Streaming windows, musty corners and black mould are signs that a room is holding more moisture than it should. In modern, well insulated homes the warmth is great for comfort, but humidity can build unless there is a controlled path for it to escape. Passyfier Dehumidifier Vents create that path. They use natural vapour diffusion to move moisture through the wall quietly and continuously, with minimal draughts and very little heat loss. There are no fans, no electrics and no controls to worry about. This guide explains what causes everyday condensation, how Passyfier vents help, and where they work best. You will see the key differences between the models we stock so you can match each vent to the size and use of the room. We also cover clear, step by step installation for both sleeved and core drilled versions, plus simple aftercare, so you get effective condensation control and background ventilation without complexity. At Platinum Chemicals Ltd, we supply the an extensive Passyfier Dehumidifier Vent range and related condensation control products. If you are unsure which model to choose, our team is here to help you select the right vent for a tidy, reliable result that keeps rooms drier and more comfortable all year. Why Treating Condensation And Mould Matters Condensation is simply water vapour settling on the coldest surfaces in a room. In well insulated homes, those cold spots are often window panes, outside corners and behind furniture. Left alone, this regular wetting creates the ideal conditions for black mould to grow. Condensation on window glass indicating excess indoor humidity and poor ventilation Mould is more than a cosmetic problem. Spores and musty by products can aggravate asthma and allergies, and they are unpleasant to live with. Repeated damp also damages paint and plaster, lifts wallpaper, stains sealants and can lead to swollen timber and corroded fittings. Over time you spend more on redecorating and repairs than on preventing the issue in the first place. Treating condensation early keeps rooms healthier and protects the building fabric. Good extraction in kitchens and bathrooms is vital for short bursts of steam, and steady background control in living spaces helps keep everyday humidity in check. Passyfier Dehumidifier Vents provide that background pathway, allowing moisture to disperse quietly and continuously so surfaces stay drier and mould is less likely to return. How Passyfier Dehumidifier Vents Work Passyfier vents use natural vapour diffusion. Indoors, air usually carries a higher vapour pressure than outside, especially in the heating season. The vent creates a controlled path through the wall so moisture molecules migrate outward on their own, without fans or electrics. In sleeved models such as the Passyfier 230 and 75AB, a warm telescopic sleeve houses a dense mineral wool core. This core is effectively open to water vapour yet resists direct through draughts, so humidity can escape while bulk airflow is kept low. In core drilled models such as the Passyfier 100 and 140, a warm lined tube performs the same role and the shaped external cowl moderates wind pressure at the outlet. Because diffusion rather than airflow does the work, the process is silent and continuous, with minimal felt movement of air and very little heat loss. Fitted high on an external wall, the vent taps into the warmest, most moisture laden air near the ceiling and quietly helps keep surfaces drier day after day. Key Features And Advantages Passyfier vents are designed to make day to day living more comfortable without adding complexity. They work continuously in the background to help keep humidity in check, reducing window streaming and the cold corner mould that often appears in well insulated homes. Because they rely on natural vapour diffusion rather than fans, there is no noise and no need to adjust settings. Installation is straightforward and tidy. Sleeved or core drilled options allow you to match the vent to the room and wall type, and the supplied grilles and cowls keep draughts to a minimum. Ongoing care is simple, usually just a quick wipe of the internal grille, so you get long term performance with virtually no maintenance. ✔️ Silent, always on operation with no power requirement. ✔️ Reduced condensation on glazing, cold corners and thermal bridges. ✔️ Anti draught detailing that minimises heat loss and discomfort. ✔️ Quick, tidy retrofit with supplied grilles, cowls and sleeves. ✔️ Low maintenance, just an occasional wipe of the internal grille. ✔️ Designed to complement, not replace, kitchen and bathroom extract fans. Where Passyfier Vents Work Best And Where They Should Not Go Fit the vent high on an external wall in the room that actually has the problem. Keep the top of the internal grille within about 300mm of the ceiling so it captures the warmest, most moisture laden air. Choose the colder, stale corner rather than near the doorway, and keep curtains, wardrobes and furniture clear of the grille. In larger or open plan rooms, two vents on opposing walls improve distribution and overall effectiveness. You can fit at low level if high level placement is impossible, but performance is reduced, in some cases by around half, so high level is preferred. Internal Grille of a Passyfier 100 Installed Approx 300mm Below Ceiling Height Do not use Passyfier vents to supply combustion air for gas, oil or solid fuel appliances. They are not a replacement for compliant extractor fans in kitchens and bathrooms. In wet rooms, retain the fan for short bursts of steam and, if a vent is also needed, place it diagonally opposite the extractor and keep at least 1.5m away from a cooker hood. Always set a slight outward fall through the wall so any incidental moisture drains outside, and seal across open cavities on the room side so air cannot bypass the diffusion path. The Passyfier Models We Stock Passyfier 230 Sleeved A high capacity, sleeved vent for standard rooms up to 20m². It fits a nominal 225×150mm opening, which is the size of a 9×6 inch airbrick, and arrives with a pre fitted external airbrick in a choice of colours plus a louvred internal plastic grille with flyscreen. The telescopic sleeve adjusts from 240–340mm to suit most walls, and an optional Extension Sleeve adds a further 112mm where walls are deeper. In typical domestic conditions the unit can transmit up to 2.3L of moisture per 24h. A wind blast cowl is available for very exposed sites. Choose this model when you want a neat airbrick replacement with strong background capacity and minimal draught. Passyfier Core 100 A compact, core drilled vent for small rooms up to 7m². Installation is by a 132mm core hole that accepts a 128mm outer tube. The telescopic tube set adjusts from 240–440mm, and the kit includes a plastic wedge to set a slight outward fall. An aerodynamic external cowl limits draughts and heat loss, and a white internal grille with integrated flyscreen gives a clean finish. Moisture transmission is up to 1L per 24h. This is a practical choice where a tidy circular opening is preferred in solid, cavity or timber frame walls. Passyfier Core 140 A larger core drilled option for rooms up to 10m². The wall opening is made with a 162mm core bit and the main outer tube is about 154mm in diameter. The robust telescopic set adjusts from roughly 250–410mm to match common wall thicknesses. An external contoured cowl improves comfort in windy locations, and the white internal grille with flyscreen is easy to clean. Typical moisture transmission is up to 1.4L per 24h. Pick this model when you need a little more capacity than the Core 100 while keeping a circular core installation. Passyfier Sleeved 75AB A slim, sleeved vent for very small spaces such as cupboards, box rooms and utility stores up to 5m². It fits a neat 9×3 inch opening and comes with a slim external louvred airbrick face about 210×65mm, a white internal grille with flyscreen and a telescopic sleeve for 100–345mm wall thicknesses. A supplied wedge helps you set the outward fall. In typical conditions it can transmit up to 0.75L per 24h. Use this model where you want targeted background drying in compact areas with a discreet airbrick style finish. Choosing The Right Passyfier Model Start with room size, then consider the wall opening you prefer to make. If you are replacing an existing 9×6 inch airbrick, a sleeved model that fits the rectangular opening is usually the neatest choice. If you want a tidy circular hole formed with a core drill, pick a core model. Always fit the vent high on an external wall in the room that actually has the problem. Passyfier 75AB Choose this for very small spaces up to 5m², such as cupboards, box rooms and utility stores. It fits a neat 9×3 inch opening and the telescopic sleeve covers roughly 100–345mm wall thicknesses. In normal conditions it can transmit up to 0.75L per 24h. It is ideal when you want a discreet airbrick style finish and targeted background drying. Passyfier 100 Pick this for compact rooms up to 7m² where a round core drilled opening is convenient. Installation uses a 132mm core bit and a 128mm outer tube, with a telescopic set that adjusts about 240–440mm. Capacity is up to 1L per 24h. It suits solid, cavity and timber frame walls and is a tidy option for small bedrooms and studies. Passyfier 140 Use this where you need a little more capacity in rooms up to 10m², still with a circular core installation. Drill a 162mm core and fit the robust telescopic tube set, which adjusts roughly 250–410mm. Typical transmission is up to 1.4L per 24 hours. The shaped external cowl helps moderate wind effects, which is useful in exposed positions. Passyfier 230 Choose this for larger habitable rooms up to 20m² or when replacing a standard 9×6 inch airbrick. It fits a nominal 225×150mm opening, has a warm telescopic sleeve adjustable from 240–340mm, and an optional extension sleeve adds 112mm for deeper walls. Capacity is up to 2.3L per 24h. A wind blast cowl is available for very exposed sites and two units on opposing walls can help in bigger open plan spaces. If your room size sits on the boundary between two models, lean towards the higher capacity option or consider using two units on opposite walls to improve distribution. Installing Passyfier Dehumidifier Vents Read all safety guidance before you start. Wear eye protection, gloves and a dust mask. Check the wall for hidden services, lintels and damp proof courses. Always install high on an external wall, with the top of the internal grille within about 300mm of the ceiling. Set a slight fall to the outside so any incidental moisture drains out, and seal across open cavities on the room side to stop bypass draughts. Passyfier 230 (Sleeved, 9×6 Inch Opening) Mark the position inside at high level, then mark a 225×150mm rectangle on the outside face to suit a standard 9×6 inch airbrick opening. Cut the external opening neatly, clear debris and dress the edges. From indoors, cut the matching 225×150mm opening so both faces align. Dry fit the telescopic sleeve and set the length to suit the wall thickness (240–340mm as standard). If the wall is deeper, add the 112mm Extension Sleeve. Set a slight outward fall through the wall. Bed the sleeved assembly in place so the pre fitted external airbrick sits square and flush to the façade. Do not twist or compress the sleeve. If the sleeve crosses an open cavity, apply a continuous internal mastic seal around the penetration. Fix the internal louvred plastic grille with the supplied screws, make good and clean down. Treat any existing mould with a fungicidal wash before redecorating. Graphic of a Passyfier 230 When Viewing From The Exterior Passyfier 75AB (Sleeved, 9×3 Inch Opening) Mark the position inside at high level, then mark a neat 9×3 inch rectangle on the outside face. Cut the external opening, clear debris and square the edges. From indoors, cut the matching 9×3 inch opening so both faces align. Dry fit the telescopic sleeve and adjust to the wall thickness (100–345mm range). If the wall is thinner than the sleeve, trim the inner duct so both faces sit flush. Use the supplied wedge to set a slight outward fall through the wall. Bed the sleeved assembly, ensuring the slim external louvred airbrick sits level and tight to the façade. Seal across any open cavity on the room side with a continuous bead of mastic. Fix the white internal grille with built in flyscreen, make good and clean the work area. Passyfier 100 (Core Drilled, 132mm Hole) Mark a high level centre point inside and drill a small pilot hole to confirm the exterior location. Core drill a 132mm hole with a slight fall to the outside, then remove the core and clean the opening. Dry fit the telescopic tube set and adjust to the wall thickness (about 240–440mm). Trim the outer tube if the wall is thinner than the closed length. Insert the tube so it falls gently to the exterior. Keep the red inner base label at the bottom. Apply a continuous bead of silicone to the rear flange of the external cowl, position it level and fix with the colour matched stainless screws. Slide the inner tube home so the assembly is square and airtight. Seal any gaps if the wall is uneven. Fix the internal grille housing, then push fit the grille with flyscreen. Make good and clean down. Passyfier 100 When Viewing From The Exterior Passyfier 140 (Core Drilled, 162mm Hole) Mark a high level centre point and drill a small pilot hole to check the exterior position. Core drill a 162mm hole with a slight fall to the outside. Remove the core and clear debris. Dry fit the robust telescopic tube set and adjust to the wall thickness (about 250–410mm). Trim the outer tube if the wall is thinner than the closed length. Insert the tube on a gentle outward fall. Keep the red inner base label at the bottom. Run a bead of silicone on the rear flange of the external cowl, position it level and fix with the stainless screws supplied. Seat the inner tube so the assembly is square and sealed. Add sealant around the annulus if the construction is uneven. Fix the internal grille housing, clip in the grille with flyscreen, make good and clean down. Safety, Handover And Aftercare Work from a stable platform with good lighting and keep the area below clear. Wear eye protection, gloves, hearing protection for core drilling and a suitable dust mask. Scan the wall for hidden services and structural elements before any cutting. Control dust with careful technique and extraction where possible. Handle drills, cores, cement and sealants according to manufacturer guidance. If you are not confident with through wall work or large core drilling, engage a competent professional. At handover, explain that the vent is passive and always on. There are no switches or settings. Keep the internal grille uncovered and free from curtains, wardrobes or shelves. Continue to use extractor fans in kitchens and bathrooms during cooking and showering. Keep those doors closed while steam is present, then open them afterwards for cross ventilation. Wipe or lightly vacuum the internal grille and flyscreen once or twice a year and check the external cowl or airbrick after storms. Inspect exterior sealant every few years and renew if it shows cracking. If mould was present before installation, wash affected surfaces with a quality fungicidal wash and allow to dry fully before repainting. Maintain steady background warmth in colder months so indoor air can carry normal moisture without condensing on cold surfaces. Common Mistakes To Avoid Fitting the vent in the wrong room instead of the room with the problem. Mounting too low on the wall where warm, moist air is not captured. Forgetting the outward fall so incidental moisture cannot drain outside. Leaving an open cavity unsealed so air bypasses the diffusion path. Overtightening fixings and distorting the sleeve or tube set. Blocking the internal grille with curtains, furniture or stored items. Expecting the vent to replace extractor fans in wet rooms. Using the vent to supply combustion air to appliances. Quiet, Continuous Moisture Control You Can Fit In An Afternoon Passyfier Dehumidifier Vents provide a permanent, silent route for background moisture to escape. Choose the model that matches the room size, install high on an external wall with a slight fall to the outside and keep extractor fans for short term peaks. The result is drier air, fewer condensation problems and a home that stays fresher with virtually no maintenance. About Platinum Chemicals Ltd Platinum Chemicals is a family business with more than 40 years of experience supplying specialist products for damp proofing, waterproofing, condensation control and wood treatment. We stock trusted brands alongside our own ranges and provide practical guidance to help homeowners and trades solve moisture, mould and structural repair problems with confidence. Customers benefit from great service, free mainland UK delivery on orders over £100, and same day despatch when ordering before 2:00pm, terms apply. Our Condensation Control range includes Passyfier Dehumidifier Vents, Positive Input Ventilation Systems, Extract Fans, Anti Mould Coatings and accessories so you can choose a complete solution for a drier, healthier home. You can shop the Passyfier Range online with Platinum Chemicals for fast delivery across the UK.
