"smoke and heat control systems"

A £52 million student accommodation development in Coventry is using smoke and heat exhaust ventilation (SHEV) systems from SE Controls to enhance fire safety by providing smoke free escape routes for almost 1000 students living at Paradise Student Village.

Berkeley Homes’ flagship Woodberry Park apartment development in North London is using an advanced smoke and natural ventilation system from SE Controls to not only provide protection for residents in the event of a fire, but to also create a better environment by actively managing any excessive heat build up in corridors.

OverviewKEA Dublin is a 2787m² shopping centre in Ballymun Ireland which required a full smoke ventilation system from Powrmatic.Project BackgroundIKEA Dublin is 30,000 square-foot shopping centre in Ballymun Ireland which required a full smoke ventilation system from Powrmatic.Project SolutionPowrmatic supplied 73 Roof Opensky smoke ventilators to the new IKEA store in Dublin. Specified and installed by Air Design Systems Ltd, the installation is providing full smoke ventilation to five separate areas within the store.The second area is the show room and café which were naturally ventilated by louvred ventilators and split into zones using a fixed smoke curtain. A similar approach was taken with the self-serve warehouse and checkout area, which was also naturally ventilated using louvred ventilators and fixed smoke curtains. Polycarbonate blades are used on the louvred ventilators to allow natural light to enter the spaces. Additionally, the escape staircases were ventilated using louvred ventilators at the head of the stairs and a local control panel with an emergency break glass.Project Result“We were involved from the very early in the design stages of the project, using our knowledge and experience of installations within other IKEA stores and warehouses to engineer a suitable, cost-effective solution,” recalled  Air Design Systems Ltd Director Alan Clare.“Within these works we have had to include for three separate main control panels, all electrical wiring run in fire-protected cable, local control panels with emergency break glasses and a mimic control panel linking all smoke ventilation zones. We also provided rain sensors, roof access hatches, and head of lift shaft cowls,” he added.Due to the success of the project, there was a requirement within a year of opening to extend the warehouse area. Air Design Systems Ltd was awarded the sub-contract to extend the system into the new space and link back to the existing control system. In total, a further 14 Powrmatic ventilators were installed in the warehouse roof & walls and at the head of the two additional emergency staircases.Powrmatic’s Roof Opensky ventilators are attractive, low-profile units that have been specifically designed for both smoke and heat exhaust and natural ventilation applications. The Opensky can be roof or wall mounted for exhaust or inlet and can be supplied with a hinged base for use as an access hatch. They are tested for use as smoke ventilators to BS EN 12101-2.

Project BackgroundDesigned by Pritzker Prize-winning architect Zaha Hadid in 2004, before London won the bid for the 2012 Summer Olympics, the London Aquatics Centre is an indoor facility with two 50-metre (160-foot) swimming pools and a 25-metre (82-foot) diving pool. Its iconic wave-like roof sweeps up from the ground and was inspired by the fluid geometry of water in motion, creating spaces and a surrounding environment in sympathy with the river landscape of the Olympic Park.Project SolutionPowrmatic Wall Opensky louvred ventilators were at the heart of the smoke and natural ventilation system at the London Aquatic centre in the Queen Elizabeth Olympic Park in Stratford, east London. The ventilation systems were designed and installed by Air Design Systems Ltd.The wall mounted Opensky louvred ventilators are used to provide a high-free area at the back of the stands for heat exhaust and smoke extract. The units were double-stacked and provided with a white polyester powder-coated finish.Air Design Systems Ltd also made provision for the control system that included local control panels, electrical wiring, override switches and full commissioning and demonstration of the system.Project ResultTested for use as smoke ventilators to BS EN 12101-2, Powrmatic’s Opensky ventilators can be roof or wall mounted for exhaust or inlet and can be supplied with a hinged base for use as an access hatch. They have been specifically designed for both smoke and heat exhaust and natural ventilation applications and combine an attractive style with a discreet, low profile.

A new ferry terminal on Brodick Bay, created as a tourism and community gateway to the Scottish Isle of Arran, has been fitted from stem to stern with door and window systems supplied by GEZE.Maritime design and modern comfortThe ship-shaped terminal, designed by the renowned architectural firm Norr of Glasgow, is part of a £30 million investment which aims to update the harbour, get it ready for 21st century travel, and improve passenger comfort.Natural ventilation thanks to automated windowsThe generously sized lounge with its double height and large wall of windows on the western façade offers visitors a breathtaking view of Brodick Bay. The large windows, which are automatically opened and closed by 30 GEZE Slimchain chain drives, give the reception area at the main entrance to the building a bright and spacious feel. The uniquely slim and understated look of the Slimchain window drives integrates perfectly into the unique façade design of the Brodick ferry terminal.The Slimchain window drives were installed not only on the large windows in the lounge, but rather throughout the entire two-storey building – with the exception of the upper ventilation openings: Powerchain chain drives are used there. These especially powerful window drives were chosen to operate the larger windows, since they allow for large opening widths – which is important for quickly venting smoke in case of a fire.The window drives are connected to a GEZE MBZ 300 SHEV control panel for smoke and heat extraction drives, which is integrated into the building management system of the terminal. This makes it possible to easily control and monitor the complex natural ventilation system.Ventilation, smoke and heat extraction, and emergency exit protectionThe windows in the staircases are also equipped with Slimchain chain drives. If needed, the window systems also allow for natural smoke and heat extraction: In case of smoke and heat, the smoke extraction solutions open the windows and control fresh air openings, so that lifesaving escape routes remain smoke-free and safe to use in case of an emergency. In addition, GEZE OL Line manual fanlight openers provide supplementary natural ventilation.Door systems for accessible fire protection doorsBeneath the glazed western elevation are two automatic swing doors to either side. These are powered by GEZE Slimdrive EMD-F door systems, just like another door on the side façade of the building. The electro-mechanical swing door drives for single leaf fire and smoke protection doors are extremely versatile: They provide power assisted opening and can be initiated using the operating button with constant opening and closing speed. Integrated obstacle detection also identifies potential obstacles and stops the opening or closing process if needed. By doing so, Slimdrive EMD-F drives also ensure easy and safe access for people with mobility issues.Understated design and high access convenienceFrom the main entrance, a glazed corridor leads to a bi-parting sliding door powered by a GEZE Slimdrive SL NTsliding door system, which leads into the foyer of the main reception area. The Slimdrive door drive fulfils two key stipulations here at once: It is suitable for interior and exterior doors with high levels of footfall, and ideally suited for glass façades with high design standards – such as the Brodick ferry terminal – due to its low operator height of just 7 cm.

Avantage MP AOVAvantage MP is a 1 and 2 hour fire resistant AOV smoke control damper suitable for multi compartment applications of smoke control such as lobby to smoke shaft ventilators.The product is based on a damper door design and has been tested and certified to BS EN12101-8 achieving 1 and 2 hour fire rating. This is particularly important so to maintain the fire integrity of any shaft.The Avantage AOV smoke control damper is noted for its superior airtight properties. The damper is available as a motorised version providing a practical solution for large buildings where fire safety equipment is regularly testedThe unit is completed with a decorative silver anodised aluminium grille on the front. It fixes into a fire compartment shaft wall and is direct fixed within the opening through the sides of the damper. Once the damper has been securely fixed to the structure any shaft side perimeter gaps must be caulked with intumescent sealing material.Recommended fixing details are available on request to suit an array of fire compartment walls together with safety, installation and maintenance instructions.The front face grille is fixed to the damper unit flange and has the option of being coloured black behind the grille for improved visual appearance. The grilles are attached with concealed fixings.Key featuresSuperior air tightness (tested at -1500 Pa)Minimal pressure dropImproved energy efficiency and acoustic insulationRemovable grille for easy maintenanceAuxiliary switches for remote damper position indicationEfficient robust decorative finishing grille with concealed fixingsThe wiring connection and the drive motor mechanism is accessed lobby side of the ventilator behind the decorative grilleEasy access for service and maintenanceWide range of sizes for optimal selection considering pressure drop and space available

This case study takes the reader through the need and requirements for providing and implementing a combined smoke and natural ventilation system for the City Academy, Hackney .

An iconic and popular residential development in the West Midlands, The Landmark at Brierley Hill, is using smoke control systems from SE Controls to ensure escape routes are kept free of smoke in the event of a fire, allowing residents to exit the building safely.

One of Manchester’s latest high rise residential developments, Cambridge Street, is using smoke control systems from SE Controls to provide a safe environment for residents, by ensuring escape routes are kept clear of smoke in the event of a fire.

The smoke ventilation system at Matlosana Mall, shopping and entertainment centre in Kerksdorp, South Africa is using SE Controls’ window automation and control panel solutions to ensure it operates perfectly in the event of a fire, allowing smoke-free escape routes to be maintained for shoppers and staff.

Sertus were commissioned to provide products that would help mitigate heat build-up within the common areas of the building.Project Name: Fulneck PlaceLocation: LondonSector: ResidentialClient: Breyer GroupInitial Brief:When the building was originally constructed, there was a natural smoke control system. However, due to very efficient insulation and a communal boiler, the building was becoming exceptionally warm, with corridors sitting between 40 and 50 degrees celsius.Sertus were called on to supply industry leading products, which would stop the heat build-up issues.Outcome:Sertus supplied, mechanical pods, roof single leaf vents and roof vent collars to this project. View these products here.

OverviewMechanical Smoke ventilation system designed and installed by Dyers Environmental Controls Ltd at Droylsden Marina.Project BackgroundThe Wharf, set alongside Droylsden Marina offers a collection of modern 1, 2 and 3 bedroom apartments which required a mechanical smoke ventilation system. Dyer Environmental Controls Ltd supplied and installed a mechanical smoke ventilation solution in a Watkin Jones Homes development. The fully automatic EN certified system allows safe escape for residents and clear access for firefighters.Project SolutionDyer Environmental Controls Ltd supplied and installed a mechanical smoke ventilation solution in a Watkin Jones Homes development. The apartment block has 6 levels connected by a central staircase. Dyers installed EN certified dampers to each floor along with local smoke detection. The fans were placed within the smoke shaft with a Powrmatic N-SHEV Roof Opensky louvred ventilator situated above them, providing weather protection. A control panel operates the duty and standby fans. Two AOV smoke dome vents are in place to provide smoke clearance, one located on level 6 and the other on the central staircase.Project ResultThe Powrmatic open sky louvre is situated above the smoke extract fans, providing weather protection. If smoke is detected in the building the system will open the corridor AOV, smoke shaft damper, head of stair vent and open sky louvre. The duty fan will run to extract any smoke located in the corridor. In the event of a power failure the standby fan will engage. Dyer’s fully automatic system allows safe escape for residents and clear access for firefighters.

Nakheel Mall, Dubai’s 435,000 sq.metre retail and lifestyle centre located in the unique Palm Jumeirah development, is using control solutions and 192 actuators from SE Controls as part of the fire safety and smoke control system at the new complex.

Electricity House, Crest Nicholson Homes’ stylish city centre apartment development in Bristol is using an advanced smoke ventilation system from leading smoke and natural ventilation specialist, SE Controls, to help keep residents safe if a fire should occur.

An integrated smoke control and environmental ventilation solution from SE Controls is helping keep residents safe and comfortable at a prestigious 11-storey residential development in Manchester, which also incorporates the company’s intelligent temperature monitoring and control system, SE Evello.

The £38 million conversion of the former Terry’s chocolate factory in York into ‘The Residence’, a development of 173 luxury apartments, is using a SHEVTEC smoke control system from SE Controls, to help keep residents safe in the event of a fire.

The new energy efficient Agrivaal building in Pretoria’s Tshwane Central Business District is using advanced natural ventilation and smoke control solutions from SE Controls Africa to maintain a comfortable indoor environment while improving safety by ensuring escape routes are smoke free in the event of a fire.

As the leading manufacturer of fire and smoke curtains, Coopers were appointed to develop a smoke curtain system to provide an unintrusive method capable of controlling smoke migrating from the lower floors. It was also necessary to protect the un-insulated glazing installed above the atrium’s reception area with an approved fire curtain barrier system approved to provide a one hour insulating zone. Coopers manufactured, installed and commissioned two SmokeStop smoke curtains developed to control smoke generated in the event of fire and effectively channel it away from occupants during evacuation.

Deansgate Square, one of Manchester’s highest profile city centre residential developments, is using mechanical smoke control and ventilation solutions from SE Controls to protect residents by keeping corridors, stairwells and escapes routes clear of smoke, should an apartment fire occur.

A combined smoke and natural ventilation system at a leading Western Cape wine grower’s new production facility at Simondium is using chain actuators, monitoring and control solutions from SE Controls Africa to help provide a comfortable and safe working environment.

A new prestige office development in Sandton, Johannesburg is using a combined smoke and natural ventilation system, involving automatic window vents in the building’s elliptical glazed central tower, which is actuated and controlled by an integrated solution from SE Controls Africa.

A new 1000 seat multi purpose entertainment and sports centre at Holy Rosary School in Johannesburg is using precision automatic window actuators and control systems from Durban based SE Controls Africa, to provide effective smoke ventilation in the event of a fire.

A new sixth form study and careers centre at Hampton School in South West London is using a combined ventilation and smoke clearance system from SE Controls to help provide a comfortable learning environment with enhanced fire safety for students and staff.

OverviewHead of stairwell High Rise Student Accommodation Ventilation designed and installed by ADS (Air Design Systems) at a brand new student accommodation on Friars Road, Coventry.Project BackgroundTrinity View is a brand-new student accommodation in Coventry with Six iconic blocks for 614 students, all set around a private courtyard which required a smoke ventilation system.Project SolutionADS (Air Design Systems)  installed Powrmatic N-SHEV Stirling natural and smoke ventilators at the head of three stairs along with Stirling vents above the smoke extract fans in two smoke shafts. Along side these smoke ventilators, a Powrmatic N-SHEV Wall Opensky was installed at the head of a separate smoke shaft that terminated in the Façade. The Stirling Casement Ventilators were operated by 24v drive open/drive close actuators opening to 90° and painted to a RAL 7016 colour to match the existing building. The Roof Opensky N-SHEV ventilator was also operated by an electric 24v drive open/drive close actuator with single skin aluminium blades mounted on a turndown base.Project ResultADS (Air Design Systems)  delivered an expectational high rise student accommodation smoke ventilation installation which was handed over on time and in budget with their customer. The student accommodation now benefits from a life safety smoke ventilation system. ADS also provided the smoke shaft dampers, the facade FLW Fieger louvred vents and the full control system for the accommodation. The 4 different sized Stirling Casement ventilators offered 1.04m² (x2) , 1.32m², and 1.15m² Free area to Approved Document B.

A combined smoke and natural ventilation system from SE Controls Africa is helping create a comfortable and safe environment for visitors at the Sci-Bono Discovery Centre in Johannesburg, South Africa.

Product:Surespan 140° thermally broken aluminium smoke ventilator and roof hatch designed to EN12101-2. ]The AOV also offers push-button comfort ventilation in one package! This one-stop solution for smoke vent requirements to meet building control can achieve 1m² airflow and is available in standard stocked sizes or made to any size in between 900 x 900 and 1260 x 1260. Wind deflectors to improve airflow. RE 1,000 Ventilation 10,000 Vent Offset mechanism for Roof Access Snow Load SL500 Wind Load WL1500 Temperature Class T (-15°) Fire Resistance B300

Atria natural smoke ventilation in accordance with EN 12101-2 for a mixed use premises. System design, product supply and partner installation of a natural smoke ventilation system including battery back up to ensure failsafe operation in the event of mains power failure.

SE Controls' brief was to supply, install and project manage a full turnkey solution to meet the fire safety and smoke ventilation needs in three of the new buildings at the Nottingham Chettles Yard student housing development.

A Wiltshire farmhouse has updated its heating system, replacing its original heat pump with a Grant Aerona³ air source heat pump which has been installed alongside a QR hot water cylinder. The new heat pump and cylinder were integrated alongside an existing solar thermal system, giving the property’s renewable heating system an upgrade.

Royal Winchester HouseComer Homes is renowned for the high quality of its residential and commercial developments, which span London, Hertfordshire, Dorset and throughout the South East. Its latest project is Royal Winchester House, a landmark building of one and two bedroom apartments at the heart of Bracknell's new town centre. As a planning requirement of Bracknell Forest Council, Comer Homes was required to provide a sustainable, low energy form of heating that would offer a reduced carbon footprint, as well as being affordable to run.The SolutionComer Homes specified F730 Exhaust Air Heat Pump systems from NIBE for all 337 apartments on the development to ensure they could meet their renewable targets. The new homes builder employed MKP Consultants Limited to undertake the building services design as they had previous experience of NIBE systems on other apartment developments in the area.The NIBE F730 Exhaust Air Heat Pump system was an ideal solution, as it offers mechanical extract ventilation, alongside heating and hot water in a compact design. The heat pump units were installed in a service cupboard in each apartment, as they have a small footprint of only 0.6m2.NIBE F730 operates by recovering energy from the ventilation air and, if desired, extracted from outdoor air, the heat energy is absorbed by the heat pump using a vapour compression process and subsequently transferred to the water-borne heating system, in this case an underfloor heating system. The integrated 180L domestic hot water cylinder also ensures a plentiful supply for the one- and two-bedroom properties.A sustainable solution, NIBE F730 keeps energy consumption to a minimum. The efficient control system automatically adjusts the indoor climate for maximum comfort for the occupant, using a combination of weather compensated control and the low energy inverter driven compressor.Each apartment is also fitted with a NIBE RMU 40 room controller, to allow greater flexibility of control for users and if required can be easily connected to NIBE’s internet remotely monitoring and control platform UPLINK™.Thanks to this innovative heat pump system, residents at Royal Winchester House are set to benefit from lower energy bills and a reduced carbon footprint.The ResultsThe NIBE F730 system complies with Parts L, F and G of the building regulations, and helps to meet planning requirements designed to reduce energy consumption and carbon footprints within residential housing developments. External noise is kept to a minimum and building aesthetics are unaffected by the need for external plant.TestimonialHead of Projects at Comer Homes, Jack O’Brien explains: “We were looking for a heating and ventilation system that would be both sustainable and affordable to run. We have been impressed with the performance of NIBE’s heat pumps, with their high efficiency, low noise and low running costs further enhancing the sustainability of the whole development.”About Royal Winchester HouseRoyal Winchester House is a landmark building of high specification 1 and 2 bedroom apartments available to rent. The unique design and architecture of Royal Winchester House creates a striking and impressive presence from the ground floor retail spaces up to the luxury penthouse levels.Royal Winchester House has been built for the private rental market and the development is being managed by Chancellors estate agency. The apartments benefit from high standards of insulation and air tightness. In addition to the NIBE heat pumps, the whole development has been fitted with a biodigester for the repurposing of food waste, as part of reducing waste sent to landfill and to add to its sustainability.

OverviewA sheltered housing accommodation owned by Bournemouth Borough Council were in need of a new smoke ventilation systemProject BackgroundSix blocks of sheltered housing accommodation owned by Bournemouth Borough Council were in need of a smoke ventilation system. The project was carried out to replace older ventilators that were proving unreliable and did not meet current requirements for energy performance.Project SolutionPowrmatic Krystalite louvres were selected from a shortlist following a tender exercise by Bournemouth Borough Council, and installed by Dorset Electrical and Fire Alarms (DEFA). They are located at the ends of corridors and stairwells, providing natural daylight and ventilation to common areas, with automatic smoke and heat ventilation in the event of a fire.Each ventilator is equipped with a manual switch for residents, as well as rain and wind sensors, to automatically close the louvres in bad weather. In addition, the warden has a manual override function to close the louvres at night, safeguarded by an anti-finger trap facility.Project ResultKrystalite ventilators feature high levels of thermal insulation, combined with a polyamide thermal break to minimise energy losses. Consequently, Bournemouth Borough Council will benefit from improved energy efficiency while ensuring the safety and comfort of its residents.

Salthaven Apartments, Tower Road, Poole, DorsetThe Salthaven apartments in Dorset aimed to deliver luxury living for occupants. Bayview Developments not only constructed beautiful homes for them, but also opted for highly energy efficient heating within the new development.Each of the 12 two or three bed apartments have been fitted with their own individual exhaust air heat pump (EAHP). This technology has been installed in buildings across continental Europe for many years but is now being used more commonly within the UK. Bayview Developments were looking to exceed their planning requirements by reducing carbon emissions and providing cost savings for occupants. NIBE’s innovative EAHPs were therefore the ideal solution.The solution to the projectA NIBE F730 EAHP system removed the need for gas boilers, something Bayview were keen to do given the UK’s net zero targets and commitment to phase out the technology. As heat pump technology is powered by electricity, no gas has been installed at the site.The NIBE F730 unit can be found in the utility room cupboard of each apartment and is comprised of a ventilation system, a hot water cylinder and a heat pump – a complete ‘all-in-one’ product. It works by drawing warm air from the kitchen and bathroom to feed the heat pump, which extracts the heat energy. The recovered energy from the ventilation system is used to drive the heat pump process, which heats the underfloor heating and provides water for the integrated 180litre hot water cylinder. The stale air from the ventilation system is then released outside, whilst fresh air from outdoors is introduced via wall inlets with cleanable filters. The efficient system minimises energy consumption by combing ventilation heat recovery with heat pump technology, that is perfect for well insulated new build properties such as these.The ResultsThe EAHP systems meet the average annual heat demand of 6019 kWh for each individual flat whilst also providing instant hot water. Occupants are able to schedule their heating to suit their timetable and energy tariffs, and therefore benefit from lower energy bills. The system performance factor (SPF) measures 3.33 – this means the system is very efficient as every kW of electricity used to run the unit produces approximately 3 kW of heat energy.NIBE utilised connected electricity meters in 3 apartments to remotely monitor the systems performance across a 12-month period. NIBE was thus able to see how the systems met energy demand consistently for residents, keeping them comfortable and warm throughout the year.Energy consumption data shown in Figure 1 visualises electricity consumption data from the monitored apartments throughout the year. This data also covers the provision of all heat pump controls and continuous mechanical ventilation.Figure 1: 2022 Energy Consumption data for monitored apartments.The all-in-one system has shown a noticeable reduction in energy bills for each apartment too, with all 3 monitored apartments experiencing both monthly and cumulative cost reductions in their energy bills as shown in Figures 2 and 3. This comes with the additional peace of mind that consumers will be kept cool in the summer months with ventilation with no increase in costs.Figure 2 and 3: Monthly and Cumulative Heating Bills for Apartment 11 with the NIBE F730 heat pump compared to a natural gas boiler.The occupants of Apartment 11 are saving on average £130 on their annual heating bills with the heat pump system in comparison to a natural gas boiler, even with the additional provision of mechanical ventilation. We expect that these savings will continue to increase as the Government seeks to rebalance green levies to decrease electricity prices.Sunstone Energy Ltd, the installer for this project, told us how easy the control system is to use for this heat pump, allowing for heating and hot water to be available at any time during the day. The building also benefits from insulation, underfloor heating, smart controls, double glazing, hot water cylinders and mechanical ventilation with heat recovery (MVHR).TestimonialVictoria and John are both residents of the Tower Road apartment complex and have been comfortably living with the exhaust air source heat pump system for a year. They added “We are delighted so far with the new heating system, and love that it has been providing us with heating and hot water throughout the year, keeping us warm in the cold winter months. The heat pump works just as well as our older systems and it is great to know that we’re also doing our bit for the environment in the process.”About the installerSunstone Energy Ltd takes responsibility for delivering complete renewable solutions appropriate to their client’s properties. Their expertise includes the installation of ground source and air source heat pumps, underfloor heating, solar panels, biomass boilers and MVHR.  

SE Controls smoke ventilation products have been used at two new prestige, sports and SUV car dealerships in Tokai, Cape Town.

From the Tower of London to The Royal Palaces, Coopers is trusted to install fire and smoke curtains barriers for some of the world’s most iconic heritage buildings. With this knowledge, appointed architects Arrol & Snell assigned Coopers to develop a system that would help protect the cathedral’s Undercroft and Treasury from smoke migration in the event of a fire. The smoke barrier system had to allow visitors to exit the Undercroft and Treasury safely, whilst preventing smoke from entering the main body of the cathedral, but any system had to be sympathetic to its unique and ancient architecture.

A Grant Aerona³ air source heat pump has been installed at a home in Wiltshire, replacing the biomass boiler that was previously heating the property. Working together with an underfloor heating system, the Aerona³ heat pump is operating efficiently to deliver warmth and comfort throughout the home.

Ninety UDF-50 REM Bilco Natural Smoke and Heat Ventilators (NSHEVs) were installed in a large scale accommodation development at the University of Hertfordshire. The development at the College Lane Campus comprises a mixture of individual bedrooms, twin rooms and studios. All of Bilco’s NSHEV products are manufactured to the highest possible standards, are CE Marked and meet Construction Products Regulation 305/2011. At 1500mm x 1620mm Bilco’s double leaf UDF-50 REM Smoke Vents offer a 1.5m2 clear vent area – making them ideal for dwellings of multiple occupancy such as halls of residence.