the importance of natural ventilation and daylight in schools€¦ · 4 it eputation and helps one...

The importance of Natural Ventilation and Daylight in Schools

ContentsPage 3 Preface

Page 4 Front cover story

Page 5 Haute Vallée, Jersey

Page 6 Introduction

Page 7 The Regulations

Page 8 Queensmead Primary School

Page 9 Seaside School, Lancing

Page 10 Legislative Requirements

Page 11 ‘Building Schools for the Future’

Page 12Addey & Stanhope School

(Acoustic Matters)

Page 13 Imperial College, London

Page 14 CABE

Page 15 BREEAM

Page 16Kidderminster College and Tranent North Primary School

Page 17 Peckham Academy

Page 18 DCSF School Building Bulletins

Page 19 What the papers say!

0 St Joseph’ School, Ipswich

Page 21 Bespoke Windcatcher Systems

Page 22 Air Quality in Schools

Page 23 Reducing CO2

Page 24 Penryn College, Cornwall

Page 25 Cranbrook Primary School

Page 26 Winter Heat Loss

Page 27 Natural Ventilation for Cooling

Page 28 Hazeley School, Milton Keynes

Page 29 Sir William Ramsey School

Page 30 Natural Daylighting - The Problem

Page 31 Natural Daylighting - The Solution

Page 32 Trinity & St Nicholas Schools

Page 33 Jack Tizzard School, London

Page 34 SunPipe and It’s Benefits

Page 35 The Health Benefits of SunPipes

Page 36 The British School, Abu Dhabi

Page 37 Schools in Dubai

Page 38 BRE Testing

Page 39 R&D - Our Commitment

3

There have been a number of Government initiatives over the last few years setting out a comprehensive Design Guide and Legislative

Control over new school building. The ‘Building Schools for the Future’ programme has been heralded as a great success, as has the Academy School building programme, the budget for which has been greatly increased recently. BB 101 which is the definitive document for the design of ventilation for schools is produced by the Department for Children, Schools and Families is regarded as the essential tool and has been the central platform for school design. It is recognised that there have been many further developments in guidelines, as set out in this document.

To minimise carbon emissions and ensure energy efficiency there is strong emphasis on providing schools with natural ventilation, daylighting and passive cooling. Monodraught has a long established record of maximising the use of natural ventilation and daylighting in a wide range of buildings including schools. Monodraught recognise that to ensure successful solutions it is necessary to follow the relevant legislation, guidance documents and certification schemes that contribute to defining an exemplar low carbon school. This recognises not only considering air quality and lighting but also health, noise levels and thermal comfort. Monodraught believe they can make a major contribution to this ultimate goal. This Guide provides an outline of the relevant

requirements and also explains how Monodraught products fulfil these needs. This document is supported by Case Study examples to show how schools have benefited from the technologies developed by Monodraught.

This booklet has been prepared by Monodraught together with the valuable assistance of Dr Martin Liddament of Veetech Ltd and other interested groups to explain the relationship between these various requirements together with clarification, explanations and recommendations on each sector.

Monodraught originally founded by Professor Terry Payne in 1974 has been at the forefront of low energy innovative solutions whose range continues to be the high level of Architectural design empathy achieved through designing flexibility. This enables designs to be visually appealing whilst still achieving an efficient and practical contribution to the harnessing of our natural resources.

The provision of natural daylight by use of SunPipes have been widely used in schools since their launch in 1995, eliminating the need for electric lighting during daytime use and providing the ideal alternative to rooflights and skylights as an energy free natural lighting system. SunPipes projecting natural daylight provide a soothing, calming influence on children, reducing stress and eye strain.

The importance of Natural Ventilation and Daylight in SchoolsA review of current legislation, latest guidelines and example case studies

Preface

The principle of encapsulating any prevailing winds and using this natural resource as a form of ventilation originated some 2,000 years ago in the Middle East, where "wind towers" were often a common sight, but the principle is still used today.

The Monodraught Windcatcher is an extension of that principle but is also a development of the highly successful Monodraught Vertical Balanced-Flue System patented in 1965 which has now been utilised by almost all leading companies in the UK to provide the optimum ventilation system.

February 2009

4

“Reducing energy use makes perfect business sense; it

saves money, enhances corporate reputation and helps

everyone in the fight against climate change ”

Case Study

Front Cover Story

Oxley Park Combined School Milton KeynesArchitect: Architecture MKIt is most appropriate that Milton Keynes Development Corporation have been one of the first to recognise the advantages of natural ventilation and indeed, natural lighting from SunPipes for the benefit of children’s health and development. To date 16 schools in the Milton Keynes area have now been completed using these systems. Architects like the clean lines of the Monodraught systems but also recognise they are making a major contribution to reducing energy costs and maintenance costs in their school budget programme.

The Carbon Trust state in their publication CTG005 Technology guide:-

“Take advantage of natural ventilation and free cooling

and you could halve your energy costs”

“Comfort cooling is very expensive. In the UK, there

are very few days per year where the temperature is

very high (over 28°). Using comfort cooling for just this

short term can cost as much as a whole year’s heating ”

5Case Study

Haute Vallée School St Helier, Jersey

Architect: Architecture PLB, WinchesterThis was one of the first major Projects for Monodraught Windcatchers completed more than 10 years ago in January 1998. Building Simulation carried out extensive modelling and top Environmental Consultants, Battle McCarthy undertook the original design concepts.

This was a new £12 million school, at the time the largest Contract being undertaken in Jersey and demonstrates how classrooms both on the top and ground floor can be served by the Monodraught systems ducted down through the first floor classrooms. The project shows that a particularly striking application of natural ventilation systems can be achieved with a totally energy free use of natural ventilation operating under extreme conditions due to the extensive use of full height glazing.

Monodraught Windcatchers and SunPipes are ideal products for the ‘Quiet Room’, where windows are undesirable since they present a distraction to the child and yet, fresh air and natural sunlight are ideal in providing a quiet, soothing environment.

6

Introduction to the technical aspects of this document

Good ventilation, lighting and thermal comfort are established as being essential requirements for achieving optimum performance and productivity in the classroom. Recent research has shown that inadequate ventilation rates result in increased levels of respirable illness and reduced productivity especially in relation to learning tasks. School designers and specifiers are required to satisfy stringent standards for the school environment. They are also now required to meet tough targets for sustainability.

The UK Government embarked on a major new school building and school refurbishment initiative, covered by the Building Schools for the Future Programme for secondary schools and the Primary Capital Programme for primary schools (see page 11). Specific requirements include:

o Reduced carbon emissions of at least 60% compared to those schools constructed in 2002;

o Zero carbon schools by 2016;

o A BREEAM Rating of at least ‘Very Good’

Strong management and design structures have been established to ensure the goals of sustainability and quality are achieved. This is supported through official design guidance and a range of compliance schemes.

To minimise carbon emissions and ensure energy efficiency there is strong emphasis on providing schools with natural ventilation, daylighting and passive cooling. Designers are thus required to demonstrate that new designs and major refurbishments take full advantage of natural solutions.

To ensure successful solutions it is necessary to follow the relevant legislation, guidance documents and certification

schemes that contribute to defining an exemplar low carbon school. This requires not only considering air quality and lighting but also health, noise levels and thermal comfort. This guide provides an outline of the relevant requirements and presents case study examples to show how all schools can benefit from modern technology.

StructureThe design and refurbishment of schools is covered by an integrated management structure. This incorporates legislative requirements, compliance certification schemes and formal guides. There are also various energy management initiatives aimed at teachers and pupils. The structure relating to the school design process is summarised in the adjacent chart. These items are discussed in further detail in this document.

Organisational ManagementSeveral Government established organisations are responsible for the health, air quality and environmental performance for schools. These include:

z Department for Children Schools and Families (DCSF): This is the Government Department with overall responsibility for schools.

z Partnership for Schools (PfS): Partnerships for Schools (PfS) is responsible for delivering the government’s secondary school renewal programme, Building Schools for the Future. (see page 11)

Introduction

z Commission for Architecture and the Built Environment (CABE): The DCSF has contracted CABE to be responsible for the overall setting of building quality, especially in the UK Building Schools for the Future (BSF) Scheme. CABE plays a vital role in the design and approval of new schools. More information is presented on page 14.

7

The Regulations and Guidance Documents

BB87BB 93

BB 101 BB 95

Commission forArchitecture and

the Built Environment(CABE)

Government(DCSF)

Partnership for Schools

(PFS)

BuildingRegulations

Part E: Acoustics

Building RegulationsPart L: Fuel and Power

Building RegulationsPart F: Ventilation

Education (School)Premises

Regulations (1999)

BREEAM Schools EPBD

BB 87Environmental

Design

BB 90Lighting Design

forSchools

BB 101Ventilation for Air

Quality and Cooling

BB 93Acoustics

BB 95Schools forthe Future

Carbon Trust(Schools Pack)

Eco Schools(Green Flag Award)

Management

Legislation

Certification

Formal Guides(Building Bulletins)

Other Energy Management

Initiatives

The Regulations

8 Case Study

Queensmead Primary School Braunstone, LeicesterConsultants: Silcock Dawson & PartnersA total of 18N° Windcatcher systems serving the Classrooms and 3N° GRP 1000 square systems serving the Main Hall. The systems not only look in keeping with the building exterior but they also maximise the use of cross ventilation from perimeter windows to give the best of both worlds for natural ventilation.

Individual Control

Each individual classroom can be provided with its own natural ventilation system and each system is programmed to react to internal temperature and CO2 levels. The Teacher has an individual override button to each classroom, so that the volume control dampers can be opened or closed and the system resets to automatic after 20 minutes.

9Case Study

Seaside School LancingArchitects: R H PartnershipTwenty Monodraught SunPipes and eight Sola-boost natural ventilation units with an 8-zone iNVent natural ventilation control system that monitors and controls the Sola-boost (as set out on page 28) units have been installed. The Sola-boost systems were chosen as part of a thermal model for the building, to work in tandem with the underfloor heating. If sensors detect that temperatures and/or CO2 levels in the classrooms have exceeded maximum pre-determined settings, the Sola-boost units automatically respond by bringing in fresh, natural air from the outside.

High Security Openings

One of the most important aspects of providing natural ventilation to schools is to maintain a high level of security. Windcatcher natural ventilation systems operate 24 hours a day without compromising the security of the building in any way. SunPipes, the mirror finish light pipes, as set out on Pages 34 and 35, pipe in natural light also optimising security.

10

Legislative Requirements

It is a fundamental requirement that Buildings comply with the relevant Regulations. In the case of schools, environmental and energy requirements are covered by the Education (Schools Premises) Regulations and the Building Regulations. Relevant details from these Acts are summarised below.

The Education

(Schools Premises) Act 1999

z Acoustics (Section 18) Each room or other space in a school building shall have the acoustic conditions and the insulation to noise appropriate to its normal use. Specific noise criteria deemed to satisfy this requirement is set out in Building Bulletins 93 and 101 (see pages 18 and 19).

z Lighting (Section 19)Prescribed lighting levels for schools are given as 300 lux on the working plane and 500 lux for visibility demanding activities. The glare index should be no greater than 19. Specific lighting requirements are given in Building Bulletin 90 (see page 18).

z Heating (Section 20) This section prescribes the minimum permitted room temperatures only. The given conditions must be met at a height of 0.5m above floor level and for outdoor air temperatures down to -1°C. Requirements are:

o Low activity rooms (sick rooms and isolation rooms but not bedrooms) 21°C.

o Normal activity rooms (teaching, private study and examinations) 18°C.

o Higher activity rooms and sleeping accommodation 15°C.

Criteria for overheating are covered by Part L2A of the Building regulations and by Building Bulletin 101 (see page 19).

z Ventilation (Section 21)Comprehensive requirements for fresh air ventilation are given. These require that:

1) All occupied areas in a school building shall have controllable ventilation at a minimum rate of 3 litres of fresh air per second for each of the maximum number of persons the area will accommodate.

2) All teaching accommodation, medical examination or treatment rooms, sick rooms, isolation rooms, sleeping and living accommodation shall also be capable of being ventilated at a minimum rate of 8 litres of fresh air per second for each of the usual number of people in those areas when such areas are occupied.

3) All washrooms shall be capable of being ventilated at a rate of at least 6 air changes an hour.

Items 1 and 2 above have formed the basis of much controversy but should be interpreted as requirements for unoccupied and occupied periods respectively.

Further information and interpretation is given in Building Bulletin 101 (see page 19).

The Building Regulations

z Ventilation (Part F Means of Ventilation)Ventilation must be provided and be capable, under normal circumstances, of limiting the accumulation of pollutants and moisture, which could lead to mold growth in a building and would otherwise become a hazard to health of people in the building. Prescribed details are left to the Education (Schools Premises) Act and to Building Bulletins 101 (see page 19).

z Acoustics (Part E Resistance to the Passage of sound) This states that requirements for sound insulation, reverberation time and ambient noise will be met by complying with the specifications given in Building Bulletin 93 (see page 18).

z Conservation of Fuel and Power (Part L2A)Energy efficiency measures and reduced carbon dioxide emissions are now essential. Part L2A covers the means of meeting emission and energy targets. This includes energy efficient lighting and the effective use of daylighting. It also addresses the avoidance of overheating which, for schools, is deemed to be satisfied by following the specifications given in Building Bulletin 101 (see page 19).

Introduction

Legislative Requirements

11

‘Building Schools for the Future’ Programme and ‘The Primary Capital’ Programme

Building Schools for the FutureThe Building Schools for the Future project is a 15 year programme to rebuild or renew every Secondary school in the country. It is at the heart of the government’s secondary school rebuilding plans to achieve a step change in the quality of education provision. Starting with the schools of greatest need, the target includes sufficient funding to renew at least one school in every local authority area by 2011 and at least three schools per area by 2016.

This programme also includes the development of new Academies, ensuring good provision for special needs and extended schools. Management of the programme is the responsibility of Partnership for Schools (PfS)

By the end of 2008 over half of the local authorities in England had become engaged in the programme, covering around 1,000 secondary schools.

The BSF programme presents a major long-term project with industry for the development of new schools. In particular the PfS has designed a simplified procurement system. This includes a comprehensive set of standardised procurement and contractual documentation. It is through this that all new secondary school development is taking place.

Further details: http://www.partnershipsforschools.org.uk/

The Primary Capital Programme -

Primary SchoolsThis programme mirrors that of the Secondary school programme and is committed to renewing at least half of all Primary schools by 2022. The key priorities include:

o Five per cent of the worst condition schools to be rebuilt or taken out of commission;

o At least 50 per cent of Primary schools overall to be rebuilt, refurbished or remodelled to bring them up to 21st-century standards;

o Targeting deprivation to locally determined criteria to be priority;

This activity involves much interaction with the Architectural and building sector. There are strong requirements for good quality design and fulfilling indoor environmental needs by means of natural ventilation and daylighting.

12 Case Study

Addey & Stanhope SchoolDeptford, LondonArchitect: Barron and Smith ArchitectsConsultant: Environmental Engineering PartnershipThirteen ‘top down’ Monodraught Windcatcher natural ventilation systems were installed in a major extension to the school, which is next to the busy A2 trunk road in Deptford. The Architect, Guy Shackle said, “I was impressed with the simplicity of the Windcatcher technology. The roof mounted units are located well above the heavy pollutants on the A2 allowing fresh air to be drawn into the heart of the building. Acoustic lining in the ducts of the Windcatchers has reduced noise ingress to 38 dBa, which is well within the noise design limits set by the Acoustic Consultants.” A variety of automatic controls related to temperature and air quality sensors were also provided by Monodraught.

City Schools

School building in City Centres brings its own problems of counteracting the effects of traffic pollution and traffic noise. Monodraught Windcatchers have proved themselves eminently suitable for such Projects, with acoustic lining being used to meet the stringent design requirements.

Construction Material

Windcatcher Size (mm)

Insulation Thickness (mm)

Damper Position

Sound Reduction (dB)

GRP 800 square unlined open 15

GRP 800 square 25 open 26



GRP 800 square unlined closed 30

GRP 800 square 25 closed 47



Acoustic MattersAcoustic issues are increasingly important with the stringent requirements of the Regulations and the dilemma faced by many Designers of the need to have ample ventilation without the attendant problems of noise ingress.

All Monodraught systems can be supplied with acoustic lining to all hard surfaces to provide degrees of sound attenuation. Extensive tests have been carried out at the Building Research Establishment (BRE) at Garston, Watford to test the effectiveness of Windcatchers in reducing noise ingress and the chart shown indicates the attenuation that can be achieved. The Monodraught system in its standard form has the effect of reducing noise transmission by 15dB as compared to an open window. However, by incorporating 25mm of acoustic lining to the air paths, a further 11dB can be achieved, as shown.

Note: Performance Standards in terms of maximum dB for ambient noise for naturally ventilated classrooms are set 5dB higher than the Standards that are required for mechanical ventilation.

13Case Study

Imperial College LondonArchitects: Gatehouse Architectural ConsultantsThe Library is on the top floor, with full height glazing and suffered for many years from chronic overheating in the summer months. However, the Windcatcher natural ventilation systems were the chosen strategy due to their energy saving features. Another major benefit and consideration for the College was the improved health and comfort aspects of natural ventilation systems, which have proved to provide a more calm and stress-free working and studying environment.

Phil Evans, Energy Manager says, “We are all aware how difficult it is to study and work in a stuffy and warm environment and this was one of the key factors in the College’s decision. After all, what could be more energy efficient than ‘free fresh air’.”

Architectural Design

One of the main advantages of Monodraught Windcatcher natural ventilation systems is the fact that they will blend in with virtually any building design. GRP used in their manufacture means there are no external visible fixings, virtually any colour or shape can be used, and GRP has been shown to be maintenance free throughout the intended life of the building.

14

The Commission for Architecture and the Built Environment (CABE)The Commission for Architecture and the Built Environment (CABE) is the Government established advisor on architecture, urban design and the public space. CABE has been appointed by the Department for Children, Schools and Families to provide extra support and guidance to local authorities to help them achieve well-designed schools. To achieve this, CABE has established the Schools Design Quality Programme (2007) and a School Design Panel for assessing school design. All schools that are part of the Building Schools for the Future Programme (BSF) are subject to the scrutiny the School Design Panel. It is therefore essential to ensure that the specifications set by CABE are fully satisfied. Assessment criteria are based on 10 key topics. Each topic is rated according to the classification of excellent, good, mediocre or poor. Higher rating is given to the use of natural light and ventilation wherever appropriate.

The CABE Design Audit - problems to be overcomeThe CABE recently published design audit (Creating Excellent Secondary Schools — A Guide to Clients) concluded that “Recently built school buildings performed very poorly in terms of sustainability. Many basic issues of energy performance had been overlooked, including the potential to minimise requirements for mechanical ventilation by use of passive ventilation approaches and to reduce electricity used for lighting by ensuring natural light within the buildings.

These are fundamental aspects of school design and need to be re-considered at brief stage”.

With respect to ventilation and the thermal environment the report went on to state that, “Ventilation and temperature were raised as important issues in all of the pilot schools. Often users felt spaces were too hot or too cold and they could not always regulate their own environment”. For lighting the report stated that “users wanted natural light”.

The CABE Design Audit reported poor sustainability performance as a result of lack of natural ventilation and daylighting

z Recently built school buildings performed very poorly in terms of sustainability.

z Many basic issues of energy performance had been overlooked, including the potential to minimise requirements for mechanical ventilation by use of passive ventilation approaches and to reduce electricity use for lighting by ensuring natural light within the buildings.

z These are fundamental aspects of school design and need to be more carefully considered at the brief stage.

In its “Ten Points for a Well Designed School Section” the report stresses the need for “good environmental conditions throughout including optimum levels of natural light and ventilation for different activities”.

The following 10 points are the criteria against which every school proposal is assessed:

z Identity and context: making a school the students and community can be proud of.

z Site plan: making best use of the site.

z School grounds: making assets of the outdoor spaces.

z Organisation: creating a clear diagram for the buildings.

z Buildings: making form, massing and appearance work together.

z Interiors: creating excellent spaces for learning and teaching.

z Resources: deploying convincing environmental strategies.

z Feeling safe: creating a secure and welcoming place.

z Long life, loose fit: creating a school that can adapt and evolve in the future.

z Successful synthesis: making a design that works in the round.

CABE

15

The BREEAM SchemeBREEAM is an environmental assessment method which is supported by the UK Government as a means to ensure the optimum environmental performance of buildings. This scheme covers a whole range of buildings including Primary and Secondary schools. The method addresses the areas of:

o Management

o Energy

o Health and Well Being

o Pollution

o Transport

o Land Use

o Ecology

o Materials

o Water Use

In each case credits are awarded and the building is given an overall rating of either Excellent, Very Good, Good or Pass. Full details are contained in the BREEAM Schools Assessor’s Manual. The assessment itself is undertaken by a qualified independent assessor.

In the case of schools, the DCSF requires that both new build and refurbishment school projects undergo a BREEAM environmental and energy assessment and achieve no less than a BREEAM ‘Very good” rating.

Areas relating to Natural Ventilation and Daylighting and thermal comfort are covered by BREEAM test procedures. Specific items cover:

z Credit for Natural Daylighting (Section HW1 of the Technical Manual): A maximum of two credits is given where all occupied spaces are adequately provided with natural daylighting and one credit is given where at least 80% of occupied areas are provided with daylighting.

z Credit for Natural Ventilation (Section HW8 of the Technical Manual): This requires controllable draught free ventilation to meet the requirements for good indoor air quality. For plan depths greater than 7m openable windows or vents must be located on opposite faces. In cases where the plan depth is greater than 15m adequate cross flow ventilation must be provided. Top down ventilation meets these requirements.

z Thermal Comfort: (Section HW14 of the Technical Manual): Credit is given for limiting overheating hours no greater than 40 hours above 28°C when applying CIBSE Guide J Test Weather Year.

Note: This is somewhat different to BB 101 requirements that refers to a requirement of 120 hours.

BREEAM Schools Assessment

Energy Performance CertificatesThe display of Energy Certificates (DEC’s) and Energy Performance Certificates (EPC’s) form part of the European Energy Performance in Buildings Directive. Buildings (including schools) of floor areas greater than 1000m2 must display a DEC by October 1st 2008. An EPC is additionally required when a building is constructed, sold or let. This scheme requires independent assessment by a qualified assessor.

The DCSF requires both new and refurbished

school projects undergo a BREEAM assessment

and achieve no less than a ‘very good’ rating

‘‘’’

BREEAM

16 Case Studies

Kidderminster CollegeKidderminsterArchitect: GVA Grimley1000mm diameter Windcatcher systems were used to ventilate a series of classrooms on the top floor of this new College. Traditionally it is the classrooms on the top floor that suffer the most from solar gain, so this is where natural ventilation is at its most effective.

Tranent North Primary School East LothianSpecifier: East Lothian Council, Community Housing & Property ManagementMonodraught Windcatchers have proved extremely popular in Scotland being specified and installed now on more than 60 schools in the Scottish region. This is all under the direction of Monodraught’s Agents in Scotland, JRF Services of Glenrothes in Fife.

17Case Study

Peckham AcademyLondonArchitect: Curl La Tourelle ArchitectsConsultant: Halcrow Group LtdThe £23m Academy in central London consists of 3-storey buildings, where it was necessary to provide natural ventilation not only to the top floor but also to the two floors below. Monodraught Windcatchers were used to provide a sustainable solution to achieve ventilation to deep plan classrooms on multiple floors. The top floor classrooms are served by 800mm units, positioned in the centre of each room, whereas ground and first floors are served by rectangular units measuring 1300mm x 450mm, connected up to internal blockwork ventilation shafts formed in the walls of the central corridors.

Deflector plate

Classroom Corridor

ExhaustAir

PrevailingWind

New City Academies

With the upsurge in City Academies, the provision of natural ventilation is proving to have a most important part to play in the design. There is no noise, no maintenance, and no replacement cost with natural ventilation systems but most importantly, they are energy free and provide a constant supply of fresh air and oxygen for the benefit of both students and the teaching staff.

18

The DCSF School Building Bulletins (BB)These documents are published by the Government Department for Children, Schools and Families (DCSF). They explain how the relevant Building Regulations can be satisfied. The relevant bulletins are:

z BB 87 Guidelines for Environmental Design in Schools: This provides a constructional standard for environmental conditions and the conservation of fuel and power. It has sections on ventilation and the avoidance of overheating. There are some differences with respect the overheating specification compared to that given in Part L of the Building Regulations in the BREEAM assessment scheme. BB 87 specifies a permissible 80 hours of temperature above 28°C compared to BB 101 (for Part L compliance) of 120 hours and a BREEAM value of 40 hours. Very importantly BB 87 states that “Wherever possible priority should be given to design for daylight as the main source of light in working areas.

While good designs take advantage of windows, windows can themselves be a contributory factor to summer overheating and excessive glare, especially when south facing. Often blinds are used to deflect glare but this reduces daylight, with the result that artificial lighting then has to be used (resulting in higher carbon emissions and more heat gain). SunPipes can overcome such problems by penetrating areas where window lighting is not possible or where too much glazing will cause overheating.

z BB 90 Lighting Design for Schools: This is the fundamental guide for lighting. Its introduction stresses that: “Natural lighting during daylight hours should always be the major source, supplemented when it fades by electric light which will take over during hours of darkness.” The reasons for this need for natural light stem both from the important link with the outside and the essential character of daylight and its changing value throughout the teaching day which electric light cannot replicate. While the document recognises that natural lighting cannot always be used Section 3.1 of the Guide goes on to state that “Unless there are over-riding educational reasons for not doing so in certain rooms, the school designer should assume that daylight will be the prime means of lighting when it is available”

z BB 93 Acoustic Design of Schools – a Design Guide: The acoustic specifications are important because noise can be generated by mechanical systems and transmitted through ventilation ducts.

o Performance Standards in terms of maximum dB for ambient noise for naturally ventilated Classrooms are set 5dB higher than the Standards that are required for mechanical ventilation.

z BB 95 Schools for the Future This addresses designs for new school or refurbishment projects including:

o The promotion of good design in public buildings, along the lines encouraged by the Commission for Architecture and the Built Environment CABE).

o The development of designs which will minimise the environmental impact of building through low energy use.

Strong emphasis is given to natural ventilation and daylighting: Section 2B.1 on lighting states that:

o Daylight should be the principle means of illumination where possible (this is especially important for visual disciplines such as art).

o A space can be considered well daylit if it has an average daylight factor of 4-5% and a uniformity ratio of 0.3-0.4. Daylighting should therefore be considered at the earliest planning stage.

Requirements for Natural Ventilation are covered in Section 2B.3 This stresses the need to:

o Aim for natural ventilation where possible.

o Avoid air conditioning which is not generally required in schools and should be avoided because of its high cost and energy consumption.

Building Bulletins

19

z BB 101 Ventilation of School Buildings - Regulations Standards and Design Guidance: This provides the regulatory framework in support of the Building Regulations (Part F and L) and the Schools Premises Act for securing the adequate provision of ventilation in schools and preventing overheating. Specifications cover:

o Air Quality Criteria: Ventilation for air quality criteria are the same as those given in the Education (School Premises) Regulations.

o Avoidance of Overheating (Compliance with Part L2A): The performance standards to avoid summertime overheating for teaching and learning areas are given in BB 101 as:

a) There should be no more than 120 hours when the air temperature in the classroom rises above 28°C;

b) The average internal to external temperature difference should not exceed 5°C i.e. the internal air temperature should be no more than 5°C above the external air temperature on average (between May to September);

c) The internal air temperature when the space is occupied should not exceed 32°C.

Designers are required to meet any two of the above three performance standards.

Builders have created air-tight classrooms which are intended to reduce heat loss but they also stop carbon dioxide escaping.Higher CO

2 levels in newly-built schools are leaving children drowsy and less able to concentrate, researchers from University College London and Reading University found.The studies will come as a blow to Children’s Secretary Ed Balls,

who wants every new school to be “zero-carbon” from 2016. UCL researcher Dr Dejan Mumovic said ministers had “rushed” their sustainable schools programme. He monitored 10 schools built 50 year ago and nine erected under the Government’s £45 billion Building Schools for the Future programme. “The ventilation rates were equally appalling,” he told the Times Educational Supplement. CO

2 levels are exceeding targets, and that can affect the learning performances of kids.”Kim Knappett, a science teacher from Forest Hill School in

Lewisham, said her new classrooms were either far too hot or freezing. Stiflingly hot classrooms lead to an increase in disruptive behaviour as pupils become “irritable”, she said.“It’s just too hot and everybody falls asleep or gets ratty,” Ms

Knappett told the Standard. “They can’t work properly.”A separate study by Reading University tested the reaction times and memory of pupils in rooms with high levels of CO

2. Professor Derek Clements-Croome, who led the research, said: “When the CO

2 was very high, the reaction times would slow and memory would be affected. The kids would also get drowsier.“You may not even detect that it’s getting stuffier in the room but

once higher CO2 levels are breathed in it gets into the blood and

goes to the brain.”

EVENING STANDARD FRIDAY DECEMBER 19th 2008EDUCATIONChildren falling asleep in classroomsBy Tim Ross

Other Initiatives z The Carbon Trust: The Carbon Trust is

responsible for advising the public and private sector on methods to achieve the Government targets on greenhouse gas emissions. It has published a schools information pack and provides energy saving guidance for schools.

z Eco Schools: Eco Schools, in partnership with the Award Scheme Development and Accreditation Network (ASDAN), has developed a national programme for promoting energy and environmental efficiency in schools by involving teachers and pupils.

z Energy Performance Certificates (EPBD): Schools with individual building floor areas of greater than 1000 m2 require the commissioning and display of an Energy Performance Certificate.

Note: The BREEAM requirement for an “excellent” rating are somewhat more stringent than BB 101 (please see page 15).

and what the papers say ...!

20 Case Study

St Joseph’s College IpswichArchitect: Wincer KievenvaarConsultant: Johns, Slater & HawardA state-of-the-art Infants and Junior School characterised by the use of bold organic forms, natural light and bright colours designed to inspire its young pupils, provides a clear statement of environmental intent by naturally ventilating the 125 square metre hall, a circular library and a series of interlinked shared spaces. Greg Allen, Facilities Manager at St Joseph’s College says, “The systems have regulated the internal temperatures without any outside assistance.”

Architects can have fun!Using the fairly dominant appearance of Windcatcher systems, an Architect can have a field day on some very striking designs for their school building! Colours as well as shapes can be used to great effect.

21Bespoke Systems

Some more interesting shapes and colours!

22

The Importance of Natural Ventilation for Air Quality

Monodraught Windcatchers satisfy all these needs by incorporating the top down natural ventilation technique.

Any prevailing wind is encapsulated by the louvres on the windward side of the Monodraught system and this air is

turned through 90° to provide a continuous airflow down to the room below. Motorised volume control dampers, together with a sophisticated control system, can accurately control this airflow to provide the desired ventilation rate.

Since the airflow is drawn from above roof level, the air is generally much cleaner than it would be drawn through

windows or low level intakes. By drawing air in from high level, this avoids dust, dirt, and often traffic pollution that generally circulates at pedestrian level.

Since the downflow of incoming air is generally much cooler and being wind driven, it has been proven through

many years of testing that this airflow descends to floor level, similar to a displacement ventilation system. But without any energy costs!

Constant movement of air to floor level tends to slightly pressurise the room which the Windcatcher serves, and

this incoming air helps to displace the warm air that rises through the natural passive stack effect of the leeward side of the Monodraught system.

Warm air will naturally rise to ceiling level in any room and since the air ducts are open to atmosphere

“passive stack ventilation” is created.

A ir movement over the top of the Monodraught system also helps to create a venturi effect on the leeward side

of the Monodraught Windcatcher system also assisting in extracting stale air from the room.

The interaction of free night-time cooling cannot be overstated. During the summer months, the volume

control dampers on the Monodraught systems are programmed to open fully at midnight to allow the cool night air to descend down to floor level. This tends to slightly pressurise the room forcing the stale warmer air up through the leeward side of the Monodraught system situated at roof level. Warm air will rise naturally, so even if there is no wind blowing at night-time, the warm air will always rise up to roof level, rising up and being exhausted to atmosphere, since this action cannot create a vacuum, cool night air will descend to replace the warm air that has been exhausted. It follows when there is any prevailing wind from any direction, this will simply increase the throughput of this fresh ventilation air, purging the building of stale odours and the residue of any heat build up, which has been created the day before.

Weatherprooflouvres

Motorised volumecontrol dampers

Ceiling diffuser

Freshair in

Staleair out

Internaldivider

Anti birdmesh

PLAN VIEW

air out

air in

What the regulations say:

Natural ventilation is the process by which fresh air is provided without the use of mechanical systems. Demonstrating the maximum use of natural ventilation in preference to mechanical ventilation systems forms a significant part of the CABE and BREEAM assessment criteria. The DCSF Building Bulletin 87 on Guidelines for Environmental Design in Schools states that natural ventilation should be taken as the default design solution for the ventilation of school classrooms. BB 95 on Schools for the Future stresses the need to use natural ventilation whenever possible. The Carbon Trust stresses that air conditioning should be avoided because of its high cost and energy consumption.

Air Quality

The Windcatcher design

23

Natural Ventilation for Healthy Buildings

Metabolic Carbon DioxideCarbon dioxide (CO2) is emitted as a metabolic pollutant. Like all pollutants, the concentration reached in a space is dependent on the rate of ventilation and the emission rate of CO2 itself. For a fixed rate of activity, the rate of emission is fairly uniform, the concentration of CO2 can give an estimate of the actual ventilation rate. It can also alert occupants to the possibility that a space is under-ventilated and can be used, in a control system, to actuate ventilation dampers. For this reason it is recommended that schools are fitted with CO2 detectors. In some countries this is becoming a legal requirement.

At the concentrations experienced in normal day to day life, carbon dioxide is not toxic. No matter what level of CO2 is measured in a school, workplace or home, it will be very unlikely to reach a toxic concentration. The limit value quoted for schools is many times lower than maximum safety limit. The reason why CO2 monitoring is so important is not because of the pollution effects of carbon dioxide itself but because it provides an indication of the fresh air ventilation rate. It also acts as a surrogate for other pollutants that cannot be measured so easily but might cause a risk to health in poorly ventilated spaces.

This is further supported by extensive research carried out by Reading University and UCL London as reported by the Evening Standard and has been reproduced on page 19.

Recommended Maximum CO2 Concentrations (As set out in BB 101)

When measured at seated head height, during the continuous period between the start and finish of teaching on any day, the average concentration of carbon dioxide should not exceed 1500 parts per million (ppm).

In addition to the requirement to meet the CO2 performance standard stated above, it is recommended that the design should also meet the following advisory performance standards that reflect the needs of the School Premises Regulations and the recommendations of the Health and Safety Executive.

i) The maximum concentration of carbon dioxide should not exceed 5000 ppm during the teaching day.

ii) At any occupied time, including teaching, the occupants or the design of the ventilation system should be capable of lowering the concentration of carbon dioxide to 1000 ppm.

Additional ventilation rates are required for areas used for special activities, such as science laboratories and food technology rooms etc.

The accurate monitoring and control of CO2 levels is now considered as one of the most important factors in School Classroom design.

20°C

25°C

WindcatcherSummer DaytimeOperation

WindcatcherNight timeOperation(and mid-season)

All necessary steps should be taken to

ensure that CO2 levels do not exceed

1500 ppm during occupied times

‘‘’’

Reducing CO2

24 Case Study

Penryn College CornwallArchitect: Poynton Bradbury Wynter Cole Cornwall’s BSF Pathfinder project opened a year ahead of any other projects in this funding group – the £20m scheme provides some 8500 square metres of new accommodation for 1150 pupils aged 11-18 and achieved a BREEAM ‘Excellent’ rating. The demand for outstanding environmental performance was achieved with an Architectural design approach with daylighting and natural ventilation and cooling prioritised. A total of 42N° Monodraught Windcatchers, SunPipes, and Monovents, were used throughout the Project, the largest units being some 3.3m x 2m on plan. Some of the smaller units were used on a green roof design.

From early beginnings....

When Windcatchers were first launched 15 years ago, they were often used on existing schools to overcome severe overheating problems. Such was their success on existing schools, now 70% of Monodraught Windcatchers are installed on new build schools and academies, having proved their success and sustainability over a number of years.

25Case Study

Cranbrook Primary School IlfordThe London Borough of RedbridgeA total of 28N° GRP circular Windcatcher systems serving Classrooms and Halls were provided to this school. Seventeen of the systems has specially designed twin duct arrangements so that a room on each floor can be served by a single system. This allowed for a total of 34 rooms to be served in addition to the two Main Halls as well as four other classroom areas.

0

200

400

600

800

1000

1200

1400

1600

1988 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Total Number of Windcatcher installations 1995 to 2008

School Windcatcher

Total Windcatcher

YEAR ALL W/C School W/C Others Schools 38921988 6 0 6 Offices 6471995 2 2 0 Police 1321996 8 0 8 Hospitals 2811997 83 35 48 Sports Centre 1621998 58 41 17 Comm. Centres 1951999 219 70 149 Sure Starts 212000 282 154 128 Libraries 312001 275 195 80 Theatres/Restaurants 372002 343 248 95 Toilets 52003 413 285 128 Military 312004 625 454 171 Domestic 162005 801 555 246 Stores 332006 1058 760 298 Vets/Zoo 222007 1277 952 325 Churches 112008 1441 1056 385 Temples 6

up to 31.12.2008 Airport 185540

1441.00 1056.00

0.60%0.29%0.56%

100.00%

0.20%0.32%

0.20%0.40%

3.52%

Analysis over 6 years2002 ~ 2008

0.09%0.67%0.56%0.38%

Comparison in Windcatcher Installations

2.92%5.07%2.38%11.68%70.25%

0

200

400

600

800

1000

1200

1400

1600

1988 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008


School Windcatcher

Total Windcatcher


up to 31.12.2008 Airport 185540

1441.00 1056.00

0.60%0.29%0.56%

100.00%

0.20%0.32%

0.20%0.40%

3.52%


0.09%0.67%0.56%0.38%


2.92%5.07%2.38%11.68%70.25%

0

200

400

600

800

1000

1200

1400

1600

1988 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008


School Windcatcher

Total Windcatcher


up to 31.12.2008 Airport 185540

1441.00 1056.00

0.60%0.29%0.56%

100.00%

0.20%0.32%

0.20%0.40%

3.52%


0.09%0.67%0.56%0.38%


2.92%5.07%2.38%11.68%70.25%

....strong development

70% of all Windcatcher systems supplied over the last six years have been installed on Schools, Sports Centres, Sure Starts, Libraries, and Community Centres, also feature strongly in the list of Projects demanding natural ventilation, as a way of not only reducing energy costs but also to improve the health and indoor environment of their Projects.

26

Winter Heat Loss - addressing the myth....

Winter Heat LossConcern is often expressed that, during the winter, excessive heat and energy can be lost through the exhausting of ventilation air. It is for this reason that there can be a perceived conflict between providing the ventilation needed to ensure optimum health and productivity, and a desire to reduce building heatloss. Sometimes heat recovery units are specified but these can result in extra use of electrical energy thereby defeating the object of reducing the carbon footprint and reducing energy consumption, furthermore these require a continuing maintenance commitment to ensure that filters are regularly replaced and that ducts are kept clean since otherwise there maybe a deterioration in health.

In reality, for a well insulated school, such heatloss may not have as much of an additional space heating burden as some calculations may suggest. On the basis of an average outdoor winter daytime temperature of between 6 - 12°C and an indoor temperature of 20°C, the BB 101 requirement for an average daily carbon dioxide concentration not to exceed 1500 ppm can be met with a heat input of under 100 W per occupant (see Figure). In practical terms this can be expected to be satisfied by the metabolic heat emission of occupants combined with surrounding incidental gains from lighting, IT equipment and other sources. For much of the time, the more demanding specification of 1000 ppm CO2 concentration can also be accomplished without significant extra space heating demand. However, to minimise ventilation heatloss, control is essential. This is needed to ensure that the ventilation rate is continuously matched to meet occupant

loading and to prevent excessive air change rates during unoccupied periods. Such control can most efficiently be achieved by ensuring that the building structure is airtight and by monitoring and maintaining carbon dioxide concentration in the 1000 ppm to 1500 ppm range. At night time, when outdoor temperatures reach their lowest values, demand for ventilation is greatly reduced and hence night time ventilation heat loss can largely be eliminated. Natural ventilation may therefore be expected to provide reliable winter ventilation, at the full rate demanded by occupants, without resulting in excessive energy loss.

Outdoor Air QualityNatural ventilation cannot, in itself, compensate for poor outdoor air quality. Fortunately much research has been undertaken in recent years to reduce problems associated with poor outdoor air quality. Local Authorities are now required to monitor urban air quality and designate zones of poor air quality as Air Quality Management Areas. Action plans must then be developed and enforced to improve the air quality in these zones. There are also restrictions on emissions and on the location of air exhausts and fresh air intakes. This is resulting in continuing improvement to outdoor air quality.

Nevertheless some air pollution problems can occur and these may often be dependent on weather conditions. As a general rule, air intakes at low level and facing busy roads are more likely to cause air

quality problems inside a space than those placed at high level or indeed at roof level and away from traffic sources. There can sometimes be problems of dust ingress or traffic pollution through low level air intakes and complications with conventional windows and intakes placed in courtyards because stale air can become trapped in such zones. Monodraught Windcatchers can effectively overcome this range of problems by taking in fresh air at roof level, since the air supply at roof level is relatively clean and uncontaminated as compared to low level air intakes sited at ground or pedestrian level.

Vent

ilatio

n H

eat L

oss

(W)

Ventilation Rate (L/s)

Ventilation Heat Loss for typical Winter Daytime Temperatures

200

150

100

50

5 L/sfor 1500 ppm

CO2 concentration(average required

by BB101)

8 L/s(for 1000 ppm CO2

concentration)

Typical temperature, ventilation rate and winter ventilation

heat loss (per occupant)

By good controlBB101 CO2

requirements canbe satisfied at

less than 100 W ventilation heat loss

6ºC Outdoor

Temperature

12ºC Outdoor

Temperature

143 W

82 W

89 W

51 W

1 2 3 4 6 7 9 10 11 12

Winter Heat Loss

27

Natural Ventilation for Cooling

Avoid OverheatingOverheating is an increasing problem for schools, particularly in view of global warming. Often it occurs not only as a result of high outdoor air temperature but also because of high indoor heat gains. Major sources of heat gain are IT equipment, artificial lighting, occupants themselves and solar gain caused by the direct effect of the sun. Control of indoor gains is therefore essential.

Avoidance of overheating is covered by Part L2A of the Building Regulations. This requires compliance with the performance standards to avoid summertime overheating for teaching and learning as set out in BB 101. These state that two of the following must be met:

a) There should be no more than 120 hours when the air temperature in the classroom rises above 28°C;

b) The average internal to external temperature difference should not exceed 5°C i.e. the internal air temperature should be no more than 5°C above the external air temperature on average (between May to September);

c) The internal air temperature when the space is occupied should not exceed 32°C.

It should be noted that to obtain a credit under the BREEAM assessment scheme the limit on number of hours over 28°C has been set at 40 hours.

For UK climate conditions natural ventilation can provide the main mechanism for maintaining the thermal comfort

conditions considered necessary during the summer months by flushing hot indoor air from the building with cooler outdoor air, this is particularly beneficial with of top down ventilation provided by Monodraught Windcatchers.

Night-Time CoolingProbably one of the most successful aspects of top down natural ventilation systems is the ability to provide “secure” night-time cooling, with virtually no energy costs and providing 100% security to the building.

During summer months, there is often a build-up throughout the day of solar gain as well as occupier heat gains. Under normal circumstances in many schools, windows and doors are shut up tight after the school children have left for the day only reopening the following morning!

Night-time cooling provided by Monodraught Windcatchers means that at midnight, dampers are automatically programmed to open to allow the night-time cool air to descend to floor level, not only purging the building of stale air but also cooling down the interior of the building, as well as the building mass and structure of the building.

Monodraught Windcatchers controls are programmed to close the dampers automatically at 15°C to prevent the building from overcooling but otherwise, this ventilation arrangement provides approximately 8 hours of free cleansing and cooling of the building interior, which is essential for the successful application of natural ventilation.

Programme SettingsMonodraught’s iNVent control system provides settings for winter and summer as well as spring and autumn, to ensure that night-time cooling only occurs during summer months when natural ventilation is essential. These settings are as follows:-

Temperature Spring Summer Autumn WinterUp to 16°C

Dampers remain closed




At 17°C Dampers open 20%



At 20°C Dampers open 20% Dampers open 80% Dampers open 20%


Dampers full open

Dampers open 40%



At 24°C

Dampers fully open Dampers fully open

Dampers open 15%

At 25°CDampers open 20%

At 26°C

Night-time cooling

BREEAM state that overheating in classrooms can create problems of ‘‘ ’’

headaches, lethargy, irritated eyes

Note: CO2 sensors will override internal temperature readings when CO2 exceeds 1500 ppm

BREEAM Schools Document HW14and increased accident rates

Cooling

iNVent Control Panel

28 Case Study

Hazeley SchoolMilton KeynesConsultant: Architecture MKMilton Keynes were one of the first Authorities to implement the Sola-boost Windcatchers throughout on new school development in conjunction with SunPipes to serve every classroom. Over the last 15 years, Windcatchers have proved to be so successful in eliminating the need for air conditioning in classrooms, the Sola-boost system seemed a natural step for the Architects to further improve and enhance the natural ventilation capabilities. Each classroom is served by a separate Sola-boost Windcatcher system to both the first floor and ground floor classrooms and SunPipes are similarly used to bring daylight down into the rear of the ground floor classrooms.

Motorised volumecontrol dampers

Freshair in

Staleair out

FAN

Solar Power

airout

air in

PLAN

SECTION

Sunny Summer Day

The Sola-boost system

The Sola-boost innovation

An extension of the successful Monodraught Windcatcher system, is the Sola-boost. This is driven by a photovoltaic panel and operates during summer months when the sun’s energy produces 5 Volts or more. The solar power of the Sola-boost powers an integral fan that produces an extra 260 l/s of ventilation air.

29Case Study

Sir William Ramsay SchoolHazlemere, BucksArchitect: Jacobs UK LtdTwelve Monodraught Windcatchers were installed at the Performing Arts Block of the Hazlemere based Sir William Ramsay School, to provide natural ventilation for its 600-seat Main Hall and adjacent Dance and Performance areas. Their business manager Richard Mapp says: “Monodraught’s Windcatchers were the ideal solution and the entire facility now stays cool and refreshed, even when full of students letting off steam.” He adds “that once installed, Windcatchers maximise the use of wind pressure and the natural stack effect of thermal buoyancy, which means schools reap all the benefits of sustainable energy and incur no running costs.”

Sports Halls

Monodraught Windcatchers are ideal for Sports Halls in providing energy free ventilation – around the clock! An adequate supply of fresh air is essential to Sports Facilities but mechanical ventilation can often prove noisy, as well as being maintenance hungry.

30

Natural DaylightingDCSF Building Bulletin 90: Lighting

Design for Schools stresses that: “Natural lighting during daylight hours should always be the major source, supplemented when it fades by electric light which will take over during hours of darkness.” The reasons for this need for natural light stem from the essential character of daylight and its changing value throughout the teaching day which electric light cannot replicate. It goes on to state “Daylight should be the prime means of lighting when it is available”. Monodraught SunPipes do meet this challenge in being able to provide typically 2%/4% Daylight Factor to light up the rear of classrooms and other internal teaching areas, as well as corridors, offices, cloakrooms, and virtually all areas of school buildings that cannot easily be served by windows.

Natural Daylighting

31

Natural Daylighting - The Solution

Monodraught SunPipes have been used extensively throughout schools with considerable advantages. SunPipes consist of a mirror-finish aluminium tube with a Diamond shaped dome at roof level to keep out dust, dirt and rain. There is virtually no limit to the length of SunPipe or the number of elbows that can be used to twist and turn to bring the SunPipe to exactly where it is required. SunPipes are produced in a range of 10 different sizes from 230mm diameter to 1500mm diameter.

Windows can be used for bringing in daylight to the first 5m of a classroom and rooflights are often used to bring in natural daylight to the rear of classrooms. However, the disadvantages of rooflights can be:-

o Unacceptable glare in summer months

o Heat loss during the winter

o Excessive solar gain in the summer

The distinct advantage of SunPipes is that the closed tube of still air acts like a giant double glazed unit, virtually eliminating heat loss in the winter and solar gain in the summer.

SunPipes maximise the concept of renewable energy by reflecting and intensifying sunlight and even daylight down through the mirror-finish aluminium tube to the room below. A UV stabilised diamond shaped dome seals the SunPipe at roof level and a clear, stipple finish, polycarbonate diffuser at ceiling level evenly spreads light into the room or space below. The SunPipe system is highly effective in both sunny and overcast conditions and even when it is raining.

SunPipes have the distinct advantage of providing soft, soothing natural light to virtually any part of the schoolroom or classroom. SunPipes are known to have a calming and soothing effect on children and by eliminating the need for constant electric lighting, they are not only energy saving but contributing to both the children and the Teacher’s health and well-being. They are vandal-resistant , require no maintenance, and are compatible with any building design, although special finishes and ceiling trims are available.

The Solution

32 Case Study

Trinity & St Nicholas Primary Schools RadstockConsultant: King Shaw AssociatesTrinity School in North Radstock and St Nicholas School in South Radstock are jointly known as the Renaissance Project. They are part of a rationalization programme undertaken by Bath and North East Somerset Council and are bristling with new innovative and sustainable ideas. Tim Goodwin, the Senior Partner of Architects, King Shaw Associates explained, “We take the view that a holistic approach to engineering design results in more complete and fully integrated solutions, which apply to an entire building. We decided to replace many of the conventional skylights originally proposed by using Monodraught SunPipes because of the many advantages that these SunPipe systems provide. We considered that Windcatchers were an excellent way to ensure good natural air distribution and to meet the brief of providing a cost effective natural ventilation system within the building envelope budget.”

The perfect combination

SunPipes eliminate the heat gain normally associated with skylights and rooflights and provide energy free lighting from dawn until dusk, eliminating the need for electric lighting during daytime use. Having reduced the heat gain problem, natural ventilation Windcatchers offer the perfect complement by introducing fresh air into the space. Natural light and natural ventilation is just what every schoolchild needs.

33Case Study

Jack Tizzard SchoolLondonArchitect: Clarke Kidwell ArchitectsJack Tizzard School in Ealing, West London was a Special Needs School and it was considered that the soothing and calming effect afforded by SunPipes creates the ideal environment for children with special needs. A high level of security is desirable. The absence of distraction created by view out from windows and the absence of stress caused by fluorescent lighting all contribute to a far healthier and more friendly environment.

Special Needs School

The combined benefits of a highly secure, non-electrical light source that provides an abundance of natural light combined with the soothing and calming effect of natural light produced through SunPipe systems makes them particularly suitable for Special Needs Schools. The SunPipes not only reflect the mood of the outside weather conditions but also contribute considerably to the health giving properties of natural light availability.

Code 4 leadflashing

3 piece ceiling diffuser

30° two pieceadjustableelbow

Mirror finish aluminium tube with 98% reflectance

The SunPipe system

34

SunPipe and its benefits in Schools

approximately 20% in a well designed classroom with diffused light. The observations from the study revealed that the natural daylight from skylights had larger impacts on the positive results of student performance over all the other attributes of windows (view-out, etc.). The possible causes of good performance from the students due to daylighting were identified and summarised as improved visibility (due to higher illumination levels and light quality), better distribution and colour rendering.

A study on the Johnston County School by Nicklas and Bailey, 1997 investigated the academic benefits of daylighting and found that students in daylit schools had higher math and reading scores when compared to the scores of the children who studied in an artificially lit environment. At the daylit Durant Road Middle School in North Carolina, the teachers who worked there for more than a year, stated they feel better both mentally and physically because of the daylit environment (Bailey,1998 cited in Edwards & Torcellini, 2002). The study by Kuller,R and Lindsten.C, 1992 asserted that there was a strong association between the amount of daylight and a student’s behaviour especially when ranked for sociability and concentration. Even the Daystar article, ‘Benefits of Natural

gains and heat losses (in summer and winter) through the glazing (Lighting guide LG10, 1999). In such conditions the solar heat gain and light penetration may need to be controlled to avoid discomfort, by the use of appropriate shading devices (internal or external) such as window blinds.

Daylight and HealthPhysiological benefits due to daylight on school children can include less dental decay, improved eyesight, improved growth and immune system. Indeed Edwards and Torcellini (2002); McBeath and Zuker(Liberman 1991) and Hathaway, et al 1992; showed there is a strong correlation between the amount of sunlight a child is exposed to and the level of dental decay, making daylight a very important element for cavity prevention in children.

Daylight and PerformanceNumerous studies have proved the positive influence of daylight on students and teachers. The findings of the Heschong Mahone group, 1999 clearly show the impact of daylight on school children. The students with the most daylighting in their classroom performed 20% faster on math tests and 26% faster on reading tests in one year than those with the least. Similarly students’ progression was improved by

Umayal studied at Nottingham University on the Effects of Daylight on Human Perception. Her research proved invaluable to Monodraught in highlighting and identifying how the piping in of sunlight and natural daylight can be beneficial to children.

Daylight is a vital natural resource for schools, being preferred to electric lighting

because of its varied intensity, pattern and colour. It is a mixture of diffuse light from the sky and direct light from the sun, and it is said that when entering through a space, natural light defines and models an interior space, creating a pleasant visual environment and a feeling of well being, which by itself stimulates performance (Lighting Guide LG10, 1999).

Early designs of schools had classrooms with large windows, but as school designs have advanced the problems of space constraints, the need for flexible spaces and portable concepts conflicted with the preferred daylight design of many schools.

Daylight and thermal comfort sometimes conflict with each other i.e. the greater the window area, the greater the amount of daylight penetrating inside the space, but this leads to greater heat

By Umayal Ramanathan, M.Arch Environmental designResearcher for Monodraught Ltd

SunPipe Benefits

‘‘

35

. . . the health benefits of SunPipes

Daylighting’ (1998, ibid) states that there is increased achievement rates, reduced fatigue factors, improved student health, improved attendance and enhancement of general development.

From the above research and studies it is evident that an abundance of natural daylight influences humans, physically and psychologically to a great extent .Since buildings are designed for human habitation; lighting designs should consider psycho-physiological well being to provide a healthy environment. When the individual well being is enhanced the mood, performance, attitude, and the overall progress in academics will also be improved.

Top LightingA top lit classroom is said to provide three times more light, than the same area of vertical glazing that restricts natural light within an area of 6m from the wall containing the window. Higher illumination can improve visibility of task, and speed and

accuracy of students performing the tasks.

Daylight has better light quality than electric lighting in terms of distribution, colour rendering and modelling and is more appropriate for performing visual tasks. The variability of daylight brings in greater interest to the occupants which cannot be achieved by any type of electric lighting.

It can also be said that children’s improvement in performance can be attributed to lack of distraction from the view out of conventional windows.

SunPipesA growing body of evidence suggests that daylighting plays an important non-visual role in human health and well-being through the circadian system. Currently in the United Kingdom, there is only little scientific evidence available about the effects of daylighting in schools on student achievement or health through the circadian system, however even with little proof, it shows positive effects and the considerations are worthy of being followed. The magnitude of advantages and benefits that the daylight provides to the students and teachers with the use of SunPipes is enormous and magnificent.

SunPipe Benefits

’’ Umayal Ramanathan - 2009

36 Case Study

The British School at Abu Dhabi Abu DhabiOriginally the Architect wanted a series of free form rooflights but such is the intense heat of the sun in the Middle East, the Architect opted for a series of SunPipes arranged not in a uniform pattern but formed part of the interior design by providing quite a spectacle of natural light. 1N° 1000mm diameter SunPipe was installed to the central Library and this in itself forms a focal point of a flood of natural light to this area, which draws comment and praise from many visitors to this rather unique institution in the middle of Abu Dhabi.

37Case Studies

Latifa School for Girls & Rashid School for Boys DubaiEven in Dubai they have seen the benefit of Monodraught SunPipes, not only to counteract the strong power of the Middle East sun but also to bring in the benefits of filtered natural sunlight to school children without the attendant problems of glare and heat gain. By using SunPipes, the window blinds can be kept firmly shut and the electric lighting can be kept off! Monodraught’s Middle East office provides a complete supply and fix service using our own Dubai based installation teams to provide a fast and highly successful installation service.

Worldwide Interest

Monodraught SunPipes have now penetrated virtually every country throughout the world. The unique faceted Diamond dome transmits more light than any other system and the wide range of 10 different sized SunPipes from 230mm to 1500mm diameter makes SunPipes the universal choice. There is virtually no limit to the application of SunPipes and since no two Projects are the same, Monodraught’s Design Department will produce bespoke designs for any Project.

Polycarbonatediamond top dome

3 piece ceiling diffuser

Mirror finish aluminium tube with 98% reflectance

38

The detailed monitoring and measurements were carried out over four days in August 1998. The external temperatures were approximately 29°C, for two of the days. On the other two days ranged from 18°C to 22°C.

The ventilation rates of the lecture theatres with the Windcatchers closed and sealed was determined to find a base comparison. Readings were also taken with the dampers closed and fully open and were measured on three

days in G105 and four days in G111. The effect of night cooling from the units was also determined over two days. Flow visualisation studies were undertaken on the units using smoke as a tracer. A recording of these tests were made on videotape.

It was determined that the background ventilation of both lecture theatres (i.e. Windcatchers sealed) was relatively low. With the Windcatchers fully open the ventilation rate in G105

ranged from 1.24 ac/hr at 1.7 m/s wind speed to 5.2 ac/hr at 4.5 m/s. For G111 it ranged from 2.13 ac/hr at 2.6 m/s to 4.68 ac/hr at 4.1 m/s.

Ventilation measurements were carried out in both lecture theatres using the tracer gas decay method, Sulphur Hexafloride (SF6).

Three pairs of small mixing fans mounted in opposing directions in stands were placed far apart in both lecture theatres. The purpose of the fans was to mix the incoming fresh air with the tracer gas inside the lecture theatre.

Putting Windcatchers to the test

The University of Hertfordshire was the test site and used two Lecture Theatres that had been converted from what was originally its old mainframe computer room. There were no openable windows in either Lecture Theatre. G105 was the smaller of the two with a volume of 458m3. G111 had a volume of 769m3.

A 4-day on site investigation carried out in August 1998 by the Building Research Establishment on two Lecture Theatres at the University of Hertfordshire at Harlow proved the effectiveness of the Monodraught Windcatcher system under summer load conditions.

The BRE Tests determined that there was no short circuiting of airflows at any time and the air change rates were measured with the monitoring equipment being placed in the furthermost corners of the Lecture Theatre in each case and recorded air change rates of up to 5.2 ac/hr despite external temperatures of up to 29°C which is considered to be an excellent result.

Left: Flow visualisation of moderate wind speed with no evidence of any "short circuiting" of the air movement

BRE Testing

39

Other Universities and Test HousesWork has also been carried out at Loughborough University and UMIST, as well as at BRE and BSRIA on the application of Windcatcher natural ventilation systems. Full copies of all these Reports are available on request from Monodraught

Carbon Trust and DTI AwardsTwo major funding awards were made to Monodraught in 2006 to research PCM (Phase Change Materials) and Evaporative & Desiccant cooling in conjunction with Nottingham University. As a result, Monodraught’s new Cool-phase system has been launched.

A 4-year Research Programme is being carried out in conjunction with Brunel to investigate indoor environmental

conditions on a wide range of Projects including Schools, Colleges, and Universities to Building Society offices throughout the UK. Buildings are being assessed both before and after Windcatchers and SunPipes have been installed and full Reports will be available on request.

A 3-year Research Programme has been undertaken to study

and assess the potential of solar powered air conditioning, to be used in conjunction with the Monovent system and to establish the viability of an energy free cooling system.

Liverpool University, Loughborough University and UMIST have all been

closely involved with research into Monodraught products and various Papers have been published.

Professor Mike Wilson has considered a number of systems with Monodraught but specifically a

composite lighting unit that incorporates a standard SunPipe with LEDs embedded into the surround. A solar panel at roof level would connect a solar battery and this would provide 24 hour lighting. A prototype is under construction.

Monodraught have implemented a very active Research and Development Department at their offices at Halifax House in High Wycombe and are also working closely with a number of Universities in the UK. A group of six full-time dedicated R&D Engineers are exploring every avenue of renewable energy features at Halifax House, where a total of 45 SunPipes and Windcatchers are installed at the offices are constantly monitored on performance.

Monodraught have a permanent Environmental Test Chamber there to carry out the continuous

assessment and development of SunPipes and all their associated components. A 3-year Research Programme is being undertaken. A Monodraught SunCatcher and SunPipe system is also installed at the Eco House at Nottingham University, which was completed in 2001, and is also being constantly monitored.

A 2-year Study was carried out to develop a computerised prediction model, as shown, to assess the

transmittance of daylight by lux plots into the interior of buildings. Further advice on light output is always available from Monodraught Head Office.

LONDONmetropolitan

university

NAPIER UNIVERSITYEDINBURGH

BrunelUNIVERSITYW E S T L O N D O N

THE UNIVERSITY OF LIVERPOOLINVESTING IN KNOWLEDGE

Choking risks to childrenGOVERNMENT CONSUMER SAFETY RESEARCH

under four from toys and other objects

Department of Trade and Industry

Our commitment to R&D

Monodraught supports a number of Research Programmes being carried out to ensure that their products maintain a continual development cycle that can be monitored and independently assessed by the Universities. Furthermore, Monodraught considers it has a commitment to supporting and encouraging new Engineers to the industry to engross themselves in these new sustainable developments that may hold the key to so many of our dilemmas for our future energy usage.

R&D

Monodraught Windcatchers

have proved to be the most

effective method of providing

natural ventilation to any

commercial building.

‘‘’’National Green Specification

Part of the VKR Group

The Danish based VKR Group's mission is to bring daylight, fresh air, solar energy and a better environment into people's everyday lives. VKR Holding is the parent company of the VKR Group and owns brands such as VELUX roof windows, VELFAC and Rationel vertical windows as well as WindowMaster and European thermal solar companies.

Other brochures available

passive cooling system

Cool-phase Brochure FINAL -06-10-08.indd 1

06/10/2008 10:44:12

Solar powered ventilation and natural daylight

from rooftop...to bathroom!

by Monodraught

April 2007

April 2007

Winner of the Interbuild 2006

"Best Interior Product of the Show"

Sola-vent landscape April 2007 w4 4

25/04/2007 09:31:34

MAY 2006

Natural daylight where windows can't reach

by Monodraught

Natural Ventilation Systems

March 2007

Windcatcher Brochure FINAL PRES2 2

13/03/2007 13:52:43

Windcatcherboost Energy free

powered ventilation

Patent Application Number: 0523033.9

NBS Specification

Winner of the Interbuild 2006

" Best Building Services Product of the Show"

and Finalist of Air Movement Product of the year 2007

April

200

7

FINALIST

Sola-boost with ABS FINAL PRINT 4 4

28/03/2007 14:14:04

Halifax House, Cressex Business Park, High Wycombe, Buckinghamshire HP12 3SE

Tel: 01494 897700 Fax: 01494 532465email: [email protected] www.monodraught.com

Febr

uary

200

9

• Austria • Belfast • Dubai • Glenrothes, Scotland • Manchester • Brasov, Romania • Sydney • St Lucia

Professor Payne has made an outstanding

contribution to the field of natural

ventilation, passive cooling and daylighting

and his pioneering work on Windcatchers

and SunPipes has transformed the industry.

‘‘’’Professor Saffa Riffat - University of Nottingham