Areas covered under this Category are as follows:
- Cavity Wall
For this Category
NHIC membership comprises many of the most important companies and organisations operating in the home improvement sector - www.nhic.org.uk
Cavity Insulation Guarantee Agency - www.ciga.co.uk
National Insulation Association - www.nationalinsulationassociation.org.uk
The Property Care Association - www.property-care.org
A to B
- Absorption co-efficient: the fraction of incident sound energy that will be absorbed by a given surface.
- Absorption: the process by which sound energy is converted into heat.
- Air infiltration: air ingress into a building through cracks or gaps.
- Airborne sound: sound radiated directly from a noise source into the surrounding air.
- Attic room insulation: you can insulate between the rafters and plasterboard over it.
- Audible range: 20Hz to 20kHz (approximately).
- A-weighting: a frequency weighting network corresponding approximately to the sensitivity of the human ear.
- Blown wool: loose mineral wool insulation applied by blowing, usually into cavity walls or lofts.
C to D
- Conduction: the transmission of heat through, along or from one material to another material in contact with it.
- Convection: the transfer of heat by movement of air.
- Crosstalk: the transfer of sound from one area to another - often used in connection with ducted ventilation systems.
- Damping: a process whereby vibration energy is converted into heat through some form of frictional mechanism.
- Db: decibel - the basic unit of sound - most commonly used to refer to sound pressure level, but can equally refer to sound power level, sound intensity level etc.
- Dewpoint: a calculated temperature at which water vapour will condense.
E to F
- Emissivity: is a measure of the radiation emitted from a surface.
- Fiberisation: the manufacturing process of turining molten raw material (e.g. for insulation; glass or stone) into fibres.
- Flanking transmission: the transmission of sound into an area via an indirect route (e.g. between an upper and lower floor via common walls).
- Flat roof insulation: can be insulated on the outside when re-felting.
- Frequency of sound: is measured in Hz (Hertz).
G to H
- Ground-floor insulation: insulation can be installed under the floor-boards, or under a solid floor, to prevent heat loss. Timber.
- Heat loss: heat transfer from internal spaces to external areas through conduction, convection and radiation.
I to J
- Impact sound: sound transmitted between two areas by direct impact upon the dividing element (e.g. Sound of footsteps on an internal floor).
- Interstitial condensation: is condensation that occurs within a building element. It can be very harmful if interstitial condensation occurs on surfaces within the structure, as this can lead to the rot of timber or oxidation of metal surfaces.
M to N
- Mineral wool: usually comes as a roll, is a fibrous material and is typically laid in attic rooms to improve the insulation of a house i.e. reduces heat loss via the roof of a building.
- Noise reduction coefficient (NRC): a single value for sound absorption, derived as the mean value of 4 frequencies in the range 250-2000Hz.
O to P
- Peak particle velocity (PPV): is the peak level of vibration during an event. This parameter is most commonly used when the maximum level of vibration is to be identified.
- Pitch roof insulation: can be insulated on the outside by lifting the slates or tiles, fixing insulated sarking board to the rafters and fixing the tiles to the board.
Q to R
- Radiation: the process by which heat is emitted from a body through open space, for example, sunlight.
S to T
- Sound absorption: sound energy converted into mechanical vibration energy and/or heat energy. Sound absorption is usually expressed as a sound absorption coefficient.
- Sound insulation: the ability of a building element or building structure to reduce the sound transmission through it.
- Sound strength (dB): measured in dB (decibel). Db is measured at different frequencies.
- Surface resistance: surface resistance (Rs) is the reciprocal of surface coefficient. Its units are m2/K/W.
- Thermal conductivity: the rate at which heat is transmitted through a material, measured in watts per square metre of surface area for a temperature gradient of one kelvin per metre thickness, simplified to W/mK.
- Thermal mass: the mass in a structure which is used to absorb solar heat during the day and then release the heat in the evening.
- Thermal resistivity: resistivity is a measure of a material's thermal resistance and is the reciprocal of its conductivity. It is a measure of the thermal characteristic of a material and is independent of its thickness.
U to V
- Vibration dose value (VDV): is the equivalent level of vibration experienced over a period of time and is the normal parameter used for assessing the impact of vibration on people.