Whereas a conventional chiller uses a compressor to raise the pressure (and temperature) of refrigerant in the refrigeration cycle, an absorption chiller uses heat (typically from a CHP system).
A projecting structure, or wing, which is part of the original building rather than a subsequent extension.
Pebbles, shingle, gravel etc. used in the manufacture of concrete, and other construction work.
AHUs maintain adequate ventilation by providing fresh, filtered outside air and delivering it at the condition required to the internal space. AHUs can be used to control the temperature and humidity of the air.
These use external ambient air as a heat absorption/rejection medium for the heat pump. They are cheaper and easier to install than some other heat pump systems but are subject to outside air temperature fluctuations and are vulnerable to possible physical damage.
A perforated brick built into a wall for providing ventilation. Used, for instance, to ventilate the underside of timber ground floors, blocked fireplaces or a roof space.
Regulating dampers direct to the air flow to either the heating or the cooling exchanger coil.
A row of arches supported by columns.
A section above a door or opening window with the structural function of dispersing the weight from above around the opening. Also referred to as a head above a door or window. The shape will determine its name; most common are segmental (semi-circular), lancet (pointed) and gauged (composed of shaped bricks).
In Classical architecture, the lower part of a moulded cornice. Commonly used term for the moulded surround of a door or window.
The sharp external edge where two surfaces meet at a point.
An artistic movement of the turn of the century characterised by stylised forms of flowers and animals, prevalent in Edwardian buildings.
Derived from an artistic movement of the late C19, based on the ideas of William Morris, which promoted traditional forms of design and the use of craft techniques in construction. Its architectural expression is seen in the use of traditional materials and restrained vernacular decoration.
Material used in the past for insulation and fire protection. Can be a health hazard. Specialist advice should be sought if asbestos is found. (ACM = Asbestos Containing Material).
Cement mixed with up to 15% asbestos fibre as reinforcement. Typically used in roofing, rainwater goods, fire-proof linings and various other claddings and linings. It is fragile and will not usually bear heavy weights. Hazardous fibres may be released if cut or drilled.
Finely dressed natural stone: the best grade of masonry.
Black, tar-like substance, designed to be impervious to moisture. Used on flat roofs and floors.
These operate at atmospheric conditions without a fan or pressurisation and are one single unit. The air/fuel mix is controlled by gas flow drawing the air for combustion. Generally, atmospheric boilers will operate in either 'on/off' or 'high/low' settings and cannot modulate.
A window style where the windows open by way of hinges affixed at the top (also called simply top opener).