Trickle air vents for windows are small but vital components that allow a constant, gentle stream of outside air to enter a room, even when the window is closed and locked. As modern buildings become more airtight to save energy, these vents provide the essential background ventilation needed to control humidity, remove indoor pollutants, and maintain a healthy living environment. Our uPVC trickle vents are designed to fit neatly into a routed slot in the window frame or sash, sitting almost flush with the profile and blending discreetly into the overall window design.

Each vent is extruded from UV-stabilised, impact-resistant uPVC that maintains its colour and structural integrity for decades. The built-in slider lets the occupant adjust airflow from fully open to fully closed, while an insect mesh and a rain baffle prevent bugs and water from entering the home. The vent is compatible with both aluminium and uPVC window frames, making it an ideal accessory whether you are fabricating high-performance thermal break aluminium windows or standard residential units.
Shengxin, with 29 years of experience in aluminium extrusion and global fenestration supply, stocks these trickle vents as part of a comprehensive range of window accessories. By ordering vents together with your aluminium window profiles, you simplify procurement, reduce shipping costs, and gain a single point of contact for after-sales support. Every shipment includes the necessary installation hardware, end caps, and documentation to demonstrate compliance with EN 13141-1 and national building ventilation standards.
Features & Benefits
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Universal slot compatibility: Manufactured to fit 12mm or 14mm routed slots — the two most common cutters used across aluminium and uPVC window fabrication machinery. No special tooling changes are required to integrate these vents into your production line.
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Adjustable, draught-free airflow: A smooth-action slider allows the room occupant to set the desired ventilation level. The air enters through a baffled canopy that directs the flow upwards, preventing cold draughts at body level while still refreshing the room.
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Proven weather resistance: An integrated insect mesh and a self-draining rain baffle ensure that the vent performs reliably in all weather conditions, from driving rain to high winds, without letting water or debris into the window frame.
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Helps meet building ventilation requirements: With certified equivalent areas of 2500, 3500, or 5000 mm² depending on length, these vents provide the background ventilation rates specified in UK Approved Document F, EN 13141-1, and similar international codes.
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Low-maintenance, durable construction: The uPVC body is UV-stabilised and will not rust, corrode, or need painting. An occasional wipe of the external grille is the only maintenance required for the full life of the window.
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Quick snap-fit or secure screw-fix: Installers can choose a snap-fit for rapid assembly on the production line, or a screw-fix option for added security in high-traffic or accessible locations. All screws and end caps are colour-matched and supplied in the box.
Vent Selection & Building Regulation Compliance
Use this guide to select the correct vent length and quantity to meet typical background ventilation requirements. Equivalent areas are measured according to EN 13141-1.
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Room Type
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Recommended Equivalent Area
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Vent Configuration
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Regulation Reference
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Habitable Room (Bedroom, Living Room)
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5000 mm²
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One V-450, or two V-250s (one each end)
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UK AD F, EN 13141-1
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Kitchen (with mechanical extract)
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2500 mm²
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One V-250
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UK AD F
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Utility / WC
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2500 mm²
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One V-250
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EN 13141-1
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Open-Plan Living Area
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8000 mm²
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One V-450 + one V-350, or four V-250s
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UK AD F, local code
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Equivalent area values are approximate. For precise calculations, refer to the test certificate provided with each vent model. Vents can be combined to achieve higher total equivalent areas.
Technical Specifications
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Material
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UV-stabilised uPVC (unplasticised polyvinyl chloride), impact-resistant grade
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Available Lengths
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250 mm, 350 mm, 450 mm (standard); custom lengths up to 1000 mm
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Slot Width
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12 mm or 14 mm (specify when ordering)
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Equivalent Area (EQA)
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~2500 mm² (250 mm) / ~3500 mm² (350 mm) / ~5000 mm² (450 mm) per vent
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Colour Options
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White (RAL 9016), Brown (RAL 8014), Beige (RAL 1015); custom RAL matching available
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Installation
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Snap-fit or screw-fix into routed slot in frame or sash head; screws and end caps included
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Weather Protection
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Integrated insect mesh and self-draining rain baffle; tested under dynamic water penetration
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Compliance
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EN 13141-1, CE marked; conforms to UK AD F, ASHRAE 62.2, and similar international ventilation standards
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Recommended Installation Positions by Window Type
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Window Type
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Recommended Vent Position
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Installation Notes
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Casement / Side-Hung
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Head of outer frame or sash
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Ensure the slot does not interfere with hinges or locking mechanism
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Tilt & Turn
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Head of outer frame (fixed frame, not sash)
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Routing into the outer frame avoids complications with the tilt mechanism
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Fixed Light
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Top rail of frame
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Ideal location for maximum airflow; can be installed centrally or at corners
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Sliding Window
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Head of fixed outer frame
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Do not install on moving sash to avoid catching during operation
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The vent should always be positioned at the highest practical point in the frame head to encourage natural convection — warm air rises, and fresh incoming air will mix before descending to occupant level.
Customisation & Supply Options
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Service
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Capability
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Custom Vent Lengths
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Any length from 200 mm to 1000 mm can be produced to order
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Bespoke Colour Matching
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Custom RAL colours to match aluminium frame powder coat or foil finishes
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Slot Width Variations
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12 mm and 14 mm as standard; other widths available for volume orders
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Bulk Packaging & Kitting
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Vents packed in boxes of 50 or 100; can be consolidated with aluminium profile orders for single delivery
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Documentation Package
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EN 13141-1 test reports, CE Declaration of Performance, and installation instructions provided
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Sampling Service
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Trial samples available for evaluation before committing to full production order
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Why Buy Trickle Vents from Shengxin?
As a leading aluminium extruder with 29 years of experience, Shengxin supplies not only precision aluminium window and door profiles but also the essential accessories that make those windows compliant and comfortable. Our trickle air vents for windows are sourced from audited uPVC manufacturing partners and stocked in our 5,000-ton warehouse, ready to be added to your next profile order. One purchase order, one consolidated shipment, one reliable partner — that is the advantage of working with Shengxin.
Reliable Stock Availability
We keep buffer inventory of standard white and brown vents in all three lengths. Rush orders and mixed schedules can often be dispatched within days.
Audited Quality
Every batch of vents is checked for dimensional accuracy, slider operation, and colour consistency. Test certificates are available for every shipment.
Consolidated Global Shipping
Add vents to your aluminium profile container. We optimise the packing to ensure everything arrives together, reducing your freight costs and carbon footprint.
Technical & Compliance Support
Our team can help you calculate the required equivalent area for your window schedule and provide the documentation needed for building control approval.
Your fenestration partner, not just a profile supplier: $120 million in assets, 100,000-ton annual extrusion capacity, exports to 97 countries. 5 container loading platforms and a 5,000-ton warehouse ensure your orders leave on time.
Trickle Air Vents for Windows FAQ
Q: What size trickle vent do I need for a standard bedroom window?
A: For a typical bedroom, building regulations usually require around 5000 mm² of background ventilation. This can be achieved with a single 450mm vent (V-450) or two 250mm vents (V-250) — one at each end of the frame head. Using two vents can improve air distribution, especially in wider windows.
Q: Can trickle vents be installed in existing windows, or only during fabrication?
A: While it is technically possible to retrofit a trickle vent into an existing window by routing a slot on-site, we strongly recommend installing vents during the window fabrication process. This ensures accurate slot dimensions, clean cut edges, and proper sealing. Retrofitting is more labour-intensive and carries a higher risk of damaging the frame finish or glazing.
Q: Will these vents cause a whistling noise in windy conditions?
A: No. The internal baffle design breaks up the airflow and prevents the resonance that causes whistling. Additionally, the insect mesh and inlet grille diffuse the incoming air. Our vents have been tested under various wind speeds and are designed to operate quietly throughout their adjustment range.
Q: Do these vents affect the security of the window?
A: The vent is too small for a person to pass through, and the internal baffle and mesh prevent access with tools. When fitted into the frame head, the vent does not compromise the locking points or the structural integrity of the window. For ground-floor windows, the screw-fix version provides an additional level of tamper resistance.
Q: Can I order a mixed schedule of lengths and colours?
A: Yes. We encourage you to specify exactly the lengths and colours needed per window type. We will pack and label each item clearly, so your fabrication team can identify the correct vent for each window without confusion.
Custom Trickle Vent Options
If your project requires a non-standard vent length, a custom RAL colour, or a specific slot width not covered by our standard range, Shengxin can arrange custom-manufactured trickle air vents through our specialist uPVC extrusion partners — delivered with the same reliability as our aluminium profiles.
How It Works:
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Tell us your specification — vent length, slot width, RAL colour, and estimated annual usage.
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We engage our uPVC partner — a custom extrusion run is set up, and pre-production samples are manufactured.
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Receive a quotation — covering unit price, any one-off tooling costs, and lead time.
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Approve the sample — we ship physical samples for your fit, colour, and airflow performance approval.
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Full production & delivery — vents are manufactured, packed, and delivered on your schedule, with full documentation.
⚠️ Important Note: All vent images and dimensional drawings on this page are for reference only. Final dimensions, colour, and equivalent area will be confirmed in your order specification and pre-production sample. Please contact our team to discuss your project requirements before placing a custom order.
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| Related products: Aluminum Window & Door Profiles, Thermal Break Aluminum Profile, Window & Door Accessories