Glossary
Sound Insulation Testing
Impact Sound Test: This test is carried out on the floors (only if applicable to the property). A tapping machine is placed on the floor of the upper of the test rooms and is used as the sound source to measure the noise received in the room below. (Simulating footfall).
Airborne Sound Testing: Initiation of a controlled noise on one side of the wall (or floor) and measuring the pressure level of the sound on the other side. It allows us to calculate the difference between two rooms and to compare the obtained results to the requirements of performance. This provides the result of the airborne sound insulation.
Absorption: Conversion of sound energy to heat, often by the use of a porous material.
Absorption coefficient: A quantity characterising the effectiveness of a sound absorbing surface. The proportion of sound energy absorbed is given as a number between zero (for a fully reflective surface) and one (for a fully absorptive surface). NOTE: Sound absorption coefficients determined from laboratory measurements may have values slightly larger than one. Refer to I.S. EN ISO 354.
Airborne sound: Sound which is propagated from a noise source through the medium of air, e.g. speech and sound from a television.
Airborne sound insulation: Sound insulation that reduces transmission of airborne sound between buildings or parts of buildings.
Air path: A direct or indirect air passage from one side of a structure to the other.
Cavity stop: A proprietary product or material such as mineral wool used to close the gap in a cavity wall to minimise flanking sound transmission along the wall cavity.
Cavity barrier: A construction provided to close a concealed space against penetration of smoke or flame, or provided to restrict the movement of smoke or flame within such a space (refer to TGD B – Fire Safety).
Decibel (dB): The unit used for many acoustic quantities to indicate the level with respect to a reference level.
Density: Mass per unit volume, expressed in kilograms per cubic metre (kg/m3).
Direct transmission: Refers to the path of either airborne or impact sound through elements of construction.
DnT: The difference in sound level between a pair of rooms, in a stated frequency band, corrected for the reverberation time. Refer to I.S. EN ISO 16283-1.
DnT,w: The weighted standardised level difference. A single number quantity (weighted) which characterises the airborne sound insulation between rooms in accordance with I.S. EN ISO 717-1.
Dynamic stiffness: A parameter used to describe the ability of a resilient material or wall tie to transmit vibration. Specimens with high dynamic stiffness (dynamically ‘stiff’) transmit more vibration than specimens with low dynamic stiffness (dynamically ‘soft’). Refer to I.S. EN 29052-1 for resilient materials. See BRE Information Paper IP 3/01 for wall ties.
Flanking element: Any building element that contributes to sound transmission between rooms in a building that is not a separating floor or separating wall.
Flanking transmission: Sound transmitted between rooms via flanking elements instead of directly through separating elements or along any path other than a direct path.
Floating floor: A floating floor consists of a floating layer and resilient layer (see also floating layer and resilient layer).
Floating layer: A surface layer that rests on a resilient layer and is isolated from the base floor and the surrounding walls (see also resilient layer).
Frequency: The number of pressure variations (or cycles) per second that gives a sound its distinctive tone. The unit of frequency is the Hertz (Hz).
Frequency band: A continuous range of frequencies between stated upper and lower limits (see also octave band and one-third octave band).
Hertz (Hz): The unit of frequency of a sound (cycles per second).
Impact sound: Sound resulting from direct impact on a building element.
Impact sound insulation: Sound insulation which reduces impact sound transmission from direct impacts such as footsteps on a building element.
Isolation: The absence of rigid connections between two or more parts of a structure.
L’nT: The impact sound pressure level in a stated frequency band, corrected for the reverberation time. See I.S. EN ISO 140-71.
L’nT,w: The weighted standardised impact sound pressure level. A single-number quantity (weighted) to characterise the impact sound insulation of floors, in accordance with I.S. EN ISO 717-2.
Octave band: A frequency band in which the upper limit of the band is twice the frequency of the lower limit.
One – third octave band: A frequency band in which the upper limit of the band is 21/3 times the frequency of the lower limit.
Rw: A single number quantity (weighted) which characterises the airborne sound insulation of a building element from measurements undertaken in a laboratory, in accordance with I.S. EN ISO 717-1.
Resilient layer: A layer that isolates a floating layer from a base.
Resilient material: A material which returns to its original thickness after it has been compressed.
Resonance: increased amplitude of oscillation of an object when it is subjected to vibration from another source at or near its own natural frequency.
Reverberation: The persistence of sound in a space after a sound source has been stopped.
Reverberation time: The time, in seconds, taken for the sound to decay by 60 dB after a sound source has been stopped.
Sound pressure level: A quantity related to the physical intensity of a sound.
Sound reduction index (R): A quantity, measured in a laboratory, which characterises the sound insulating properties of a material or building element in a stated frequency band. Refer to I.S. EN ISO 101401 to 5.
Spectrum: The composition of a particular sound in terms of separate frequency bands.
Structure-borne sound: Sound which is carried via the structure of a building.
∆Lw: The measured improvement of impact sound insulation resulting from the installation of a floor covering or floating floor on a test floor in a laboratory (See I.S. EN ISO 717-2).
Ventilation Validation
Air permeability: The average volume of air in cubic meters per hour that passes through one square meter of the building envelope when subject to an internal to external pressure difference of 50 Pascals when measured in accordance with the method defined in I.S. EN ISO 9972:2015, Thermal performance of buildings – Determination of air permeability of buildings – Fan pressurization method. It is a measure of the resistance of the building envelope to air infiltration.
Air infiltration: The exchange of air between outside a building and inside other than through openings provided by design (for ventilation, access and other purposes). Infiltration is caused by pressure difference effects of wind and/or stack effect and occurs through cracks, porosity of building elements and other unintentional openings in the building fabric.
Automatic control: Control of a ventilation device, (e.g. opening, switching on or adjusting performance) by mechanical or electronic means in response to a relevant external stimulus, (e.g. humidity, pollutant level, occupancy detection, pressure difference).
Background ventilator: A secure ventilation opening generally located in a wall or window for the purpose of provision of general ventilation, generally incorporating a controllable ventilation grill, which can be fully closed.
Balancing: consists of adjusting the airflow rate through supply and return grills working backwards to the fan in an iterative process from the remote branches, setting the correct proportional airflow at each damper on the system with regards for design flow rates.
Continuous operation: A ventilation system that runs all of the time that ventilation is required, e.g. a mechanical ventilation system as the principal means of general ventilation. The performance level, e.g. airflow rate, may be adjusted manually or by automatic control during operation.
Equivalent area: The area of a single sharp-edged hole that passes the same air volume flow rate at the same applied pressure difference as the vent being tested.
Extract ventilation: Designed provision for the removal of air from a room or space directly to outside. Extract ventilation may be provided by natural means (e.g. passive stack ventilation) or by mechanical means (e.g. by an extract fan).
General ventilation: Ventilation of rooms and spaces at a relatively low continuous rate to control pollutant and water vapour levels to acceptable levels generally and provide adequate levels of fresh outdoor air.
Intermittent operation: Operating when a particular need is identified. Intermittent operation may be in response to automatic control responding to a particular stimulus, or manual control when need is identified by user.
Manual control: Control of a ventilation device, e.g. opening, switching on or adjusting performance, by manual intervention of user, e.g. dwelling.
Passive stack ventilation (PSV): A continuous ventilation system using ducts from high level locations within rooms to terminals on or above the roof, which provides a flow of air by a combination of the natural stack effect, i.e. the movement of air due to the difference in temperature between inside and outside, and the effect of wind passing over the roof of the dwelling.
Permanent ventilator: A ventilator permanently fixed in the open position and not provided with a means of closure, which eliminates airflow through the device.
Purge ventilation: Ventilation by means of a large adjustable ventilation opening or openings, which will allow the movement of a substantial volume of air in a short time period e.g. an opening window or door, and with some part of the ventilation opening at least 1.75 m above the floor level.
Stack effect: Airflow between inside and outside a building due to the pressure differential caused by differences in air density associated with indoor/outdoor air temperature differences.
Ventilation opening: Any means of permanent or controllable ventilation which: – – opens directly to the external air, and – except in the case of a screen, fascia, baffle, etc., has a smallest dimension of at least 8 mm, but does not include a flue to a chimney.
Wet room: A room used for domestic activities, e.g. cooking, clothes washing, bathing, which, by their nature, are likely to give rise to significant production of water vapour. Typical wet rooms in dwellings are kitchens, utility rooms, bathrooms and sanitary facilities containing provision for showering or bathing.
Airtightness Testing
Airtightness: impermeable to air or nearly.
Blower door: A blower door describes the devices used for testing the air permeability of a dwelling. This consists of a calibrated variable speed and controlled fan, an adjustable frame and lastly a manometer.
Manometer: A manometer is a device that is used to measures the pressure of a fluid or gas in a confined space. In the case of airtightness testing it is used to measure the pressure inside and outside the dwelling to determine the difference.
m3/hr/m2: Air changes per hour also known as Npr or air permeability rate. It stands for the amount of air leakage divided by the internal volume of the building. The lower the number the more energy efficient a house is.
Smoke Test: A smoke test is used to identify areas in a building where energy is being lost due to air leakage. This is performed using a device that creates a vapour or fog.
NSAI: National Standards Authority Ireland. Ireland’s official standards body.
CIBSE Technical Manual TM 23 (Testing Buildings for Air Leakage): A technical memorandum containing standards and practices for airtightness testing published by the Chartered Institution of Building Services Engineers.
Cogeneration: means the simultaneous generation in one process of thermal energy and electrical or mechanical energy.
Delivered Energy: Energy supplied to the building and its systems to satisfy the relevant energy uses, e.g. space heating, water heating, cooling, ventilation, lighting. Delivered Energy does not include renewable energy produced on-site. Delivered Energy differs from energy use by the extent of on-site conversion and transformation losses, e.g. boiler efficiency losses.
District Heating or District Cooling: means the distribution of thermal energy in the form of steam, hot water or chilled liquids, from central or decentralised sources of production through a network to multiple buildings or sites, for the use of space or process heating or cooling.
Efficient District Heating and cooling: a district heating or cooling system using at least 50 % renewable energy, 50 % waste heat, 75 % cogenerated heat or 50 % of a combination of such energy and heat.
Heat Generator: means the part of a heating system that generates useful heat using one or more of the following processes: (a) the combustion of fuels in, for example, a boiler; (b) the Joule effect, taking place in the heating elements of an electric resistance heating system; (c) capturing heat from ambient air, ventilation exhaust air, or a water or ground heat source using a heat pump.
Heat Pump: is an encased assembly or assemblies designed as a unit, using a vapour compression cycle or gas absorption cycle to provide the delivery of heat.
Nearly Zero-Energy Building (NZEB): means a building that has a very high energy performance, as determined in accordance with Annex I of the EU Energy Performance of Buildings Directive Recast (EPBD Recast) 2010/31/EU of 19th May 2010. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced onsite or nearby.
Primary Energy: means energy from renewable and non-renewable sources which has not undergone any conversion or transformation process.
Renewable Energy: Energy from renewable non-fossil energy sources, e.g. solar energy (thermal and photovoltaic), wind, hydropower, biomass, geothermal, ambient energy, wave, tidal, landfill gas, sewage treatment plant gas and biogases.
Seasonal Efficiency: The seasonal efficiency should be calculated as defined in DEAP.
Seasonal Space Heating Energy Efficiency: means the ratio between the space heating demand for a designated heating season, supplied by a heater and the annual energy consumption required to meet this demand, expressed in %.