm - Ionisation type sensors are particularly sensitive to the almost invisible smoke produced by fast flaming fires. This makes them more liable to false alarm due to cooking fumes if sited in a hallway close to a kitchen. Ionisation alarms are less vulnerable to false alarms caused by dense tobacco smoke, excessive dust and insect ingress. The BS 5839: Pt.6: 2004 Standard recommends that ionisation alarms should not be used in hallways and landings,where there is a risk of false alarms caused by cooking fumes. Ionisation Smoke Alarms contain a small sealed ionising source which causes a small electrical current to flow through the air in the smoke chamber. Smoke particles entering the chamber reduce the current, this is sensed by the electronics and when a pre-set
threshold level is reached the alarm will sound.
Optical Smoke Alarms -  Optical sensors are more responsive to smouldering fires producing large particle smoke typical of fires involving furniture and bedding. They are more immune to invisible smoke produced by 'burning the toast' and similar cooking fumes. This makes them ideal for siting in hallways close to kitchens where false alarms from ionisation alarms may be a particular problem. The BS 5839: Pt.6: 2004 Standard recommends the use of optical alarms in circulation spaces of a dwelling, such as hallways and landings. Optical alarms are prone to false alarm if exposed to steam and should not be located too close to poorly ventilated bathrooms or shower rooms. Optical Smoke Alarms send a pulsed beam of infra red light through the smoke chamber periodically. If visible smoke is present, it scatters the light on to the photodiode light receiver and this is detected by the electronics causing the alarm to sound. Ei Optical Alarms are individually calibrated to ensure correct operation and to reduce the risk of nuisance alarm.
Radiolink Alarm - It is a totally new concept enabling smoke alarm systems to be interconnected without the need for cabling between the alarms. Instead, a radio signal is used to trigger all the alarms in the system.

Alarm Grading System - Six different grades of fire detection systems are defined and - generally speaking - the greater the fire risk the more comprehensive the system should be. Briefly, the Grades are as follows:
GRADE A - A full system with control and indicating equipment
installed to BS 5839: Part 1
GRADE B - Detectors and sounders using simpler specified
equipment
GRADE C - Detectors and sounders or alarms with central control
GRADE D - Mains powered alarms with an integral stand-by
power supply
GRADE E - Mains powered alarms with no stand-by
power supply
GRADE F - Battery powered alarms

Alternating Current (AC) - an electric current that reverses its direction at regularity occurring intervals. Homes have A.C.

Amplifier - Any device used for boosting, or strengthening an incoming signal.

Amp / Ampere - The ampere, in practice often shortened to amp, (symbol: A) is a unit of electric current, or amount of electric charge per second. The ampere is an SI base unit, and is named after André-Marie Ampère, one of the main discoverers of electromagnetism.

Amendment 3: Changes To Consumer Unit Regulations - To read more about Amendment 3 click here