NATURAL AND ENERGY-EFFICIENT VENTILATION SYSTEMS FOR DOMESTIC BUILDINGS

Transcription

1 CI/SfB (57) Uniclass L753 November 2007 NATURAL AND ENERGY-EFFICIENT VENTILATION SYSTEMS FOR DOMESTIC BUILDINGS

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3 CONTENTS INTRODUCTION 4-5 Passivent systems, Technical context 6-8 EXTRACT VENTILATION SYSTEMS 9-10 Passive Stack Ventilation (PSV) PSV Whole-House 12 PSV Single-Stack 13 PSV Design and Installation Mechanical Extract Ventilation (MEV) Passivent MEV 18 Passivent imev 19 Passivent AV Passivent Flair Positive Input Ventilation (PIV) BACKGROUND VENTILATION Window vents Fresh wall vents ACOUSTIC VENTILATION 45 Acoustic solutions: Systems Acoustic solutions: Background ventilation COMBUSTION AIR VENTILATION COMPONENTS, SERVICES 57 Selected components Design and support, Services References

4 . PASSIVENT the..... natural and..... energy-efficient ventilation specialists Passivent Limited are the leading specialists in natural and energy-efficient mechanical extract ventilation for domestic buildings. Expertise Passivent have an unrivalled expertise in designing and developing ventilation solutions to meet the most up-to-date technical and regulatory requirements. Immense experience During the last 15 years over Passivent systems have been installed in the UK alone, giving efficient and effective ventilation at all times. There is also a vast range of experience with Passivent systems over many years in Europe. Technical and design capability We can provide authoritative technical support, advice and design services. Comprehensive range The Passivent range provides ventilation systems and products tailored to all types of domestic applications. Energy-efficient Passivent systems are extremely energyefficient, typically providing higher energy ratings than other forms of ventilation. They offer many advantages over other, non-responsive, systems. Building regulations compliance Passivent systems can be used to meet building regulations requirements throughout the UK and Ireland. Innovation We are constantly developing our ventilation systems and components to meet new requirements and further improve performance. Quality assurance All Passivent systems and components have been designed, developed and manufactured under a BS EN ISO 9001 Quality Management System. Independent auditing provides the user with assurance that the products will fulfil their intended purpose

5 PASSIVENT SYSTEMS OVERVIEW Passivent offer a range of passive and mechanical extract ventilation systems which meet the requirements for dwellings set out in Building Regulations Approved Document F (England and Wales), and similar requirements for the whole of the UK and the Republic of Ireland. For more details of Building Regulations requirements see page 8. Passivent BBA Certificated PSV and MEV Whole-House systems provide the required functions of: - extract ventilation to remove pollutants, and - whole building (background) ventilation to provide a supply of fresh air These systems have major advantages over ventilation based on individual extract fans. Passivent window/wall ventilators can provide whole-building (background) ventilation for Intermittent Fan (System1) and Continuous Mechanical Extract (System 3) systems by others. Positive Input Ventilation (PIV) is an alternative strategy which is acceptable under Approved Document F provided compliance can be demonstrated

6 NATURAL AND ENERGY-EFFICIENT VENTILATION FOR DOMESTIC BUILDINGS PASSIVENT SYSTEMS Passive Stack Ventilation (PSV) see pages (Approved Document F System 2) Applications: Main features: Public and private housing, primarily for individual houses and flats. New-build, major refurbishment Continuous demand controlled ventilation, silent operation, no energy consumed Mechanical Extract Ventilation (MEV) see pages (Approved Document F System 3) Applications: Main features: Public and private housing. Houses, flats, multi-occupancy buildings such as nursing homes, student accommodation, hotels. New-build, major or minor refurbishment Single central fan connected to multiple extracts, continuous low-level ventilation, quiet operation Positive Input Ventilation (PIV) see pages (Approved Document F paragraph 0.15) Applications: Main features: Public and private housing. Houses, flats. Major or minor refurbishment Ductless system, easy to install. Background Ventilation see pages (Approved Document F Systems 1, 2 and 3) Applications: Main features: Public and private housing. Houses, flats, multioccupancy buildings such as nursing homes, student accommodation, hotels. Major or minor refurbishment Large range of controllable window and throughwall vents. Acoustic Ventilation see pages (Approved Document F Systems 1, 2 and 3) Applications: Main features: All types of housing in areas of high noise levels PSV, MEV and background ventilation with acoustic treatment for sound reduction

7 NATURAL AND ENERGY-EFFICIENT VENTILATION FOR DOMESTIC BUILDINGS TECHNICAL CONTEXT Why ventilate Ventilation is essential in all buildings for the well-being and health of the occupants to: Provide a supply of fresh air for persons using the building, creating a comfortable environment. Extract moisture at source from areas where it is produced in significant quantities (eg kitchens and bathrooms), thereby combating condensation. Dilute and remove pollutants including dust mites, tobacco smoke and cleaning chemicals, promoting a healthier air quality. Aid the removal of occasional high concentrations of pollutants and water vapour. Ventilation may also be used to improve thermal comfort and reduce overheating of buildings in summer. Energy savings Buildings are being made more and more airtight, driven by government regulations to save energy and reduce carbon emissions. Previous fortuitous ventilation routes (by natural infiltration) are being sealed, increasing the importance of an effective ventilation strategy. The need to reduce energy consumption and combat climate change means that energy savings must be made in buildings. It is therefore vital to select an effective and energy-efficient method of ventilation. Passivent systems are proven to be among the most energy-efficient. Energy efficiency and SAP Government action in response to climate change is driving the demand for increased energy efficiency. By 2016 the Government wants all new dwellings built to be zerocarbon. As part of building regulations improvements, all new housing has to be energy rated; this is achieved through the Standard Assessment Procedure (SAP). Passivent PSV with no electrical consumption and automatic operation is naturally energy-efficient. To allow flexibility and encourage innovation, energy-efficient systems can be independently tested and their actual performance used in the SAP through the Appendix Q route instead of the SAP default value. The use of energy-efficient DC fans in all Passivent MEV systems makes them more energy efficient than the SAP MEV default value. Health benefits Proper ventilation of buildings has been shown to help reduce the incidence of asthma and other allergy related problems. Controlled ventilation Traditional buildings had a considerable amount of accidental ventilation through air infiltration. In order to reduce energy loss, modern buildings (and refurbished buildings) are increasingly required to meet standards for reduced air leakage. By itself, this would lead to problems arising from lack of ventilation. A ventilation strategy is therefore required to provide good indoor air quality whilst minimising energy loss through unintended air leakage. The concept of 'build tight - ventilate right' means: - Minimising the amount of accidental and uncontrolled air leakage through the building envelope - Providing controlled ventilation to supply the required level of fresh air and expel moisture vapour and other air pollutants. In other words, ventilation where and when it is needed

8 NATURAL AND ENERGY-EFFICIENT VENTILATION FOR DOMESTIC BUILDINGS TECHNICAL CONTEXT Ventilation design A designed ventilation strategy should make use of the following elements: Extract ventilation from 'wet' rooms including kitchens, bathrooms, utility rooms and WCs, to remove water vapour, together with other pollutants, directly from the rooms where it is mostly generated. Whole building ventilation to provide a supply of fresh air from outside. This also has the function of diluting and dispersing pollutants wherever they are generated within the building. Purge ventilation to remove high concentrations of pollutants generated by occasional activities such as painting and decorating. Building Regulations requirements The basic requirement of regulations is that there should be adequate means of ventilation for the occupants of a building. Requirements, and detailed means of satisfying them, are given in the documents listed below. Passivent Technical Services Team can also provide advice and guidance on ventilation and regulatory compliance. England and Wales Approved Document F Means of ventilation (2006). For guidance, please refer to: Scotland Building (Scotland) Regulations 2004, Technical Handbook Domestic Section 3 Environment (2007). Northern Ireland Building Regulations (Northern Ireland) Technical Booklet K Ventilation (1998). Republic of Ireland Building Regulations Technical Guidance Documents, Part F Ventilation (2002). Associated regulations The building regulations for energy conservation also require control of air leakage rates through the building fabric (England and Wales Part L) and provision of an air supply for fuel-burning appliances (combustion air, England and Wales Part J)

9 EXTRACT VENTILATION SYSTEMS Passive Stack Ventilation (PSV) PSV Whole-House 12 PSV Single-Stack 13 Mechanical Extract Ventilation (MEV) Passivent MEV 18 Passivent imev 19 Passivent AV Passivent Flair Positive Input Ventilation (PIV)

10 EXTRACT VENTILATION SYSTEMS PASSIVENT SYSTEMS Passivent have ventilation systems tailored for all types of domestic applications and to meet the requirements of building regulations. Passive Stack Ventilation (PSV) see pages (System 2) Applications: Public and private housing, primarily for individual houses and flats. New-build, major refurbishment Main features: Continuous demand controlled ventilation, silent operation, no energy consumed Mechanical Extract Ventilation (MEV) see pages (System 3) Applications: Public and private housing. Houses, flats, multi-occupancy buildings such as nursing homes, student accommodation, hotels. New-build, major or minor refurbishment Main features: Single central fan connected to multiple extracts, continuous low-level ventilation, quiet operation Positive Input Ventilation (PIV) see pages Applications: Public and private housing. Houses, flats. Major or minor refurbishment Main features: Ductless system, easy to install

11 EXTRACT VENTILATION SYSTEMS PASSIVE STACK VENTILATION (PSV) PASSIVE STACK VENTILATION (PSV) System 2 The PSV principle Passive stack ventilation (PSV) is driven primarily by the natural stack or convection effect by which warm air rises. Moisture-laden air is extracted directly from wet rooms (kitchens, bathrooms etc) through ducting up to a roof terminal where it is vented to the outside. The air inside a house is almost always warmer than that outside, and so rises up the duct by natural convection, carrying moisture with it. Wind blowing across the roof provides additional suction (the venturi effect). Colder air outside Moisture-laden warm air rises up duct and is exhausted through roof terminal Warm moist air inside

12 EXTRACT VENTILATION SYSTEMS PASSIVE STACK VENTILATION (PSV) PSV WHOLE-HOUSE A PSV Whole-House system ventilates all the rooms in a property effectively, using the concept of planned air routes to ensure a fresh healthy environment. Planned air routes Moisture is extracted at source from wet rooms (kitchens, bathrooms etc). Air inlets located in dry rooms (living rooms, bedrooms etc) provide a flow of replacement fresh air into the building. The siting of the inlets and extracts ensures that air always moves from dry rooms to wet rooms, so that moisture is removed and the whole house is ventilated. Applications Suitable for both new-build and refurbishment in private and social housing. Primarily designed for individual houses and low-rise flats and apartments. Demand control Ventilation is controlled by intelligent inlets and extracts which respond automatically to changes in relative humidity, thereby modulating the ventilation rate in each room to meet demand. When humidity is low the ventilation rate is minimised, irrespective of external weather conditions, preventing unnecessary heat loss. Both inlets and extracts are operated by a set of nylon strands which respond to humidity levels and regulate the size of the air opening, giving greater ventilation when humidity is high whilst preventing unnecessary ventilation when humidity is low. Features and benefits Natural and energy-efficient No electrical connection or power source is required, so Passivent PSV systems are naturally energy-efficient. Continuous operation The system provides 24-hour condensation control with continuous gentle extraction. It operates all day and every day as required, combating condensation and mould growth. Reduces requirement for background ventilation Using PSV means fewer tricklevents or wall vents are required, when compared to using intermittent fans. No noise Passivent PSV systems are completely silent in operation. Ideal for special needs With its automatic response and no operating controls, Passivent PSV is ideal for special-needs applications. Minimal maintenance No mechanical components to go wrong. BBA approved Passivent PSV Whole-House systems are covered by BBA (British Board of Agrément) Certificate No 96/3273. Design service Passivent Limited offers a design service for PSV systems, see over. Typical PSV Whole-House ventilation system All air inlets and extracts respond automatically to relative humidity in rooms. Air movement is from dry to wet rooms. Building regulations Passivent systems can be used to satisfy building regulations requirements throughout the UK and the Republic of Ireland for extract and whole-house ventilation for domestic and domestic-type properties See also the general introduction page 8. More information is available on request. Passivent systems also meet the regulatory requirements for security, avoiding draughts and preventing rain ingress. Separate roof terminal for each stack Bedroom with air inlet Bathroom with air extract Living room with air inlet Kitchen with air extract

13 PSV SINGLE-STACK As a quiet alternative to an individual room extract fan, PSV Single-Stack systems can be installed to ventilate individual en-suites or bathrooms. They operate by the same natural stack effect as PSV Whole-House systems, and hence represent a superior alternative to a fan. They provide the same benefits of demand control, continuous operation and energy efficiency as PSV Whole-House systems, and are easy to install. Applications Suitable for both new-build and refurbishment in private and social housing. Particularly useful as a low-cost refurbishment installation in social housing. Typical PSV Single-Stack system Extract responds automatically to relative humidity. Roof terminal Individual or en-suite bathroom with air extract

14 EXTRACT VENTILATION SYSTEMS PASSIVE STACK VENTILATION (PSV) SYSTEM DESIGN AND INSTALLATION Design of a system for an individual property is quite simple using our online design and quotation web site at Alternatively Passivent Limited offers a design service for PSV systems, based on building drawings supplied. A full installation guide is supplied with every Passivent PSV system. Typical layout (schematic) Actual installations may differ in detail. Follow the design layout if one is provided. Terminals must be no more than 0.5 metre down from the ridge. Each duct must run to a separate terminal Ducts must rise vertically or near-vertically, preferably not more than 45 from vertical with a maximum of 2 no. bends Use insulated ducting in the roof void and other unheated spaces The main features of a typical installation with the points which must be observed are shown below. For simplicity of design and ordering, a number of standard stack kits are available. Ordering To order Passivent-designed PSV systems simply state the quotation number and plot or plots required followed by the ridge or tile manufacturer, make and colour. For selfdesigned PSV systems simply quote the stack kit reference and quantity of each required, followed by the ridge or tile manufacturer, make and colour, and the inlet type and quantity required. Support flexible ducting every 300mm to a wire or timber batten to prevent sagging System components Standard stack kits are available as shown. Where these are not suitable, alternative configurations can be supplied. Extension ducting is also available for properties over two storeys. For individual components (air inlets, terminals, ducting) see the Components section page 58. Code A161 Description Humidity-sensitive extract F12513 Uninsulated flexible ducting, 3.0m F12524 Insulated flexible ducting, 4.0m FCA3 FCA4 FCA6 FCA10 FCA11 Flat channel straight connector Flat channel circular connector Flat channel circular adaptor Flat channel elbow connector Round pipe FCD1 Flat channel ducting, 1.5m MC01 PRT TT7 TT9 Sleeve coupling, male 125mm Ridge terminal In-Line tile/slate terminal Tile terminal Speed clamp Bedroom Site air inlets in dry rooms (living rooms, bedrooms etc) Bathroom Site each air extract in a wet room (kitchen, bathroom) Within the building, run circular ducting in a room corner or inside a fitted cupboard or wardrobe. Alternatively run flat channel ducting within a stud partition Air flow from dry to wet rooms Living room Kitchen There is usually sufficient air flow around internal doors to provide replacement air. If this is insufficient a door undercut of 10mm or an air transfer door grille should be used. No electrical connections are required

15 PSV 01 Kit Typical ground floor kitchen: Flat ducting, ridge terminal. PRT F12524 FCA4 FCA6 FCD1 FCA3 FCD1 FCA6 A161 PSV 05 Kit Typical first floor bathroom: Ridge terminal. PRT F12524 A161 PSV 06 Kit Typical first floor bathroom: Tile terminal. TT9 F12524 A161 PSV 02 Kit Typical ground floor kitchen: Circular ducting, ridge terminal. PRT F12524 A161 PSV 03 Kit Typical ground floor kitchen: Circular ducting, tile terminal. MC01 F12513 PSV 07 Kit Typical ground floor kitchen: Wall extract, flat ducting, tile terminal. TT9 F12524 FCA4 FCA6 FCD1 FCA3 FCD1 FCA10 A161 FCA11 TT9 F12524 MC01 F12513 A161 PSV 08 Kit Typical ground floor kitchen: Flat ducting, tile terminal. TT9 F12524 FCA4 FCA6 FCD1 FCA3 FCD1 FCA6 A161 PSV 04 Kit Typical ground floor kitchen: Wall extract, flat ducting, ridge terminal. PRT F12524 FCA4 FCA6 FCD1 FCA3 FCD1 FCA10 A161 PSV 09 Kit FCA11 Typical first floor bathroom: In-Line tile/slate terminal. Not suitable for kitchens. TT7 F12524 A161 Specification clause Select options required, and insert information where necessary. Passivent PSV Whole- House ventilation system Provide a BBA-Certificated ventilation system complying with Building Regulations (England and Wales) Approved Document F OR Building (Scotland) Regulations Technical Handbook Domestic Section 3 OR Building Regulations (Northern Ireland) Technical Booklet K OR Building Regulations (Republic of Ireland) Technical Guidance Documents Part F, by means of a whole-house passive stack ventilation (PSV) automatic system comprising: Humidity-sensitive wall/window inlet vents operating between 47% and 65% relative humidity, sited in habitable rooms as required. Humiditysensitive ceiling extracts operating between 30% and 75% relative humidity sited in kitchen, bathroom, utility room and WC; each extract to be ducted separately to a roof terminal matching and forming an integral part of the ridge, or to pitched roof tile/slate terminals sited no lower than 0.5 metres down from the ridge. Ridge terminals to have an air flow resistance not exceeding 10Pa at an air movement rate of 100m 2 /h. Tile/slate terminals to have an air flow resistance not exceeding 5Pa at an air movement rate of 100m 2 /h. All terminals to provide insect and weather protection, and be designed to ensure any condensate forming will run off on to the roof. All ducting in roof spaces and other unheated spaces to be fully insulated with 25mm insulation. The system to be Passivent PSV Whole-House system covered by BBA Certificate 96/3273, supplied by Passivent Limited, 2 Brooklands Road, Sale, Cheshire M33 3SS. Telephone: , fax: , info@passivent.com. Installation to be in accordance with the manufacturer s instructions, and to be carried out by a Passivent Mastercare trained installer holding a current certificate. Layout and installation must comply with any design recommendations supplied

16 EXTRACT VENTILATION SYSTEMS MECHANICAL EXTRACT VENTILATION (MEV) MECHANICAL EXTRACT VENTILATION (MEV) System 3 Passivent MEV systems Passivent Mechanical Extract Ventilation (MEV) systems provide continuous mechanical extraction at a low rate, boostable (manually or automatically) to extract at a higher rate when required. Whole-house systems comprise a remotely located central extract fan connected by ducting to extracts in wet rooms (kitchen, bathrooms etc), with air inlets located in dry rooms only (eg living rooms, dining rooms, bedrooms). Planned air paths Moisture is extracted at source from wet rooms. Air inlets located in dry rooms provide a flow of replacement fresh air into the building. The siting of the inlets and extracts ensures that air always moves from dry rooms to wet rooms, so that moisture and other pollutants are removed at source and the whole building is ventilated. MEV Systems Passivent has a range of MEV systems which can be matched to the intended application. Passivent MEV Continuous extract system with boost, automatic or manual, provided by extracts. Primarily individual systems for houses and apartments. Passivent imev Continuous extract system with boost provided by automatic humidity-sensitive control of fan speed and extracts. Provides individual room control automatically. Passivent AV Continuous extract system with boost, automatic or manual, provided by extracts. Primarily multiple systems for apartments and multi-occupancy applications. Passivent Flair Continuous extract system for new-build apartments, integrating the latest design in cooker hoods. Air is exhausted through roof (or wall) terminals Low-power continuouslyrunning central extract fan located in loft space (or cupboard) Air extracts located in wet rooms Extract ducts may serve a number of rooms

17 Applications MEV systems are suitable for a wide range of applications including houses, apartments and multi-occupancy buildings such as nursing homes, student accommodation and hotels. In flats and apartments MEV systems can be designed to ventilate either an individual apartment or several apartments simultaneously. Systems are suitable for both new build and refurbishment. Features and benefits Tailored systems The range of extracts enables systems to be tailored specifically to suit individual room applications. Demand control Humidity-sensitive system, with automatic boost to meet greater demand when required, provides greater comfort and energy efficiency. Planned air movement The positions of inlets and extracts ensure that air always moves from dry rooms to wet rooms, where it is extracted. Continuous extraction with boost Continuous gentle extraction at all times; the system operates all day and every day, boosting as required. No noise problems The fan is normally installed in the roof space or a cupboard to avoid noise problems. Ideal for special needs Automatic imev option ideal for special needs, with no manual control required. Energy-efficient, low maintenance Fans have a low energy consumption, and minimal maintenance is required. Simple installation Requirement for background ventilation (air inlets) is significantly reduced compared with intermittent extract fans. Design service Passivent Limited offer a design service for MEV systems. Building Regulations and energy performance The Government s Standard Assessment Procedure (SAP) is the method for calculating the energy rating or performance of dwellings to comply with Building Regulations. Registered SAP assessors use a computer program to calculate - the SAP rating - the Target CO 2 Emission Rate (TER) based on standard values for a dwelling of the same size and shape, and - the Dwelling CO 2 Emission Rate (DER), based on the performance values for the actual dwelling being assessed. For compliance, the DER must be no worse than the TER. Appendix Q of the SAP allows the use of actual performance data derived from independent assessments of systems, in place of default values. For energy efficient systems such as Passivent MEV this method can provide an enhanced SAP rating. The A151DC fan used in the Passivent MEV system is included on the Appendix Q web site. System design Passivent offer a design service for our MEV systems, based on building drawings supplied. Initially an outline proposal and estimate for a system will be prepared; following acceptance of this, a full design and costing will be prepared. System installation A full installation guide is supplied with each mechanical extract ventilation system

18 EXTRACT VENTILATION SYSTEMS PASSIVENT MEV Description Extraction is driven by a single low-power consumption DC fan. This is normally installed in the roof space or a cupboard and mounted to avoid noise disturbance. Fans operate efficiently at all times whether vents are fully open or virtually closed. Extraction can be boosted by a control switch, which shows the user via an LED display, the level at which the fan is operating. BBA approved Passivent MEV Whole-House systems are covered by BBA (British Board of Agrément) Certificate No 96/3273. System components Extract fan A151DC Low-wattage DC continuously-running fan, specially designed for efficient extraction of air along lengthy ducts. Extract A125 extracts located in wet rooms. Other components For air inlets, terminals, and ducting, see the Components section on page 58. System installation A full installation guide is supplied with each system. Typical MEV Whole-House ventilation systems Air movement is from dry to wet rooms Individual house Apartments: individual systems Extract fan Extract fan Bathroom Extract fan Kitchen Bathroom Kitchen Kitchen Bathroom

19 EXTRACT VENTILATION SYSTEMS PASSIVENT imev Description Innovative and intelligent, imev is a totally new concept in central mechanical extract ventilation. The system automatically provides, without any occupant involvement, individual room control, and is eminently suitable for both houses and apartments. The low-energy DC central extract fan incorporates a humidity sensor linked to a microprocessor that continuously monitors the relative humidity of the extracted air. The fan is linked via ducting to humidity responsive extracts located in the wet rooms. These open and close in response to relative humidity. Sensing increasing humidity the processor will progressively boost the fan. Therefore when relative humidity increases in that room: 1. the extract in that room will open 2. the humidity of the exhaust air will increase 3. the fan speed will increase 4. thus boosting the extract rate from the room containing the open extract. As humidity is reduced the extract will close and the fan will slow down to its normal running setting, until relative humidity in a wet room increases again. System components Extract fan A151DCH Low energy central extract fan containing integral humidity sensor and microprocessor. Progressively boosts extract rate in response to increasing levels of relative humidity in the extracted air. Extracts A121 humidity sensitive extracts located in wet rooms respond automatically to changes in relative humidity, opening and closing to meet demand, working in harmony with the fan to boost individual room extraction. Other components For air inlets, terminals, and ducting, see the Components section on page 58. System installation A full installation guide is supplied with each system. Typical imev Whole-House ventilation systems Individual house Apartments: individual systems Extract fan Extract fan Bathroom Kitchen Bathroom Extract fan Kitchen Kitchen Bathroom

20 EXTRACT VENTILATION SYSTEMS PASSIVENT AV Description Extraction ventilation is driven by a continuously-running central DC extract fan connected to extracts located in the wet rooms. Ventilation is boosted by the wider opening of the extracts, which can provide either automatic or manual boosts. Passivent AV is eminently suitable for apartments, where a single system can ventilate several apartments, and for student accommodation, hotels and care and nursing homes. Typical AV Whole-House ventilation systems Apartments: multiple system Extract fan Kitchen Bathroom 20 The system is specially designed for efficient extraction of low volumes of air along lengthy ducts. The use of one system for several dwellings can reduce running costs and energy consumption per dwelling. It also minimises the number of roof penetrations required. BBA approved Passivent AV Whole-House systems are covered by BBA (British Board of Agrément) Certificate No 96/3273. System components Extract fan A151DC Low-wattage DC central extract fan for efficient extraction of air along lengthy duct runs. Extracts All extracts are for ceiling or wall-mounting in wet rooms. Boost is provided by wider opening of the vents, controlled as shown below. Humidity-sensitive extracts respond to room humidity automatically. Timed electrical boost is activated manually and operates for a preset time. Constant volume extracts are selfregulating to maintain a constant extract rate. PIR (passive infrared) boost is activated when a person is detected in the room, and operates for a preset time. The range of extracts enables the whole design and ventilation strategy to be tailored to individual room requirements and use. Other components For air inlets, terminals, ducting, see the Components section page 58. Multi-occupancy: nursing homes, student accomodation, hotels etc Bedroom Bedroom Kitchen Extract fan Ensuite bathroom Ensuite bathroom Bathroom Corridor Corridor