‘Why Automate Windows’ Part 1. ‘Fresh Air & Actuators’ Will Perkins – Managing Director – SE Controls

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In this series of articles by Will Perkins we look at the provision of adaptive natural ventilation for healthy and efficient buildings and the safety provision of smoke ventilation. The series attempts to explain some of the pitfalls in the lack of early design and understanding of such systems.

One of the main reasons to automate windows is that of convenience. Not all windows are located at reachable height and may need a pole to operate, in some larger rooms and corridors many windows may need to be opened, so clearly an automated solution is preferable. On securing premises in the evening, automated systems can ensure all windows are closed prior to setting alarm systems. Other benefits can include ‘night time cooling’ strategies, when premises may not be occupied, and an automated solution can operate above ground windows on a time switch basis.

The integration of automated windows into a complete building management system can ensure the most efficient use of energy. Many of BREEAM excellent rated projects in the UK today use natural ventilation strategies based on window automation.

But why do we need to ventilate our buildings? According to Approved Document F and CIBSE it is mainly for health reasons offering the occupiers appropriate Indoor Air Quality (IAQ). Inadequately ventilated buildings can harbour such gases as radon, a naturally occurring gas in the earth, hydrogen sulphide, which often results from the bacterial breakdown of organic matter in the absence of oxygen, carbon monoxide, by combustion processes, dust, virus and fungal spores. The presence of any of these elements can prove to be the cause of ‘sick building syndrome’.

Today we are also much more aware of VOC’s  (Volatile Organic Compounds), which have significant vapour pressures which can  affect the environment and ultimately human health. In newly fitted buildings VOC’s are often present in high quantities in materials such as setting paint and new carpets, these ‘smells’ can easily be identified in the atmosphere. Whilst many are non-toxic at the levels present, VOC’s can still have chronic effects on health. Today anthropogenic VOC’s are tightly regulated, particularly in materials used indoors, but ventilation strategies can play a big part in negating the risk.

In busy buildings, body odour, an increase in moisture from breathing and build-up of CO2, often leads to lethargic working or learning environments, resulting in poor working performance – this issue has been well documented in schools where an ‘appropriate indoor air quality’ is crucial to learning ability.

It is crucial that the ventilation strategy is decided at the outset of the design process. By adopting either a completely natural ventilated solution or a hybrid mixed mode solution with mechanical cooling for in only the harshest of weather conditions, can significantly reduce a buildings running costs.

So we have covered the practical reasons and the need for ventilation in our buildings today, but how do we achieve the ‘automation’?

A window ‘actuator’ is usually an electrical device which is placed on the leading edge of a window to open and close a window to various degrees as required. These come in two basic types, a ‘chain’ actuator and a ‘linear’ actuator. Chain actuators are the most compact and operate by pushing a one way folding chain out from a flush motorised housing fitted to the frame or opening light. In areas where windows are much larger, linear actuators, based on fixed ‘screw’ and motor principle may be used.

Whilst these devices may seem to be simple, window actuators do come in a very wide range of sizes and typical offer the following choice specification:

Voltage: Either in 24V DC or mains 230V AC ratings. Where smoke control is required 24V DC actuators are used so that these can be operated from an independent battery back-up in case of fire and power outage in the building.

Load: Usually indicated in amperage and is very important to consider when specifying a complete system. Often cheaper units are less efficient and require greater loads which results in an increase of control panels to operate at the higher amperage, not to mention the increased energy requirements.

Force: Indicated in Newtons (9.81 N = 1Kg) and required to open and close the window safely in all weather conditions. Referring back to efficiency, the available force within the unit should be as efficient as possible to reduce the amperage required. Some larger windows may need two actuators to perform correctly.

Stroke: This is the distance the actuator travels creating the safe opening of the window normally indicated in millimetres.

Speed: Indicated in millimetres per second. This is an important consideration in smoke ventilation situations where smoke vents must fully open with a 60 second time limit.

Size: Units vary in size depending on their specification but housings are very important to be considered when looking at the space available within the reveal, the size of the vent and the stroke required.

Intelligence: Some basic actuators rely on simple switches to limit and run the actuator motor, where occupant intervention is required. Some more sophisticated devices offer resistance feedback and information on where the actuator is within its cycle by the use of incremental volt measurement.

The most important aspect of all these variables is getting the right actuator in the right place to do the job most effectively with the minimum of maintenance. As mentioned earlier it is crucial to get a specialist involved at the very early design stages to determine the most efficient product and designs available. Leaving the choice of actuator to the lowest common denominator – cost, can have a serious detrimental impact on an installations performance and  on-going maintenance requirements.

In the next article we will cover free area calculations guidance under the new Approved Document B 2007, and how to achieve this effectively and safely.

SE Controls operate across the globe with offices in several continents, with specialists offering clients expert advice based on local legislative requirements. Visit the website at www.secontrols.com for further information. To discuss your requirements with SE Controls, or request literature, please call their head office in Lichfield on 01543 443060.

Focus on waste management and recycling pays off for SE Controls

An ongoing programme of effective waste reduction, management and recycling by Staffordshire based smoke control and natural ventilation solutions specialist, SE Controls, has enabled the company to ensure that none of its waste goes to landfill sites.

 

Since mid 2008, SE Controls has partnered with commercial waste management and recycling business, Briers, to not only reduce the level of waste it produces, but to also improve the efficiency while increasing the proportion of waste material that could be recycled.

 

In addition to metals, plastic, paper and cardboard waste produced by the company from its day to day operations, a proportion of the SE Controls waste is made up of electronic components and equipment, which is managed in compliance with WEEE regulations.

 

Mark Soleil, SE Controls’ operations Director, explained: “All businesses have an obligation to meet the minimum standards for waste management, but at SE Controls, we’re always looking to reduce our waste material and its impact on the environment, as well as reducing our packaging waste costs.”

 

He added: “Our partnership with Briers has proven to be highly productive and we have worked together closely. Their high quality recycling solutions coupled with our focus on reducing scrap and waste has enabled us to achieve our present situation where no waste from our UK operations is sent to landfill.”

 

SE Controls specialises in the design, project management and installation of advanced smoke ventilation and natural ventilation solutions to meet the needs of architects, contractors, building services engineers and facilities managers worldwide. Further information on SE Controls’ products, solutions and projects can be obtained by visiting www.secontrols.com or calling +44 (0) 1543 443060.

SE Controls tops £12,000 in Macmillan charity fundraising

A year long fundraising initiative by employees at Midlands based smoke and natural ventilation specialist, SE Controls, has generated more than £12,000 for national cancer support charity, Macmillan.

 

Macmillan Cancer Support was chosen by SE Controls after the company’s Commercial Manager, Mark Hargreaves, initially nominated the charity as a worthy cause and fellow employees voted overwhelmingly to select Macmillan as its ‘charity of the year’ for 2011.

 

During the year every opportunity was taken by SE Controls staff to raise money for the charity, using numerous initiatives ranging from a wacky Duke & Duchess Cambridge inspired Royal Wedding Fancy Dress and cake baking competition to a marathon 127 mile sponsored bike ride and the setting up of an ongoing book lending library at the company’s Staffordshire head office.

 

“The support from everyone has been phenomenal,” said a delighted Mark Hargreaves who recently presented the final donation cheque with SE Controls’ MD, Will Perkins, to Macmillan’s Hilary Barnes and corporate fundraiser, Sue Allcock.

 

He continued: “ It’s amazing what can be accomplished when people pull together to help support charities, such as Macmillan and I’m particularly proud of our fundraising achievement, which we hope to be able to repeat with our nominated charity for 2012.”

 

Macmillan’s Sue Allcock added: “What SE Controls has achieved is absolutely marvellous and is greatly appreciated not only by us, but also by those who rely on Macmillan for care and support at an extremely difficult and challenging time.”

 

 

 

SE Controls specialises in the design, project management and installation of advanced smoke ventilation and natural ventilation solutions to meet the needs of architects, contractors, building services engineers and facilities managers worldwide. Further information on SE Controls’ products, solutions and projects can be obtained by visiting www.secontrols.com or calling +44 (0) 1543 443060.Image

Triple RIBA Stirling Prize success for SE Controls

The hotly contested 2011 RIBA Stirling Prize has resulted in a triple success for SE Controls as its specialised smoke and natural ventilation solutions are used not only in Zaha Hadid’s stunning award winning design for Brixton’s Evelyn Grace Academy, but also in two of the other five shortlisted finalists.

The Evelyn Grace Academy incorporates four separate schools within a single building and to ensure that high levels of natural light are available throughout the building, the exterior makes full use of glass cladding, which forms part of the natural heating and ventilation incorporated within the design.

Control and management of natural ventilation system’s concealed vents is handled by more than 70 SE Controls OS2 Controllers linked to the building management system (BMS) to provide incremental operation of the vents to ensure ample fresh air is supplied at all times throughout the building.

Natural ventilation also forms part of the SE Controls’ solution installed at another RIBA Stirling Prize finalist, the new Royal Shakespeare Theatre in Stratford upon Avon. SE Controls provided the smoke and natural ventilation strategy in the rebuilt restaurant area, the colonnade and the link bridge connecting the building to a newly built
observation tower.

The multi-zone smoke and natural ventilation solution developed and installed for the RSC theatre by SE Controls utilises a range of EN12101-2 chain actuators connected to dedicated zone control panels as part of the fire alarm system and linked to the building’s BMS. The natural ventilation solution is also linked to the smoke ventilation system to clear smoke and enable visitors to evacuate the building in the event of a fire.

Darren Wainwright, SE Controls’  Project Leader, commented: “These two projects, together with our involvement in the Olympic Velodrome, reinforce the important role that effective smoke and natural ventilation play in modern architecture. While we might not provide the vision for these outstanding pieces of architecture, our role is to ensure that the ventilation and building safety needs meet the demanding specifications and I’m delighted that we have been involved in these three unique buildings.”

SE Controls specialises in the design, project management and installation of advanced smoke ventilation and natural ventilation solutions to meet the needs of architects, contractors, building services engineers and facilities managers.

Advanced smoke ventilation solution from SE Controls protects Nottingham students

A £55 million student accommodation development in Nottingham is using integrated smoke and heat exhaust ventilation systems from SE Controls to provide smoke free
escape routes for around 1000 students living in the new purpose designed apartments at Chettles Yard.

To meet the fire safety and smoke ventilation needs in three of the new buildings at the Chettles Yard development, SE Controls developed specific smoke and heat ventilation
solutions for each accommodation block based around its versatile SHEVTEC®
system.

Dedicated extended travel distance escape solution

As the maximum escape travel distance in two of the apartment buildings was within the 7.5 metre limit covered by Approved Document B of the Building Regulations, the SHEVTEC Natural Corridor Ventilation System was installed. However, the six storey F Building had a travel distance of 12.0 metres so SE Controls created a dedicated fire engineered solution around its LABC approved SHEVTEC Extended Travel Distance System.

In the event of a fire, the main exit route is through a singe protected stairwell, so the SE Controls solution had to provide high integrity smoke and heat ventilation that not only allowed occupants to travel the increased distance to safety, but must also perform at least as well as the code compliant systems installed in the other two accommodation blocks.

Fully compliant smoke ventilation system

The extended travel system used in Building F was originally developed by SE Controls using advanced computational fluid dynamics (CFD) to create an off the shelf, fully compliant and CE marked solution that can not only assist escape but also simplify the building’s design by removing the need for additional escape stairs.

In addition, the size of the smoke shafts used can be reduced to less than half of the 1.5m2 required under a typical natural ventilation system. When combined with the requirement for only one escape stair, this allowed the developers to incorporate more apartments within the building’s envelope.

The SHEVTEC system uses a dual smoke shaft and fan ventilated solution linked by smoke sensors through SE Controls’ powerful OSLoop® control system, which when triggered determines which shaft is closest to the fire and automatically opens the smoke shaft doors on each floor to extract smoke away from escape routes, corridors and stairs. Once actuated, OSLoop continues to monitor the entire system throughout the incident to ensure the system maintains its performance in accordance with the imminent EN12101 part 9 standard.

Fully managed turnkey project

SE Controls provided a full turnkey solution to the Chettles Yard development, involving project management, the supply and installation of the SHEVTEC system and liaison with all the appropriated authorities and inspectors, as well as full testing and rigorous commissioning procedures to verify the system’s performance, operation and compliance with the design brief.

Will Perkins, SE Controls’ Managing Director, explained: “This is an ideal example of how we combine our technical expertise, immense experience and innovative products to develop an outstanding solution on a challenging project.”

He added: “Chettles Yard itself is an incredibly innovative development and is providing much needed high quality accommodation for students at Nottingham and Trent Universities and I’m delighted that we have been able to play a key role in maintaining their safety.”

Further information

A fully detailed PDF case study covering the specific fire engineered smoke ventilation solution installed by SE Controls is available for download from the company’s website at www.secontrols.com/library.

SE Controls specialises in the design, project management and installation of advanced smoke ventilation and natural ventilation solutions to meet the needs of architects, contractors, building services engineers and facilities managers worldwide. Further
information on SE Controls’ products, solutions and projects can be obtained by visiting www.secontrols.com or calling +44 (0) 1543 443060.

http://www.secontrols.com/tv/video/smoke-ventilation-in-residential-buildings 

Natural Ventilation Strategy for Highbury College

Highbury College, located in Portsmouth, is a fine example of how our modern colleges should look and perform. Proud of their status as one of the highest achieving colleges in the area, the college has seen a multi-million pound investment in recent years and can now boast ownership of some of the most sustainable buildings in Portsmouth.

SECO 20 Chain Actuators’, from SE Controls were specified to form part of the natural ventilation system being installed into the main building. These actuators have a proven long life expectancy and have been used extensively in window automation requirements on many UK projects. In total 82 actuators are linked back to the buildings BMS which maintains air quality and temperature within the classrooms and main communal areas of the college.

SE Controls were specified on the project as they were recommended by the window specialist, the SECO 20 Chain Actuator provided a low power drain on the BMS system as compared to other actuators currently available. By choosing low amperage actuators, cost savings can be made both in the fixed hardware required for control and save energy requirements over time.

The project required SE Controls to install the actuators on site and ensure that they were commissioned ready to be wired into the BMS system by others. Whilst SE Controls can offer a wide range of services from design through to installation and on-going maintenance, the flexibility of the services provided allows the company to quote for any window automation requirements and to closely liaise with other specialists on site.

SE Controls supply window actuators and sophisticated control systems to cover both natural ventilation and smoke control strategies. SE Controls is a
UK based company operating across the globe with offices in several continents
and regional specialists offering clients expert advice based on local legislative requirements, visit the website at www.secontrols.com. To discuss possible project requirements with SE Controls and request literature, please call their head office in Lichfield on 01543 443060.

Placing SE Controls on the Map

Completed early this year, the new Ordnance Survey headquarters in Southampton is one of a growing number of office buildings meeting the demand for high levels of energy savings. An adaptive natural ventilation solution was specified from SE Controls, which works in conjunction with other low energy systems and has ultimately led to the building being awarded a BREEAM ‘Excellent’ rating.

The new Ordnance Survey headquarters consists of a large three storey atrium with four buildings attached in an array of ‘fingers’ to the East of the the development.
To capture natural light, each of the ‘fingers’ has large areas of North facing
curtain walling, installed with opening lights. To the South, the envelope
consists of few opening windows in a white cladded facade to reduce the
incidence of solar heat gain.

Adaptive natural ventilation is provided by the top hung windows to each of the three floors together with the provision of six ‘chimneys’ within the office complex.
These ‘chimneys’ funnel the air rising from the atrium and drawing air from the
three floors, expelling it from the building, whilst fresh air is drawn in
through the windows. By utilising temperature and CO2 zoned sensors across each of the office floors, windows can be automatically and precisely opened to
ensure optimum levels of fresh air are provided. The adaptive natural ventilation system is integrated within the Building Management System (BMS) to
ensure that heating, cooling and lighting requirements work together in an
optimal manner which in turn ensures low energy consumption.

Together with the adaptive natural ventilation provision, the building is heated and cooled, when required, by a large array of boreholes coupled to a
ground-sourced heat-pump system. Furthermore rainwater is harvested for
flushing toilets and landscape irrigation in dry conditions. Large North facing
curtain wall facades offer high levels of internal illumination and is balanced
with supplementary lighting, which has also been optimised to match daylight
sources. Sensors ensure that supplementary lighting switches off automatically
when not required. Other initiatives include a large composter to recycle all
kitchen waste on-site and the planting of a further 375 trees to supplement the
adjacent woodland.

Greg Tumilty, Senior Manager at the Ordnance Survey headquarters comments, “The facilities offered by the new building are impressive. Staff now have the perfect place to work and hold meetings in a light, and well ventilated space, it’s a far cry from our old offices, and too early to tell if the systems are running at their optimum capability at the moment, but we are gathering on-going information from the BMS which we can adjust to maintain and improve efficiencies in the future. We are all proud to be working in one of Southampton’s’ most impressive and sustainable buildings”

In total, 480 No. ‘TGCO 24 30 ED  chain actuators with soft close’ were fitted to 480 top hung, open out windows, these in turn are wired up in banks of no more than 6, to 105 No. OS2 control panels and switches. These control panels are in turn wired into one of three LON Networks, 1 on each floor, which are coupled to the BMS system.

Each bank of automated windows  are operated on a voltage signal from the BMS which is rated between 0 and 10 volts, each volt represents 10% opening of the windows in the bank. This way, small increments can be made in the window opening to ensure that ventilation conditions are always kept at an optimum.

Whilst the adaptive natural ventilation installation at Ordnance Survey headquarters was commissioned by SE Controls in the normal manner to meet a set specification, the systems installed are capable of data capture over time. This way, installed systems can be monitored and measured for various outside weather conditions and internal occupancy. These measurements can then be fed back into the automated system to ensure optimum and efficient performance.

As our new buildings become ever more energy efficient with effective and sustainable systems, an adaptive natural ventilation strategy is key to achieving air quality to meet the requirements of building occupiers. As in the design of the Ordnance Survey headquarters, only by considering all these systems at early design stages can they fully integrate and provide efficient and sustainable
buildings needed for our low carbon future.

SE Controls is a UK based company operating across the globe with offices on
several continents and regional specialists offering clients expert advice
based on local legislative requirements. Visit the website at www.secontrols.com for further information about the company. To discuss possible project requirements with SE Controls, or request literature, please call their head office in Lichfield on 01543 443060.

http://www.secontrols.com/tv/video/why-use-a-standalone-adaptive-natural-ventilation-system

Eight Core Competencies to Successful Smoke and Natural Ventilation Solutions

Despite companies promoting systems, products and services that are claimed to be ‘sustainable’ one thing is clear, a complete package aimed at getting the best
performance possible is crucial in choosing a partner for window automation.

SE Controls have 30 years experience in providing turnkey solutions to the
construction industry and pride themselves as being one of the most influential
smoke and natural ventilation companies in the UK.  To deliver a total solution for the
construction industry, whether for adaptive natural ventilation or smoke
ventilation
, companies at the top of their field must be able to provide these
eight core competencies:

Design

Early consultation with an experienced smoke and natural ventilation specialist is
vital to ensure that automatic opening vents are in the right place, and are of
the right size, to offer optimum performance with either natural ventilation or
smoke control requirements. Specialists must be competent in the use of
Computational Fluid Dynamics software and use this to effectively model
proposed designs and show optimal design solutions.

Manufacture

To use the latest methods of manufacture, the latest materials, and the most up to
date technology. In a rapidly changing world, this is the only way to produce
products that are fit for todays advanced buildings. Products that use less
power in operation are more efficient and as a result more sustainable. Pushing
the technology to its current known limits ensures that products continue to
evolve. Above all quality control and rigorous testing of all products before
they go into service is crucial to keeping maintenance costs at a minimum.

Distribution- Stock management

A ‘state of the art product’ is no benefit if it is not available, so stock
control and keeping the ‘right’ stock is important to meet demand. Also
important is product availability at short notice, when products need to be
replaced through damage or misuse. Detailed order tracking further improves
service by keeping customers fully informed of an orders progress and when it
is due to be delivered.

Ultimately product availability is a crucial element in achieving customer satisfaction.

Project Management

Early involvement from a smoke and natural ventilation specialist in a project has shown to save considerable time and costs further down the building project
timeline. A single Project Manager must always be nominated to control all
aspects of the project as the coordination of an efficient and effective
ventilation solution involves many building specialists. This will ensure that
the right products, of the right specification, are delivered at the right time
and are in the right place.

Installation

Skill and experience is required to ensure that a window actuators are fitted
correctly and offers a long and trouble free life. But to ensure that the
automation provides the very best in natural ventilation or smoke control
provision, experienced on-site engineers are required to complete and
commission the installation to meet the specification.

SE Controls’ Engineers are some of the best trained and experienced in the
industry, offering competent advice and solutions to on-site conditions.
Covering the whole of the UK, engineers with considerable experience in all
building types and are always on hand to offer the very best advice.

Commissioning

To ensure designed systems meet with the specification laid down at the design
stages, all systems must be commissioned. Not just switching on and ensuring
everything is linked together properly, but by running scenarios through the
designed system to imitate climatic changes and possible requirements for smoke evacuation.

A specialist team must ensure that the system is fit for purpose and sign it off
for handover to the client of main contractor.

Maintenance

Whilst a well-designed product will last a long time, in the real world there are
times products and systems can be abused. This causes failure and regular
maintenance of systems will ensure that buildings continue to perform for many
years. In the case of smoke control, preventative maintenance is crucial to
offering safe places to work, live and play. Preference should always be given
to the manufacturer and designer of the system to provide maintenance.

Complete understanding of an installation helps to maintain it to its original design specification.

Training

People Matter – so important in any business, but initial and on-going training of
staff ensures that correct solutions are provided as first solutions. The same staff offers specifiers CPD training to ensure that natural ventilation and smoke
control systems and solutions are exploited to their best advantage by some of
the top designers in the UK. Experienced staff can offer the correct guidance
and in turn earn respect from specifiers and clients.

Regular training, with measured results, offers staff a pride in their work and results in a better motivated workforce, high class workmanship and ultimate customer satisfaction.

SE Controls clearly define these eight core competencies and use key performance indicators to monitor and improve services. Importantly each of these core competencies overlap and work together to offer an unparalleled level of service from the UK’s leading smoke and natural ventilation provider.

SE Controls is a UK based company operating across the globe with
offices on several continents and regional specialists offering clients expert
advice based on local legislative requirements. Visit the website at www.secontrols.comfor further information about the company or to discuss possible project requirements with SE Controls, please call their head office in
Lichfield on 01543 443060.

Why Automate Windows-Part 1. ‘Fresh Air & Actuators’

One of the main reasons to automate windows is that of convenience. Not all windows are located at reachable height and may need a pole to operate, in some larger rooms and corridors many windows may need to be opened, so clearly an automated solution is preferable. On securing premises in the evening, automated systems can ensure all windows are closed prior to setting alarm systems. Other benefits can include ‘night time cooling’ strategies, when premises may not be occupied, and an automated solution can operate above ground windows on a time switch basis.

The integration of automated windows into a complete building management system can ensure the most efficient use of energy. Many of BREEAM excellent rated projects in the UK today use natural ventilation strategies based on window automation.

But why do we need to ventilate our buildings?

According to Approved Document F and CIBSE it is mainly for health reasons offering the occupiers appropriate Indoor Air Quality (IAQ). Inadequately ventilated buildings can harbour such gases as radon, a naturally occurring gas in the earth, hydrogen sulphide, which often results from the bacterial breakdown of organic matter in the absence of oxygen, carbon monoxide, by combustion processes, dust, virus and fungal spores. The presence of any of these elements can prove to be the cause of ‘sick building syndrome’.

Today we are also much more aware of VOC’s  (Volatile Organic Compounds), which have significant vapour pressures which can  affect the environment and ultimately human health. In newly fitted buildings VOC’s are often present in high quantities in materials such as setting paint and new carpets, these ‘smells’ can easily be identified in the atmosphere. Whilst many are non-toxic at the levels present, VOC’s can still have chronic effects on health. Today anthropogenic VOC’s are tightly regulated, particularly in materials used indoors, but ventilation strategies can play a big part in negating the risk.

In busy buildings, body odour, an increase in moisture from breathing and build-up of CO2, often leads to lethargic working or learning environments, resulting in poor working performance – this issue has been well documented in schools where an ‘appropriate indoor air quality’ is crucial to learning ability.

It is crucial that the ventilation strategy is decided at the outset of the design
process. By adopting either a completely natural ventilated solution or a
hybrid mixed mode solution with mechanical cooling for in only the harshest of
weather conditions, can significantly reduce a buildings running costs.

So we have covered the practical reasons and the need for ventilation in our buildings today, but how do we achieve the ‘automation’?

A window ‘actuator’ is usually an electrical device which is placed on the leading edge of a window to open and close a window to various degrees as required. These come in two basic types, a ‘chain’ actuator and a ‘linear’ actuator. Chain actuators are the most compact and operate by pushing a one way folding chain out from a flush motorised housing fitted to the frame or opening light. In areas where windows are much larger, linear actuators, based on fixed ‘screw’ and motor principle may be used.

Whilst these devices may seem to be simple, window actuators do come in a very wide range of sizes and typical offer the following choice specification:

Voltage: Either in 24V DC or mains 230V AC ratings. Where smoke control is required 24V DC actuators are used so that these can be operated from an independent battery back-up in case of fire and power outage in the building.

Load: Usually indicated in amperage and is very important to consider when specifying a complete system. Often cheaper units are less efficient and require greater loads which results in an increase of control panels to operate at the higher amperage, not to mention the increased energy requirements.

Force: Indicated in Newtons (9.81 N = 1Kg) and required to open and close the window safely in all weather conditions. Referring back to efficiency, the available force within the unit should be as efficient as possible to reduce the amperage required. Some larger windows may need two actuators to perform correctly.

Stroke: This is the distance the actuator travels creating the safe opening of the
window normally indicated in millimetres.

Speed: Indicated in millimetres per second. This is an important consideration in smoke ventilation situations where smoke vents must fully open with a 60 second time limit.

Size: Units vary in size depending on their specification but housings are very
important to be considered when looking at the space available within the
reveal, the size of the vent and the stroke required.

Intelligence: Some basic actuators rely on simple switches to limit and run the actuator motor, where occupant intervention is required. Some more sophisticated devices offer resistance feedback and information on where the actuator is within its cycle by the use of incremental volt measurement.

The most important aspect of all these variables is getting the right actuator in the right place to do the job most effectively with the minimum of maintenance. As mentioned earlier it is crucial to get a specialist involved at the very early
design stages to determine the most efficient product and designs available.
Leaving the choice of actuator to the lowest common denominator – cost, can
have a serious detrimental impact on an installations performance and  on-going maintenance requirements.

In the next article we will cover free area calculations guidance under the new
Approved Document B 2007, and how to achieve this effectively and safely.

SE Controls operate across the globe with offices in several continents, with
specialists offering clients expert advice based on local legislative requirements. Visit the website at www.secontrols.com for further information. To discuss your requirements with SE Controls, or request literature, please call their head office in Lichfield on 01543 443060.

New naturally ventilated wing to Kew’s Herbarium

Since the Royal Botanic Gardens, Kew’s Herbarium, Library, Art and Archives was first founded in 1852, much has changed in the world of plant classification. Until a few decades ago only the physical appearance of plants guided how taxonomists classified species. Today, genetic analysis enables scientists to reassess ideas of relatedness of plants, and also to deduce the order in which groups of plants diverged from each other as they evolved.

Kew’s Herbariumis expanding during the United Nation’s International Year
of Biodiversity with a new state-of-the-art 5000m² extension. Kew will take
advantage of the additional space provided by the new wing to reorganise its
collection of plant specimens to conform to the DNA-based Angiosperm Phylogeny Group (APG) system of classification.

Designed by Edward Cullinan Architects, the new wing was carefully designed to complement the existing building and go on to say “The concept for the building is generated by juxtaposing the vault-like, climate-controlled archive (that keeps the specimens at a constant 15°) with airy, day-lit research spaces.
These glass and timber research areas undulate around the 3 storey, brick-clad
archive enabling scientists to work in close proximity to the collection.”

To ensure that the research spaces within the new wing are kept well ventilated, adaptive natural ventilation specialists SE Controls were specified to provide
automation to the windows and roof vents.

Adaptive natural ventilation is a solution offering the best air circulation with much lower energy input compared to mechanical ventilation plant. In its basic form it involves the installation of windows or vents in a building envelope that
open and shut automatically according to set parameters for the space within
the building. These parameters are usually based on indoor air quality, and temperatures, correct levels being essential to maximise concentration levels and thus productivity of occupants.

Adaptive natural ventilation is often coupled with smoke detection systems in modern buildings using the same vents and windows offering a positive saving on building costs. Natural ventilation systems are not just for new buildings.
Many existing buildings can easily be automated with little modification,
offering huge savings in energy costs whilst improving building comfort.

There are two main principles of naturally driven ventilation in buildings: the wind effect and the buoyancy or stack effect. Wind driven ventilation utilises wind pressures on an external elevation of a building to push fresh air inside. The buoyancy or stack effect is that of warm air rising drawing with it  stale air and leaving a low pressure  zone which in turn draws in fresh air through low-level open windows and dampers. Adaptive natural ventilation responds to internal and external conditions of a building using sensors & controls, and adjusting vent positions accordingly to maintain optimum conditions, thus adding value to the building by improving the  productivity of the occupants, which in real terms means a higher return on labour. Further interfaces with other building systems such as heating ensure energy losses are minimised, also giving cost savings during the life of the building.

Opening windows are designed into buildings to provide light, offer ventilation and give occupants a view out of buildings, as well as maybe providing smoke ventilation in the event of a fire. Windows may also be hard to reach or in a larger quantities too impractical to operate by hand. By motorising each window, a bank of windows can easily be operated from one place at one time.

To get the best possible natural ventilation solution it is best to design window
automation during the facade design either as a full natural ventilation system
or as a combined smoke and natural ventilation system. Well planned natural
ventilation designs can offer significant energy savings and therefore reduce a
client’scarbon footprint.

The importance of getting a specialist on board at an early design stage cannot be over stressed. By careful design at the early stages of building design, adaptive natural ventilation solutions will be more effective in use and more cost efficient overall, at contracting and operational stages.

Natural smoke ventilation utilises the inherent buoyancy of hot smoke, letting it rise and escape from the building whilst allowing cooler, heavier air, to enter at
low level into escape routes to allow safe exit for occupants or to aid in the
fire services entry into the building to the possible effected area. This is
achieved by introducing automatic vents at high level that open upon detection
of smoke, allowing the smoke to escape into the atmosphere.

Automatic opening inlet vents and windows at low level maintain the smoke reservoir at a safe level above head height to increase occupant’s visibility and ensure sufficient fresh air to survive during escape from a building.

On the new wing at Kew, SE Controls worked in partnership with the glazing specialist, Melayway Glass Assemblies Ltd. Schüco AWS systems were specified for the windows and doors, with FW60+ Curtain wall. All external finishes were specified and anodised by LHT to Uncol Anolok 541 ‘Pale Umber’. Internal finishes were specified in RAL 8080 matt powder coating.

For the roof lights, 24 no. ‘TGCO 24 20’, 250 mm stoke, chain actuators were fitted on bespoke brackets to provide both smoke control and natural ventilation.
Operated by a 24 volt supply, these actuators are provided with a battery backed controller connected to  a fireman’s override switch and to the fire alarm system, as well as the BMS.

Opening vents in the windows and curtain wall areas were fitted with SCCO 24 30 concealed actuators, approved for use with Schüco’s AWS 102 SK windows tested to EN12101-2 smoke ventilation regulations, again offering both smoke control and natural ventilation via the fire alarm and BMS. In order to provide manual override each zone of actuators have been provided with local open/close switches.

By working closely with the installer SE Controls have ensured that all power supply cables have been neatly concealed inside the aluminium curtain wall transoms and mullions. Cables are then gathered under the suspended floor void and then follow cable ducts to the control units. In total 24 independently controlled zones, or banks of automatic opening windows, are served by SE Controls equipment and are operated by a single control panel, complete with battery back-up.

Once installed, checked and commissioned, the installed system needs little
maintenance, unlike mechanical air conditioning systems. Preventative
maintenance is recommended at 6 monthly intervals to ensure that smoke control systems are fully operable in case of emergency, and can be combined with the glazing manufacturers’ recommended maintenance visits for windows, thus reducing overall maintenance costs. SE Controls Maintenance Division has been providing building owners with such services for nearly 30 years..

The original Kew Herbarium building has been extended six times, starting in 1877. The new wing extends the capacity of the Herbarium, Library, Art and Archives by about 40 years, providing climate-controlled storage and adjacent research areas.
As well as housing hundreds of thousands of plant specimens, it provides new,
state-of-the-art space for the Royal Botanic Gardens, Kew’s outstanding
Library, Art and Archives Collection. Scientists from other institutions and
amateur botanists will get greater access to the collections when the new wing
opens as part of the Royal Botanic Gardens, Kew’s year-long celebrations to
mark the UN’s International Year of Biodiversity.

The project engineers on the new Herbarium, wing are Buro Happold and construction services were provided by Willmot Dixon.

SE Controls offer a complete service of design, installation, commissioning and maintenance of smoke and adaptive natural ventilation control systems for any building.
Visit the website at www.secontrols.com for further information. To discuss a
requirement with SE Controls, or request literature, please call their head
office in Lichfield on 01543 443060.