Transfer Grille. Quick Links. GRILLES AND REGISTERS F DOOR/TRANSFER GRILLES PERFORMANCE DATA: DOOR/TRANSFER GRILLES – 5100 AND 6100 SERIES MODELS: 51DG, 61DG Listed Duct Size (inches) Alternate Sizes (inches) Core Area (sq. to return. Volume flow rate range 2 – 850 l/s or 7 – 3060 m³/h. Volume dampers or other means of supply air adjustment shall be provided in the branch ducts or at each individual duct register, grille or diffuser. Carnes also offers a line of Door/Transfer Grilles to allow airflow from one area to the next while maintaining privacy with Light Tight construction. A collection of intumescent air transfer grilles offering protection against fire. These fire resistant air transfer grilles are developed to allow the free circulation of air at room temperature through construction elements (walls, doors etc. Blades are chevron in configreation and are mounted in a fixed position ina rigid PVC track in an integral part of the frame. Registered in England and Wales: 673483. wait: 1 min. And with an experienced team of Sales. 001. Use with 44mm Liner for FD30 doors & 54mm Liner for FD60 doors. However, the door creates a pretty tight seal so I'm wondering if there's enough airflow to do so without overworking the dryer. Pyrogrille air transfer grille allows free air flow and provides up to 60 minutes fire protection. James Gilbert & Son specialises in high quality decorative metalwork. 452 likes. View Products. Innovative. 4. Series L Linear Bar Grilles. The ATG/BF comes complete with mounting flange plus a loose telescopic rear flange to suit a minimum thickness of 42mm up to a maximum thickness of 110mm door or partition. 359. 603. Model includes a v-shaped louver providing a sightproof return or exhaust grille regardless of the viewing angle. £7. ft. ) Nominal Size Core Velocity (fpm) 100 150 200 250 300 350 400 Velocity Pressure (in. Bespoke designs, priority order and guaranteed delivery dates. NV4: Slimline surface mounted with a non-chevron blade, designed to suit fire doors. Gilberts Non-Vision Louvred Grille | Air Transfer Grille Cover. Series FB Air Transfer Grille. James Gilbert & Son specialises in high quality decorative metalwork. Original plan was to take my central air return in the hallway and stub ducts in the attic to get individual air returns to each bedroom. PERFORMANCE DATA STG Core Area (sq. 3 (7) Download. The Perfect Balance In-Door Return Air Pathway is a Durable ABS plastic grille with a noise and light dampening baffle that is installed into the bottom of interior doors. TYPE GPS4 & GPP4 -Air supply or extract grille fascia for applications using a seperate plenum box. 40 + VAT. We can supply vents in a bespoke design to suit your requirements. Nominal sizes 225 × 125 – 1225 × 525 mm. Day-to-day this enables efficient ventilation but during a fire will seal shut, stopping the fire spreading further. Engera Bathroom Door Air Vent Grille Two Sided Ventilation Cover for Restroom, Warehouse, Storage Doors | Interior Door Transfer Grill 453mm x 91mm (18. Acoustic vent grille to allow ventilation whilst reducing sound transfer from room to room. Single Core with Flat Frame. Excellent for installation in doors or partitions. Uniclass Code : Pr_70_65_04_03. when doors are closed. Suitable for use in doors, Modern Slavery Policy. Air 360 Vent Cover Return Air Grille – 22 x 22 Inch Transfer Grille AC Vent Cover – Durable Rustproof Aluminum Design – Optimal Air Flow – Low Noise Wall Vent for Residential, Industrial Use. A. The aluminium ‘V’ shape chevron blade mounted on a close Grilles View Products Diffusers View Products Domestic View Products Supply & Extract Valves View Products Finish Options View Data Sheet Download. Designed for installation into fire resisting doors, walls and ducts. 98 -9%. ALN, ALM, ALF, ALG, ALJ Airline Linear Grilles 14 APF, APG, APJ, APN, APM Plasterline Linear Grilles 16 UC / UF / UE Urban Grilles 17 Door / Sidewall Grilles NS, DV, NSNL Air Transfer Grilles 18 DSR, DSRX Acoustic Air Transfer Grilles 19 T P W Ss e l l i r G l l a w e d i 20 WFV, WFVG Fire Rated Air Transfer Grilles 21 Floor GrillesWaterloo transfer Grilles are suitable for mounting in doors, partitions and Walls to allow ventilation air to pass between adjacent rooms. 001. uk. 006 0. com 0344 856 0594. Door grilles provide visual security and limits light while allowing air transfer through doors or walls. Wrapping up smoke and fire protection with our range of Fire Dampers, Smoke Dampers, Smoke/ Fire Dampers, Intumescent Air Transfer Grilles and Air Volume Control Dampers all developed to the latest test standards. Their special features make them ideal for placing in doorways and interior walls. 002. These grilles also have a 6mm vermin proof mesh fitted to both faces, so unwelcome. when doors are open. w. Grille face made of aluminium with anodised finish 30 mm wide front border Countersunk holes Optional equipment and accessories Grille face in RAL CLASSIC colours Installation subframe Matching rear frame for door installation. QuietCool Zone Air Pathway Kit 14" x 08". ) Nominal Size Core Velocity (fpm) 100 150 200 250 300 350 400 Velocity Pressure (in. The Perfect Balance In-Door Return Air Pathway is a Durable ABS plastic grille with a noise and light dampening baffle that is installed into the bottom of interior doors. Manufacturer : Madel. The Perfect Balance is typically installed in a bathroom or mechanical room door for the purpose of providing make up air for the exhaust fan. Description. Nominal sizes 150 × 105 – 1500 × 985 mm. Gilberts has built a reputation for providing an extensive range of contemporary, value engineered products at the best in competitive. Type NV6 Vision proof flanged grille suitable for surface mounting onto doors, wall or partitions. or use our online contact form. Normally, when there is ducted returns, the filter is located at the air handler. If you’re in the process of soundproofing a room, you might be in a little pickle if you have to deal with an above door air pathway transfer grill, most com. The above-door transfer grille simply has two grilles located above the door between the room and common space, one on each wall, with offset baffles to limit sound transmission. TransShield ACS is a slimline non-vision intumescent fire and smoke damper with a unique sliding plate smoke control system. 2. SG-SD. If the doors are going to be closed, then returns are needed. Especially useful for narrow doors or fireblock installations. 1 (7 reviews) Extruded aluminum grille supply. Established in 1972 in the family garage, HVC Supplies has developed steadily over more than 45 years to become the industry leading company it is today. We are committed to clarity in pricing which is unambiguous although this Site does not contain any pricing information. Series FB. Maybe you can have transfer grilles installed to those rooms verse ducted returns. In the event of an alarm condition, or power failure, the smoke shutters shut, preventing the passage of cold smoke. Series XG-DG extruded aluminum door grilles are designed to transfer air through doors or walls. 002 0. Floor diffusers. Download Now. In line with the smaller Louvres this series offers a high resistance to weather ingress combined with a good 50% free and both flanged and recessed channel frame options can be selected along with standard bird guard and insect screen accessories. 55 KB: Preview: waterloo-air-products-plc_ns-non-vision-transfer-grilles_photo_3_d32b8ba8-bdc8. TYPE GPS3 & GPP3 -Air transfer grille arrangement comprising of a high security bolt fixing unit on one side and a lower security clutch screw unit on the other. Du ctodamp esl v ni 7. Modern Slavery Policy. It is designed for air transfer applications through fire rated doors and walls. Transfer grilles shall use 50 square inches (of grille area) to 100 cfm. TROX Services. 001. The grill will be larger than you think, at least 18" square. Displacement diffusers. Mm Craft Mill Finish Designer Ss Door Grill, For Home ₹ 1,050/ Square Feet. We are the world's oldest manufacturer of decorative metal grilles. (Matt black finish). It may be surprising that just these three systems — mechanical, electrical and plumbing (MEP) — can make up as much as 15% of the total environmental footprint of a building's. Introduction Gilberts FB Series provides a compact, efficient range of intumescent fire dampers designed to satisfy all types of air transfer application in offices, shops, schools, hospitals and many other commercial projects. Company. ft. Normally, with a single RA grille that'll be where the filter is. : Bedrooms with a design supply airflow ≥ 150 CFM are specified with any combination of transfer grilles, jump ducts, dedicated return ducts, and/or undercut doors to achieve a Rater-measured pressure differential ≥ - 5 Pa and ≤ +5 Pa with respect to the main body of the dwelling unit when all air handlers are operating. 0006 0. Because transfer grilles connect two rooms or a room and a hallway, there is nothing that is blocking sound between the two areas. This is partly due to a privacy issue. Aluminum Construction. Performance cannot be guaranteed where alternative plenum designs are used. Introduction Gilberts NV Series provides a comprehensive and traditional range of vision proof grilles to suit all manner and type of air transfer application through doors, walls and partitions. With a class leading range that includes a mix of both leading edge & traditional designs, as well as standard or bespoke, we have the product to suit your project and your budget. Is it ever OK to install a transfer grille? Sure. AGS-T read more. Our range of Non-Vision Grilles models include: NV1: Standard flanged grille. Electrical conductor hinges are used for the concealed transfer of power from fire & smoke air transfer grilles into the door leaf. NV2 is a Vision proof core in 32mm flanged border. Product, Technical. 450x92. This gives good room ventilation as a result of mixed ventilation. Gilberts Garage Doors. . DESCRIPTION: Construction: Frame and blades are 6063 extruded aluminum alloy with 200-R1 satin anodized finish. Door controls. Aluminum door grilles. press machinery and production techniques the FB700 is<br />. ) 0. 4 Return Air Grille ARG 19 1. Duct registers, grilles and diffusers shall be installed in accordance with the manufacturer’s instructions. Our range of combined intumescent fire + smoke air transfer grilles can be used in all applications where cold smoke containment is required. In many cases, pipes and ducts. +27 (0)33 398 1006 Fax. - Individually Adjustable Aerofoil Blades. 010Waterloo transfer Grilles are suitable for mounting in doors, partitions and Walls to allow ventilation air to pass between adjacent rooms. These are particularly suitable for doors to staircases etc. Single Louver Grilles: Titus’ 300/350 Series supply grilles define the standard for the industry. Air Velocity : 75 m/s. In line with the smaller Louvres this series offers a high resistance to weather ingress combined with a good 50% free and both flanged and recessed channel frame options can be selected along with standard bird guard and insect screen accessories. with a door sleeve and electrical door wiring loop for a 45mm or 54mm door or a wall sleeve only, for a wall/partition. Favorite. com Web: SERIES HG Sport & Gymnasium Grille Ordering Specification QUANTITY SERIES: HG SIZE (mm LENGTH X HEIGHT) FINISH 2 HG. TRH-A series grilles have a simple design which makes them useful for incorporation in all styles of architecture. Canadian iron main entrance doors gate grill design single door $35. uk . Construction is from all aluminium extrusion with fixed full chevron blades. Air Flow : 21 m3/h. 02576. For Enquiries contact us on +44 (0)1384 376555; Recently viewed items ;The Halton TVC transfer grille can also be used together with an opposite frame accessory (OF) to complete transfer unit for 25 to 50 mm thick doors or partition walls. DESCRIPTION: Construction: Frame and blades are 6063 extruded aluminum alloy with 200-R1 satin anodized finish. LVH20S intumescent fire + smokeAcoustic Transfer Grilles DSR Acoustic transfer grille DSRX Acoustic transfer grille for variable depth DSR2 Back to back acoustic transfer grille. Acoustic Transfer Grilles DSR Acoustic transfer grille DSRX Acoustic transfer grille for variable depth DSR2 Back to back acoustic transfer grille. The. Series FB Air Transfer Grille. PERFORMANCE DATA STG Core Area (sq. In this case, their height will be determined by your system. The LVN25 is a non-vision intumescent air transfer grille. Gilberts Blackpool. grilles, ducts Brackets: remove, box in or chase into wall Grilles: perforations should be a maximum of 3mm in diameter. Our grilles have high quality paint finishes and accessories to suit your individual requirements. 2. w. WFV, WFVG, WFG Fire-rated Air Transfer Grilles. 175m3/sGilberts’ NV/6 non vision transfer grilles are surface mounted into doors and blockwork, allowing the passage of air and light whilst obscuring vision, whilst the Smokeguard dampers allow ventilation view a drive mechanism that enables airflow in normal circumstances, closing to prevent smoke and flame penetration in the event of a fire. With a dedicated design team working on both new developments and. With this new Series Gilberts provide a comprehensive range of stainless steel grilles and diffusers designed to suit the most demanding of projects. Intumescent air transfer grilles to satisfy air transfer application in doors or walls. In a fire, our intumescent air transfer grilles expand to form a solid block that stops fire spreading. . NV2 Grille. Any guidance the committee could provide in this area would be most helpful. <br><br>The Perfect Balance In-Door Return Air Pathway is designed to maintain adequate air flow between rooms and eliminate pressure imbalancesallowing each room. This may cause the damper to scream. Even more important is the operation of these systems, particularly mechanical and plumbing. ITEM # MODEL SIZE (") 720541 350RL 20 × 18 720542 350RL 20 × 20 720544350RL 22 × 22 720545 350RL 24 × 6 720546 350RL 24 × 8 720548350RL 24 × 10 720557 350RL 24. Cut the wallboard using your drywall saw and set the metal frame in place. 2 Slimline Wall Grille ASG 11 1. General. Share. Speci˚ed Door Opening Speci˚ed Door Opening - 1/8 1 5 16 2 13 32 Model : XG-DGCO ( Door / Transfer Grille - Core Only ) Model : XG-DGSF ( Door / Transfer Grille - Single Flange Frame ) Model : XG-DGDF ( Door / Transfer Grille - Double Flange Frame ) Model : XG-DGLP ( Door / Transfer Grille - Light Resistant ) Face View ( Models: XG-DGDF &Lorient has been developing high quality intumescent air transfer grilles for over 40 years; combining air movement with fire protection & making buildings s. Designed for. Transfer Grille Baffle. Door/Transfer Grilles. 4. 021 250. Aluminum Transfer Grille (ATG) Overview. 033 300. 6" Inch Door Air Vent Grille Two Sided Ventilation Cover - White - Overflow Ventilation Grill - Door Vent Cover - Free AIR Flow Between Rooms -. December 19, 2020 ·. Carpets will filter the air and remove all the candle soot and other airborne particulate, as it is forced under the bedroom door due to a high pressure difference. The LVH20S damper is a unique combination of intumescent slats to provide two hour fire resistance + excellent insulation properties together with a servo powered set of shutter plates that control cold + warm smoke. Model includes a v-shaped louver providing a sightproof return or exhaust grille regardless of the viewing angle. In the event of an alarm condition, or power failure, the smoke shutters shut, preventing the passage of cold smoke. Horizontal and vertical moving slats for an individual regulation as they adapt the air range and the air stream to the needs of the zone. DSR units will only provide acoustic isolation improvements over that of a clear aperture. Available Options 4. A range. Vision proof. Total No of Grilles = 10m3/s = 28. Domestic Warm Air Heating Grilles. METALAIRE is the flagship brand of Metal Industries Inc. Over the last 135 years we've produced architectural quality metal works for some of the biggest brands on the planet, yet we don't forget our. We supply a range of Stainless Steel ventilation grilles, trickle vents, hit and miss vents. Fisher & Paykel 36" Grill with Infrared Sear Burner, LP Gas. Featuring all-welded construction and integral wall sleeves. Aluminum Transfer Grille (ATG) Overview. 9% and improve hygiene. NV3 is a Vision proof core in 32mm flanged border with matching telescopic back flange. Submit a request online and get a quote from your local representative within 4 hours. 005 150. Floor diffusers. Take a flow hood and check cfm with the door open and the door closed, with a 1" undercut on a bedroom door you will have a serious cfm drop. 4. Door/Transfer Grilles. Louvred Grilles designed to satisfy all types of air transfer<br />. Gilberts NV Series provides a comprehensive and traditional range of vision proof grilles to suit all manner and type of air transfer application through doors, walls and partitions. Introduction. ) 0. 1. Name. Please note the existing silver finish will now be supplied in a new industry-standard satin silver finish of RAL 9006. It adjusts to suit a door thickness from 1-3/8" to 1-7/8". Blades are chevron in configreation and are mounted in a fixed position ina rigid PVC track in an integral part of the frame. If at hallways, then, they are a code violation nowadays, as door grilles are not fire rated, there may some rated doors with grilles, but it is your case? 2. Send us a messageFire and Smoke Resistant Dampers / Air Transfer Grilles System Benefits 3 Product Range 4 - 5 Operation 6 Lorient Smoke Control Systems 6 - 8 Product Solutions 9 - 18 - Doors 13 - 14. Showing 11 of 122 products. An electromechanically operated shutter smoke mechanism closes its slats in the event of a fire alarm going off, thus stopping cold smoke and flames from passing. 40 + VAT. 6171Revision: Date: Units: Page: Model: ® OF Submittal: XG-DGDFSS Stainless Door Grilles Door. Get Quote. Minimum Unit Size is 6”x4” with a Maximum. +27 (0)33 398 1100. Drop one in one side then go on the other wall behind and drop the other in. Line the aperture with a 6mm hardwood liner. 5 Egg Crate Grille (13Mm) AEC 23 1. With any distribution system, there must be a return path for the energy distributing fluid. CT-700L. We are the world's oldest manufacturer of decorative metal grilles. It's a return grille, most likely. We can accommodate bespoke sizes or larger quantities – please get in touch with our team on 02920 857. Available in nominal 2" (51) increments. . GILBERTS DAMPERS 8 MAY 2005 PUBLICATION Features 60 or 120 Minute Fire Rating. Available in either steel or aluminum construction with either single or double flange frame options. Many have duct work in crawlspaces, so the registers are placed in the floor. co. Intumescent air transfer grilles to satisfy air transfer application in doors. EI rating of 120 minutes when used. The Waterloo fire rated ventilators are suitable for 1 hour rated doors and partitions. Acoustic, smoke + fire containment systems. They can be used for providing dampers in ductwork. 30 mm wide front border. Transfer ducts may achieve this by increasing the return transfer 1 1 / 2 times the cross sectional area (square inches) of the supply duct entering the room or space it is serving and the door having at least an unrestricted 1-inch undercut to achieve proper return air balance. When posting in certain forums, knowing your location will. 048 350. 7mm Mild Steel Construction. 001 0. Visit the Quietcool Store. Lorient Code of Conduct. LOUVRES. AG50 Bar Grille. 8 m 2), the closet door shall be undercut a minimum of 1. ) 5. Designed for door transfer in dark room/light proof applications. 1"x3. The grille vanes are individually adjustable to allow jet spread or deflection to be set within 45 of the duct axis. Blades are chevron in configreation and are mounted in a fixed position ina rigid PVC track in an integral part of the frame. 004 0. Also, if the crawlspace access door is left open, it may not be discovered for some time. Their special features make them ideal for placing in doorways and interior walls. 30 mm wide front border. Jackshaft (indicates damper positioning) 9. It adjusts to suit a door thickness from 1-3/8" to 1-7/8". Door / Transfer Grilles Products Matching Your Selection METALAIRE is the flagship brand of Metal Industries Inc. Series SK Heavy Duty. Supply and extract grilles for all building types including double and single deflection grilles, egg crate cores, security grilles and data centre floor grilles. Polyaire Product Catalogue - Door Relief Grille. The Gilberts non-vision stainless steel louvred grille is suitable for surface mounting in both door and wall applications and is ideal for both standard air transfer and fire rated applications where intumescent type fire dampers are utilised. Return/Exhaust/Transfer Air. A chef inspired food truck, centred around humanly raised meats that are cured and processed in “hAir Transfer Grille Introduction Gilberts FB700 Series presents a range of Mild Steel Louvred Grilles designed to satisfy all types of air transfer application in offices, shops,. Published by Raúl Galdrán from BIMETRICAL on 1/8/2018. Air transfer grilles are vents that are fitted into doors or walls to allow air to move freely around a building, helping it to stay ventilated. For both fire and smoke protection, see the Lorient LVN20S Air Transfer Grille. Working from a purpose designed production and warehousing facility in the West Midlands, we are capable of producing everything from the. “While undercutting doors can create part of the return air path, wall transfer grilles or jump ducts should be installed to prevent the return problems,” the Building Science Corporation warns. A definitive guide to operating theatre diffuser selection in accordance with HTM-03-01. Integrated flow regulation damper. Steel Maximum Security Suicide Deterrent Grille. 004. Skip to contentThe IFD-D intumescent door grille kit is suitable for new or existing Proprietary fire resistant doorsets that may require air transfer or pressure relief. HVC Supplies also offers one of the. Product 150 Intumescent Ventilation Grilles (SVG & HMG)blades. For installation information not covered in this sheet, refer-ence appropriate damper basic installation instructions. Supplied in two pieces it lends itself to easy installation in a standard 44mm thick fire door, + when finished with a colour co-ordinated edge flange, results in an attractive but efficient air transfer feature. Inverted V type grille bar for best vision proof quality and airflow. LVH20S intumescent fire + smokeThe Ligature Resistant Retrofit Exhaust/Supply Grille is designed to replace existing grilles that are not ligature resistant. ) Ak Factor Core Velocity Pressure Neg. 3. 71 inchesTransfer Grilles should not be fitted on doors which are required for smoke sealing compliance. Domestic Warm Air Heating Grilles. Aluminum door return grille with sight-proof blades parallel to short dimension. Damper body formed in langed Z sections 52 x 35 x 196. Lorient offers a range of cover grilles for its intumescent air transfer grilles. 53. With high quality and competitive pricing these grilles form the back bone of a standard offering that will meet any application requirements. Static Pressure 100. NR Ratings and Core Areas Air Volume m3/s Face. Habitable rooms only shall be required to meet these requirements forEngera Bathroom Door Air Vent Grille Two Sided Ventilation Cover for Restroom, Warehouse, Storage Doors | Interior Door Transfer Grill 453mm x 91mm (18. Typical Building Sector : Commercial,Dom. 2. Click here to download. fitting a conventional grille to a wall or door will totally negate other measures taken to prevent the spread of fire, hot smoke andGrilles Type AH · WAP · AF Installation situation Type AH, AF ≥X Nomenclature ‡ in l/s/m based on 1000mm nominal grille length . 006 0. Length : 80 mm. transfer of room air to another, i. Minimum size is 6" x 4" (152 x 102). Download catalogue. Use two needle nose pliers and adjust the louvers to a more open position. The problem is that sound (and a small amount of light) pass freely through the vents negating all privacy of closing the door. 19. Manufactured using modern<br />. A high performance, standard vision intumescent air transfer grille for walls, doors and ventilation ducts. This grille features a 3/64” thick perforated face with 1/8” holes on staggered centers. jpg. Submit a request online and get a quote from your local representative within 4 hours. Gilberts NV Series provides a comprehensive and traditional range of vision proof grilles to suit all manner and type of air transfer application through doors, walls and partitions. uk. H Nominal grille heigh t. 008 0. Series AV Door Transfer Grille. air transfer grilles can be used in all applications where cold smoke containment is required. With. Countersunk holes. Static Pressure 100. A rater-measured pressure differential of ≥ -5 Pascals and ≤ +5 Pascals (0. Please watch our corporate video. Both the Halton TVC grille and opposite frame are screwed to the wall or door. Where was Gilles Gilbert born? Gilles Gilbert was born in St-Esprit, Canada. 1 800 222 5932. Series XG-DG extruded aluminum door grilles are designed to transfer air through doors or walls. Apply a bead of Pyroplex Intumescent Acrylic Sealant centrally and spread the acrylic across the full width of timber liner, to achieve a thickness of 0. 02576. - Wide 33mm Flange Border. JPG. On the roof, 3 number penthouses, ranging from 1m x 1. NEWS. VAT Number: GB 154 1026 07. The 61DG Series Door Grille may also be used as a transfer grille and in place of standard design exhaust and return air grilles where it is important that the interior of the plenum or duct be concealed. Compare. Specifications - Gilberts (Blackpool) EN English Deutsch Français Español Português Italiano Român Nederlands Latina Dansk Svenska Norsk Magyar Bahasa Indonesia Türkçe Suomi Latvian Lithuanian český русский български العربية Unknown Clifton Rd, Blackpool, FY4 4QT. Width : 1025 mm. Cover grille (not included) Duct SERIES FB Door, Wall & Partition Mounting Intumescent Fire Dampers Gilberts FB Series provides a compact, eficient range of intumescent ire dampers designed to satisfy all types of air transfer application in ofices, shops, schools, hospitals and many other commercial projects. AG30 Bar Grille. jpg. F. METALAIRE Steel Return Grille - 45° Louvered Face - Surface Mount - Model SRH-1. Conditioned air supply sized to deliver at a rate equal to 1 cubic foot per minute (0. A jump duct is a short piece of insulated flex duct. 0 ( 0) From £45. 14" x 14" White Aluminum Transfer Door Grille w/ Frame (TGF Series) Compare. Save4. HVAC OV 17. 5m/s and NC level less than 15. SCHAKO sight-proof transfer grilles are overflow grilles for walls and doors and are used between two adjacent rooms for pressure compensation.