Acoustic trickle vent. Many types of vent offer 2500mm² of air space each, so typically smaller windows in small rooms require 1 vent and larger windows (e. Acoustic trickle vent

 
Many types of vent offer 2500mm² of air space each, so typically smaller windows in small rooms require 1 vent and larger windows (eAcoustic trickle vent  Product Range: Ask us about secondary glazing todayVent-Trex is a unique combined overhead extract fan and trickle ventilator for kitchens and bathrooms that fits within the aperture on top of the window frame

There are 3 files available to download including: Brochures and Images. Q. Rytons are the leaders in vents for all applications and their acoustic performance is second to none. 5. Typically, standard trickle vent covers offer around 30-35dB noise reduction, whereas an acoustically treated trickle vent cover may offer a 40-45dB reduction when installed perfectly. test – a standard Titon slot vent and a so-called ‘acoustic’ slot vent. uk5. Make £2023 in 2023. Humidity control to regulate supply of fresh air effectively throughout the day in response to changing indoor humidity levels. 595mm trickle vent available in white only. Units comprise of an aluminium outer frame joined to a seasoned hardwood timber surround. BV, BV - TV. VAT. Trickle facility to allow air ingress even when closed. Glazed-in window vents are activated with a single finger. 18,395. What was surprising was the result of testing the ‘acoustic’ slot vent, for which a 35dB reduction was claimed. 96, Prolific: to 31/8/23 £663. News: Titon Appoints New CFO. Trickle vents prevent airflow when closed, and when open they allow a small amount of air to circulate around the room. Designed to improve natural ventilation in the home, trickle vents have often proved unpopular with homeowners because they can spoil a window’s aesthetic appeal. 18. Glidevale ALDB Acoustic Trickle Ventilator 4500mm - White. Trickle vents ; Trickle vents. Durable, easy to fit and fully tested. The aesthetically pleasing and patented design helps to reduce the visibility of the trickle vent on a window. If you had a window with trickle vents, and you are replacing it, you need to replace like for like. AirLiner: Extends from. 5000mm² Equivalent Area Performance from the smallest vent at 410mm long High levels of background ventilation are required when applying System 1 of the Building Regulations in new dwellings; Intermittent Extract Ventilation and Background vents e. Aereco develops innovative ventilation solutions for residential and office buildings with a key concept: the modulation of airflow rates according to. A trickle vent such as might be used in association with commercial windows is formed from PVC tubing in two convoluted paths. Flush fit | White ABS Plastic | 430mm long x 20mm wide x 10mm deep (4,000 mm 2 free area). Performance required. Download. Location. Keep your trickle vents open. Google has come up with various options. Resources. Summary 1. This ensures the levels of total background ventilation stipulated in the Building Regulations are met, while the level of noise entering a property remains at a minimum. The airvent SM 1200 is a high performance surface mounted window vent that achieves a sound reduction of up to 43 db Dnt Rw in the closed position. Our trickle ventilator products are available for delivery as. Background Ventilation is a key product for a healthy living environment. Single. 63cm². Let us know how you want the parts delivered and we can arrange it! New in this edition are rendered CAD images to give a clear view of our products. You must agree that from a customer point of view that is a very large pill to swallow for what they are and. 8W/m 2 K for triple glazing Environmentally conscious design - from FSC-certified wood to 93 per cent recyclable window units Versatile ventilation - combine different opening functions, trickle vents and louvres or specify sensor controlled unitstest – a standard Titon slot vent and a so-called ‘acoustic’ slot vent. uk info@titon. If you already have pieces of egg crate pattern acoustic foam lying around, you can use them to plug your air vent. Lockable restrictor (160mm or 270mm) Click vent. Surface mounted noise reducing acoustic trickle vent. 894 The Crescent, Colchester CO4 9YQ United Kingdom. We are experts in the design, manufacture, specification and supply of residential ventilation systems. Glazpart is proud to launch a new range of Plastic injection moulded trickle ventilators to meet the needs of today s building designers, window fabricators and installers. Both window and wall vents are a popular. Airflow figures are available on request. It will end up oozing out and coming down the frames/glass. *Series 5 & 6 Requires controls kit – sold separately. Consealed 90⁰ hinges for windows and casement doors. They are controllable, to give the option of having them open or closed. To help you find the right products for your needs, all our ranges are. Compare that to our old trickle vent that was 23mm, that’s just over 90% thinner. Ventilation and Noise. Condensation reduction; If your home has a problem with. The acoustic attenuators come in three sizes; 25mm, 50mm and 75mm, which provide different dB reductions. Non-electric acoustic though wall vent, provides controlled background ventilation and noise attenuation up to 50dB Dn,e,w. 400mm long with 2 x 13 x 162. Acoustic lining reduces. Our aluminium vents (look for the reference VAL) have thermal seals to stop draughts when closed. 2) Are they straightforward to retrofit, ie do i just unscrew my existing vent, slide in the new one and screw in to place or is there more to it. One of the major benefits is that it can be installed in the same. New higher equivalent area confirmed by the BRE. Aquwall HY Products. The self-regulating non-return valve prevents annoying chilly draughts, while the window vent itself is also designed for improved acoustic comfort. co. Window Vents & Wall Ventilation. Browse 10 free BIM objects and Revit families that are ready to use on your projects. Trickle vents must be left in the ‘open’ position to provide ventilation; Bear in mind that with uncontrolled ventilation, moist air and odours are spread around the home, often condensing in, or on, the fabric of the building. Acoustic trickle vents I am in a new build house (4 years old) and I am looking to improve the soundporoofing to the front of the house. This product is equally suitable for domestic and non-domestic applications. View details. Glidevale ALDB Acoustic Trickle Ventilator 4500mm - White. The Static Vent-A-Matic models (except PB) come equipped with an integral stormaguard as standard, to help reduce draughts. 250-368mm L with air brick fitted. 50 a set, conform to Building. Features & Benefits. Habitable rooms and kitchens: 8,000mm2EA, Bathrooms: 4,000mm2EA. Flush Fit. Acoustic STC –TV250 Vent and Canopy – open 35dB – closed 49dB. 5 year old house has trickle vents on every window, which let in a huge amount of cold air even when closed. If your property is near a busy road, railway or airport, trickle vents can be designed with a high-performance acoustic option to reduce noise. acoustic result. The unit has three fixed trickle speeds of 6l/s, 7l/s or 8l/s and two fixed boost speeds of 13l/s. It can be fitted with an XC13 canopy or GS22 grille. . Adding an extra pane of glass with our triple glazing will only provide a small increase in sound insulation, if all three panes are of the same thickness. Colour. This includes windows and doors in newly built homes, windows and doors in newly built extensions, as well as all replacement windows and doors, regardless of. Take your pick from a wide choice of essential trickle vents, noise-reducing acoustic trickle vents and glazed-in louvre grilles, all available in a wide choice of sizes, specifications and colours, from leading brands RW Simon, Greenwood, Glazpart and Duco. 2500EA. Choice of slot size. Trimvent® Select Xtra S13 is a surface mounted plastic slot ventilator that fits over a 13mm slot in a window and provides an Equivalent Area (EA) of 2000mm2, 4400mm2 or 5000mm2. • Exceptional attenuation of external noise pollution (up to 56dB), ideal for built up areas effected by traffic, railways and general noise pollution • Sonair F+ ventilates and cleans the air • Independently tested by the BRE • Air cleaning and filtration • Low energy consumptionThe complete acoustic kit (EHT + 125 mm duct + acoustic foam + acoustic canopy) can attain an acoustic attenuation of 52 dB, which places it among the best products available on the market. Glidevale TVES4dB Acoustic Energy Saver Humidity Sensitive Trickle Vent – BIM Object Download. Finish (inner and outer). 16 years ago. The ventilator provides outstanding Dn,e,w 42dB (A) for areas with high external noise transmission, those likely in PPG4 categories B, C and D. Acoustic window ventilator top of page. The range was developed to meet increased regulation requirements for sound reduction, and the increased noise exposure resulting from the. As expected, the standard vent was not very successful in keeping out noise. Trickle vents are activated with a single finger and provides passive. £59. Resources. We also offer the acoustic window trickle vent range in a selection of anodised finishes. Window Ventilation. Suitable for external wall thicknesses of 140mm and above. THIS AREA IS CURRENTLY BEING UPDATED – PLEASE FEEL FREE TO DOWNLOAD BROCHURE FOR FULL INFORMATION>. Damp Weather Shutoff – dual control adjusts. Trickle vents are not required. A decentralised Mechanical Extract Ventilation (d-MEV) system is a low energy, continuous mechanical extract ventilation system designed to draw. As UK stockists, Window Ware are proud to stock a wide range of RW Simon trickle vents, including framevents, acoustic vents, TTF slimline, as well as their ever popular vent-a-matic circular window vent. Proposal It has been proposed to redevelop the former Maybloom Club site, Bostall Hill, London, SE2 0RA, toTrickle Vents allow you to have a small aperture in a window for a controlled amount of ventilation. RW Simon are one of Europe's leading suppliers of domestic air management systems. Glazpart is proud to launch a new range of plastic injection moulded trickle ventilators to meet the needs of today’s building designers, window fabricators and installers. The SF Xtra Sound Attenuator ventilator is part of Titon’s SF Xtra range – and is already being widely specified throughout the UK by housebuilders and developers. Background ventilation can be provided by trickle. £5. Acoustic Vents are the ideal solution where air must enter a room whilst reducing the sound leakage and ingress. New trickle vents are being launched to offer increased equivalent area air flow. It features a thermal foam seal, rod control operation and also comes with a 10 year guarantee. favorite_border. That’s an extra £300 for ‘flimsy, unsightly’ trickle vents. All new builds since the early 1990’s require passive ventilation and the easiest and simplest form of achieving this has been trickle vents in windows and doors. Titon is pleased to announce the promotion of Carolyn Isom to the Titon Holdings Board as Chief Financial Officer. Acoustic Trickle vents. WHITE 400mm Trickle vents from just £3. Summary 1. Stuff the Vent With Acoustic Foam. Enjoy fresh air indoors with window vents. Our window vents are subtly integrated into your façade — and their acoustic damping comes as a bonus. 4000EA. Bulk Save - View Offer. 07 Jan. The Acoustic Energy Saver Humidity Sensitive (TVES4dB) and the Acoustic Low Profile (TVALdB450 and (TVALdB800) reduce sound travelling through the vent, whilst allowing ventilation into the property. Trickle Vents are designed to provide fresh air ventilation for improved in-home air quality while the window remains closed and secure. RW Simon Ltd have launched a range of acoustic ventilators to assist clients in creating a satisfactory solution for all their acoustic requirements. By allowing a controlled amount of fresh air to enter the room, window vents help to reduce condensation, dampness, and mould growth. Existing homes. It features a thermal foam seal and can be supplied in bar length. Yeah, it might be the same mechanism as what they use for mufflers (in which you. Trickle ventilators provide ventilation to the room without the need to open the main window, reducing noise levels as a consequence. The new acoustic vent is designed to provide both fresh air and noise control in buildings when combined with VELFAC SOUND windows. Advice on Trickle Vents on New House UPVC Windows. Our Products. RW Simon Ltd has an extensive range of Trickle Vents ranging in all different sizes to help achieve the amount of free area or equivalent area required to naturally ventilate a building in order to conform to building regulations, our range includes both. Interested in fitting an acoustic vent but struggling to find anyone with aany experience of them. However all future homes will require continuous mechanical extract to circulate air and even CMEV. Modularity of acoustic sets provides fl exibility for installation and acoustic performance. Designed and developed in the UK, Yales SlotVent allows an appropriate amount of air to pass through the window, helping to remove stale air and reduce condensation and mould, as well as enabling people in cities or near busy roads to benefit from ventilation without having to open their windows. Spent ages reading about it and it seems that they make a huge difference in terms of noise. Acoustic STC – TV425 Vent and Canopy – open 33dB – closed 46dB. Additional tips to help cut noise emissions from your MEV or MVHR systemTrickle vents allow for a small amount of ventilation even when the window or door is closed. £11. We also offer the acoustic window trickle vent range in a selection of anodised finishes. 5 year old house has trickle vents on every window, which let in a huge amount of cold air even when closed. You can get acoustic trickle vents for windows which apparently stop sound much better than ordinary ones. The first [22], specifically addressing trickle vents, surveyed 116 sources and mentioned three experimental studies (two schools, one office). Restrictor with ventilation position. Zehnder ComfoAir Range. Recesses over a 16mm slot. These trickle vents are screwed to the frame and can be operated by simple finger control. Additionally, they help remove stale air from the property, which is very helpful if there are any odours lingering in your home. They are there for a reason taping them up will only cause issues elsewhere. sales@titon. The SF Xtra is a high performance, surface mounted aluminium slot ventilator. Explore our product database and get technical information on VELFAC product ranges - including open features, accessories. (54 products) An air vent is a space generally in a wall, which allows air to pass through and installing air vents helps to promote this air flow. Enquire now, call 01805 623721 Configurations and results. Single. 125 months. This is due to sound reduction levels being measured differently for trickle ventilators when compared to windows. FREE DELIVERY on. The ‘p’ (projection) dimension of each can vary depending on if it is open or closed. Available in 2 sizes: This vent 2500EA - 250mm (L) x 25mm (H) x 70mm (D) Internal/86mm (D) External. Removable cover pannel conceals Ventient trickle ventilation unit. Features a slim line design with two stage opening with the benefits of sound insulation. It can be locked in the minimum as well as maximum flow position. Continuous ventilation has many benefits and offers solution to many social housing issues - especially mould and condensation mould and condensation. In addition, acoustic vents can also help to improve the overall acoustic quality of a room by absorbing excess sound waves. The Acoustic Energy Saver Humidity Sensitive Trickle Ventilator (TVES4dB) is perfect for use in built up areas nearby busy roads and motorways. An alternative is to install acoustic trickle vents. Designed for a shutter style open and closing mechanism. RRP from £34. The Airvent SM Ultima is a quality, surface mounted ABS acoustic window vent providing 40db sound reduction. Product Description. g in bedrooms, or living rooms, require 2 vents). This is more representative of a design in the UK that relies on trickle vents for a natural ventilation solution. 0800 970 4190. The RW Simon Ltd Framevent HF (hi-flow) achieves 4,191mm2 EA on a length of only 415mm & the HF + (hi-flow +) achieves 5205mm2 EA on a length of 525mm. Background - usually provided by trickle vents installed within a window frame ; Purge - either natural (by opening a door or window) or mechanical . Acoustic laminated glass; Sash Horns. Hopefully the first of many more upgrades, and after seeing Thermally Broken suites specified for over 2 years, good to see the requirements finally stick on a…Secondary glazing does not need trickle vents which improves the acoustic performance. The purpose of trickle ventilators is providing a consistent flow of fresh air. Acoustically damped pipe fitted around unit to reduce external sources of noise such as traffic. Suitable for bedrooms and other rooms where low. VAT. All buildings have to be ventilated in order to maintain the health and well being of everyone using them. Replacement windows should be fitted with trickle vents regardless of whether the windows being replaced had vents in them or not, if no background ventilation alternative is being installed. com / 01206 713801 Product Product Code (L) Length (W) Width (P) Projection Closed-Open Free Area (mm2) Slot Detail SF Xtra 2500EA Vent only TA5220 425 23 10-24 4207 SF 418 Canopy only TA5005 418 23 27 5114 SF Xtra Sound Attenuator 2500EA Vent 25mm TA5221 464 35 37-51 3470Our elegantly crafted trickle vents for casement windows come in a range of sizes, styles and colour options meaning there is something to suit every form of window. Rytons Acoustic Vents. This also allows them to be compliant with the latest building regulation requirements. Qty BPD Store. Schüco VentoLife is suitable for residential and office buildings and can be integrated not only in the Schüco AWS 50 to AWS 75 SI+ series including AWS BS. Trickle Vents are designed to provide fresh air ventilation for improved in-home air quality while the window remains closed and secure. Lockable restrictor (160mm or 270mm) VELFAC maxi-handle. V. Acoustic block ventilators are large, aesthetically unattractive and often cannot be accommodated. Features a slim line design with two stage opening with the benefits of sound insulation. This Video Is A HOW TO Guide on Fitting A Chlo Products Trickle Vent to A Window. People feel the draught and close the vent or think the room loses its heat. SlimVent has been designed with. Your Price Apply / Login. Learn More . Click here >. 894 The Crescent, Colchester CO4 9YQ United Kingdom. W. 4 mm in the Classic range. Cowled Super Acoustic Controllable LookRyt® AirCore® (Up to 50 dB Dn,e,w) Controllable air vent for background room ventilation. Finish (inner and outer). The room must achieve an internal noise level of 35 dB(A) over the duration of the measurement period. co. Add to Wishlist. Recently organised window fittings at a relatives house. The benefits of a higher performing acoustic ventLearn more: ht. com TV Select S13 & TV Select Xtra XS13/XS16/XR16 Plastic slot ventilators Ò Suitable for PVCu, timber or aluminium. Acoustic trickle vent. Visit our website now. Improved Db reduces noise to new levels of performance, especially in the closed position. W. blackthornjohn • 6 mo. Qty Glidevale ALDB Acoustic Trickle Ventilator 8000mm Add to Basket. About this product. Browse 11 products that are ready to use on your projects. Please click through our full range of window ventilation below for more information. VAT. 2500mm2 EA and 5000mm2 EA versions available. 79. Provides an outstanding Dn,e,w; 42dB (A) for areas with high external noise transmission. Triton brand aluminium trickle vents give you a small amount of ventilation via the window frame or a door frame as controllable or permanent version to reduce condensation in the room and freshen the air with natural ventilation. [email protected] and specify trickle vents from top manufacturers with NBS Source. We sell trickle vents at a price of £15 per vent (inc VAT 15%). Keep your trickle vents open. Nineteen different Trickle Vents are reviewed from some of the performance aspects in this paper. Most importantly, it influences the health of those who live and work in the building. This is particularly important in areas where this is more likely to happen, including. 6300mm². New building regs for future homes 2025 in new builds will not have them, further more they will be trippled glazed. Trickle ventilators provide ventilation to the room without the need to open the main window, reducing noise levels as a consequence. Air Brick: Terracotta, buff/sand, white, grey, blue/black, black, brown. 98, Interest: Jan-Aug £66. VAT. 99. An acoustic version is also available, developed to satisfy the ever increasing demands for noise reduction whilst providing the desired ventilation levels. If the windows are modern double glazing with trickle vents, it may be beneficial to replace the vent covers with acoustic trickle vent covers. There are many variables to consider in acoustic testing, please contact us for specific test figures on our range of trickle. Wasn't sure where to post this ! We moved into a new house in June2010, when it started getting colder we closed the trickle vents on all the windows but still have a draught coming through them. 2060 (1) 2200 (1) 2500 (2) 4000 (2) 4300 (1)Trickle Vents by Greenwood are available in various styles & Sizes Starting from 4. A trickle vent is also included. 1000 Pa. VAT. hello@brookvent. Technical Service: 01276 408402. So if the ventilator is effectively blocking sound in some way then the vent will let a lot less noise in than the window does when opened just a mm or two. Ironically, the spare bedroom (which faces a railway line) has acoustic vents through the wall rather than trickle vents through the window frames and it is. For 45 years, Titon says its core product has been the window trickle (or ‘background’) ventilator, claiming to be the biggest manufacturer and supplier of these products in the UK. These pared-down pieces of kit (measuring between 412mm and 250mm) are the smallest acoustic window vents on the market, yet they offer unbeatable noise-reduction (up to 45dB) and impressive. Many types of vent offer 2500mm² of air space each, so typically smaller windows in small rooms require 1 vent and larger windows (e. Enables secure, weather resistant ventilation with exclusion of insects. Glidevale Fresh 90dB Acoustic Wall Vent – BIM Object Download. White. The SM ULTIMA is a high quality, ABS acoustic window vent offering 2600mm2 EA airflow and providing a 40 db Dne W sound reduction in the. The Invisivent ® Air and Comfort window vents by Renson ® are controlled by the smart Healthbox 3. With its built in updraught and various operating modes the TTF Slimline is suitable for all types of windows. Acoustic trickle vent. Requirements . We offer a next day delivery timeframe, please be aware this is our aim and not a guarantee. As one of the market leaders in tile ventilator manufacture in the UK, Glidevale Protect’s range has been collated for over 35 years and includes hundreds of dedicated profiled tile ventilators matching almost. bulk or standard packed (as sets or separate internal ventilators & external grills) mix and match colours. Excellent acoustic control was a priority, as the site is surrounded by transport routes, including a railway line. Made of aluminium with ABS end caps. BPD Store stocks Passivent’s range of window tricklevents. Greenwood 5000EAW. 250-368mm L with air brick fitted. Glidevale Protect TVES4dB Acoustic Energy Saver Humidity Sensitive Trickle Vent - Trickle Vent . 99. The vents have an effective free area, in terms of how much air flows through, of around 4000 sq mm. As ventilation specialists, we are also proud to supply. Glazed-in window vents are specifically designed to fit along the top of the sealed glass unit, between it and the frame, by reducing the glass height. Ultra Vent and Grille. W x H x D: 258 x 240 x 8mm. RRP from £34. VIEW PROJECTS. stabilised. Condensation ventilation is available in a variety of sizes for new build and refurbishment and Rytons acoustic background vents for walls have BRE measured equivalent areas and acoustic (Dn. Additional tips to help cut noise emissions from your MEV or MVHR system Discover how acoustic ventilation can improve indoor air quality and reduce noise pollution with Greenwood, the leading air ventilation system manufacturers in the UK. Donald BSc (Hons) AMIOA T: 0330 043 1764 Page 4 of 24 1. Concealed and surface-mounted. Enjoy fresh air indoors with window vents. View. Trickle vents are activated with a single finger and provides passive. Special paint finishes available for trickle vents; Based on successful Trimvent® principle; Deflects air up and down; Thermally insulated; Matching screw covers;. Explore our product database and get technical information on VELFAC product ranges - including open features, accessories. Supplied with a removable protective cover. Single/Multipack. 4. 9 Feb 2017. All Glidevale Trickle Ventilators have been tested to meet the building regulations. Size: 400mm (L) x 20mm (H) x 22mm (D) Achieves sound reduction of 40dB closed and 33dB open. Tel:. Zehnder Group UK. Table 3. Hit & Miss: 271mm L x 95mm H. Smallest acoustic window vents on the market. Customer Service: 01276 408404. This SlimVent and Canopy set from Yale is a part of our comprehensive range of trickle vents that enables window and door manufacturers to meet the requirements of the latest revisions to Building. Buy As Trade Add to Basket. The ‘p’ (projection) dimension of each can vary depending on if it is open or closed. One of the best performing acoustic vents available in the UK. . Explore our product database and get technical information on VELFAC product ranges - including open features, accessories. Surface mounted noise reducing acoustic trickle vent. Can be removed to allow access to and maintenance of device. Do you need acoustic ventilators for your windows? Check out the Simon Acoustic Range, a comprehensive catalogue of products that offer high performance, durability. They are opened and closed manually. Ventilation systems. Internal Trickle Vent made from high quality 0. Happy trickle vent day! As of today, June 15th 2022, the newly revised Building Regulations for England have come into force. The ventilator provides outstanding Dn,e,w 42dB (A) for areas with high external noise transmission, those likely in PPG4 categories B, C and D. VAT. Recently organised window fittings at a relatives house. The acoustic trickle vent achieves a sound reduction value without compromising internal ventilation. Glidevale ALDB Acoustic Trickle Ventilator 4500mm Add to Basket. These vents are designed to help prevent or minimise problems associated with poor ventilation, such as condensation. Trimvent® Select Xtra S13 FOR USE ON PVCU, TIMBER OR. The Trickle Vent brings you the Sonovent Acoustic Solution which was developed to meet the two aspects of living comfort: Physical Comfort – fresh and healthy air without draught; Acoustic Comfort – up to 56 dB noise reduction; There are also four types (S/M/L/XL) with four possible air gasps (10,15,20 or 25 mm). Our largest vent, the TVALdB800, is capable of sound reduction up to 42dB Dn,e,w. Achieving stringent standards set out in Part L means high building fabric standards resulting in a significant reduction in heat loss and fewer gaps for air to escape. These new rules feature in Approved Document F, which provides guidance on adequate ventilation in properties, and will impact both new and existing homes, along with extensions and self. From manufacturing the first dMEV classified product in the UK in 2007 to our latest release aligned to the 2021 UK Building Regulations, our approach has always been set on delivering a low-energy performance product which. W. 9 millimetre material. Well, unless you have things in place to 'block' it, you will probably find that as it expands it won't just stay in the trickle vent. VAT. Restrictor with ventilation position. The. They deliver a constant airflow without having to actually open the. Helps to prevent mould and mildew. TV2000 Internal Trickle Ventilator:. Cost effective sound attenuating (acoustic) trickle ventilator. Discover how acoustic ventilation can improve indoor air quality and reduce noise pollution with Greenwood, the leading air ventilation system manufacturers in the UK.