Passyfier Core 100 Vent

Health & Safety Considerations

Work from a safe platform with adequate guarding because core drilling and masonry cutting create dust and falling debris. Wear safety goggles, gloves, a dust mask, and suitable work clothing.

Confirm the position is clear of concealed services and structural elements before drilling. Keep the work area tidy, maintain good lighting, and control dust with careful technique and extraction where possible. Handle sealants in line with the manufacturer’s guidance and dispose of debris responsibly.

Site Preparation

Choose the room that is suffering from condensation and identify a high-level position on an external wall. The top of the vent should be no more than 300mm below the ceiling because this is where the warm, moisture-laden air pools. Placing the vent at this level maximises vapour diffusion and keeps any slight air movement away from occupants.

Aim for the colder corner furthest from the room entrance where problems are most evident. Where high-level fitting is impractical because of pipework or lintels, installation at low level around 300mm above the floor is acceptable, although performance is typically reduced.

In kitchens and bathrooms use compliant mechanical extract fans as the primary means of removing short-term peaks and, if possible, site the vent diagonally opposite the extractor. Assemble the tools and materials you will need, including a Ø132mm Core Bit, a drill with a suitable rig, a spirit level or straightedge, a sealant for the external cowl flange, stainless screws and wall plugs, and the plastic wedge supplied to create the outward fall.

Limitations And Good Practice

The unit provides passive background moisture control and is not a substitute for dedicated extract fans in wet rooms. It must not be used to supply combustion air for gas, oil, or solid-fuel appliances.

Fit the vent at high level wherever possible and keep soft furnishings, furniture and curtains clear of the grille. Always create a slight fall to outside so any incidental moisture drains outward, and seal neatly around the penetrations to prevent bypass draughts.

Step-By-Step Installation

1. Mark the internal position at high level in the affected room and check there is clearance from services and structural bearings. Measure from fixed references to transfer the centre to the outer face or drill a fine pilot hole through the wall to establish the datum from one side to the other.
   
   

2. Core drill a Ø132mm hole on a slight outward fall. Use the supplied plastic wedge to help you achieve a drop of at least 6mm across the wall thickness so any incidental moisture runs to the exterior. Dress the edges and remove dust and debris.
   
   

3. Adjust the telescopic tube set to suit the wall thickness. If the wall is less than 250mm thick, trim the outer tube on site so the assembly sits flush and square. Check that the red inner base label is located at the bottom of the duct when you insert the vent. This orientation ensures the internal components perform as intended.
   
   

4. Insert the tube assembly from inside and check the outward fall again. Offer the external cowl to the wall, apply a continuous bead of suitable silicone to the rear flange, and secure it to the outside face using the stainless steel countersunk 25mm fixing screws provided. Ensure the cowl sits level and tight to the façade.
   
   

5. Fit the internal grille housing and fasten it to the wall using the 19mm fixing screws provided. Push-fit the grille into its housing so it sits neatly. If you need to remove the grille in future, insert a flat blade between the grille and housing at the indicated point and deflect the top wall of the grille towards the centre.
   
   

6. Make good around the penetrations as required, clean the work area, and verify that the outward fall is present and the cowl and grille are secure.

Handover And Everyday Use

Explain to the occupier that the vent is a non-mechanical dehumidifier vent. It works continuously without power by allowing water vapour to diffuse outdoors while minimising draughts and heat loss.

There are no controls to operate. The grille should remain uncovered and free from obstructions. In kitchens and bathrooms they should continue to use their extractor fans during cooking and showering and keep internal doors closed until steam has cleared.

Maintenance

The vent has no moving parts. Once or twice a year, wipe or lightly vacuum the internal grille and flyscreen to remove dust and cobwebs. Check that the external cowl is free of debris after storms. There is no filter to replace and no running cost to consider.

Aftercare

If the room previously suffered mould, wash affected surfaces with a quality fungicidal wash and allow to dry fully before redecorating. Maintain steady background heat during colder months so indoor air can carry moisture without reaching saturation at cold surfaces. In larger open-plan areas, consider a second unit on the opposite wall to improve distribution. Keep soft furnishings clear of the grille so diffusion is not impeded.

Other Information

For maximum efficiency mount the unit at high level with the top within 300mm of the ceiling. One Passyfier Core 100 serves up to 7m² of floor area, so larger rooms may require more than one vent.

The system consists of a telescopic tube set that adapts to common wall thicknesses, a white internal grille with integrated flyscreen, and an external cowl available in a choice of colours. Installation time is reduced because the wall opening is formed with a Ø132mm Core Bit.

The product works passively 24 hours per day, makes no noise, and has no moving parts. It reduces draughts and heat loss whilst still providing background ventilation and it costs nothing to run.

Q) What is the Passyfier Core 100 Dehumidifier Vent and what problem does it solve?

A) The Passyfier Core 100 Dehumidifier Vent is a through-the-wall, non-mechanical ventilation device for small rooms where window streaming, cold-corner condensation and black mould occur. Instead of using a powered fan, it works passively 24/7 by allowing water vapour to diffuse to the outside, trimming indoor relative humidity towards a healthier band with zero running cost or noise. One unit serves rooms up to 7m² and, in typical domestic conditions, can transmit up to 1 litre of moisture per 24 hours. By steadily reducing background humidity it helps prevent surfaces from repeatedly reaching dew-point, which is the root cause of mould staining and musty odours. The aerodynamic external cowl and internal grille resist bulk airflow, so the vent minimises draughts and heat loss while still enabling vapour migration. The result is a discreet, fit-and-forget solution that improves comfort and protects décor and building fabric in bedrooms, nurseries, home offices and small box rooms.

Q) How does the Passyfier Core 100 Dehumidifier Vent work without a fan or electrics?

A) The Passyfier Core 100 relies on natural vapour-pressure differences, which are typically higher indoors than outdoors during the heating season. Moisture molecules migrate from the warm, moist interior towards the cooler exterior through the vent’s warm, lined tube. The external cowl is shaped to resist direct through-draughts, and the internal grille with flyscreen further tempers airflow, so the mechanism is vapour diffusion rather than bulk air exchange. Because diffusion is a molecular process, the vent operates silently and continuously with negligible energy penalty, unlike open airbricks that admit cold air freely. This steady migration lowers indoor humidity between moisture events such as bathing and cooking. It complements extractor fans by managing background moisture in the hours when fans are not running, keeping relative humidity more stable and less prone to causing condensation at cold surfaces.

Q) Where should the Passyfier Core 100 Dehumidifier Vent be installed for best results?

A) Site the Passyfier Core 100 at high level on an external wall in the problem room, with the top of the unit no more than about 300 mm below the ceiling. Warm, moisture-laden air pools near the ceiling, so high-level placement maximises vapour diffusion while keeping any felt air movement away from occupants. Choose the colder, stale corner furthest from the door if possible, and avoid placing the internal grille behind curtains, wardrobes or wall units that could obstruct diffusion. In open-plan areas, fit the unit on the side most affected by condensation risk, and consider a second vent on the opposing wall if the floor area exceeds 7m². In kitchens and bathrooms retain compliant local extract; the Core 100 is intended for bedrooms, nurseries, home offices and small living spaces where background moisture builds up after insulation and glazing upgrades. Always set a slight outward fall so incidental moisture drains outside.

Q) What room size does one Passyfier Core 100 Dehumidifier Vent cover, and when would I need more than one?

A) The Passyfier Core 100 is optimised for compact rooms up to 7m², such as small bedrooms, nurseries and box rooms that often show condensation first. In a space within this size range a single unit can transmit up to 1 litre of water vapour per day under typical domestic conditions, which is sufficient to stabilise relative humidity between peak events. If the room is notably larger than 7m², very cluttered, unusually cold, or open to adjoining areas, consider installing a second vent on an opposing wall for better distribution. In homes with several affected rooms, treat the worst space first, then reassess after a heating cycle or two before adding further units. Remember that the vent manages continuous background load; you should still operate bathroom and kitchen extract fans during moisture-producing activities to clear short-term spikes quickly.

Q) Will the Passyfier Core 100 Dehumidifier Vent cause uncomfortable draughts or noticeable heat loss?

A) The Passyfier Core 100 is deliberately engineered to minimise draughts and thermal penalty while enabling moisture diffusion. The external cowl’s aerodynamic form and the internal grille resist bulk airflow, so you do not get a free jet of cold air as you might through an open vent. Fitted at high level, any moderated air movement is kept well above seating height, reducing perceived draught. The lined tube helps maintain a warm pathway, which limits heat loss compared with uncontrolled openings. Correct detailing is essential: set a small outward fall, seal neatly around the penetrations, and keep the grille unobstructed. In practice, rooms feel less clammy and recover faster from overnight cooling, and occupants find they can keep the vent in service year-round without the discomfort that leads to vents being blocked.

Q) Does the Passyfier Core 100 Dehumidifier Vent replace kitchen and bathroom extractor fans?

A) No. The Passyfier Core 100 provides passive background dehumidification and is not a substitute for rapid mechanical extraction at source. Kitchens and bathrooms generate short-term, high-intensity humidity that needs to be discharged to outside quickly by compliant extract fans. The Core 100 handles the ongoing humidity that lingers after those events, keeping bedrooms and small living spaces drier through the evening, night and early morning. This combination mirrors good building-services practice: use local extract during cooking and showering with doors closed, then rely on the Core 100 to manage the background load quietly and continuously. Together they help prevent window streaming, reduce mould risk and protect finishes without adding to energy bills.

Q) What comes in the Passyfier Core 100 Dehumidifier Vent kit, and what tools are needed?

A) The Passyfier Core 100 kit includes a telescopic tube set sized for a Ø132mm core-drilled opening, a white internal grille with an integrated flyscreen, a colour-matched external cowl and wall plate, stainless fixing screws with colour-matched heads for a neat exterior finish, and a plastic wedge to help set the correct outward fall. Installation instructions are supplied. A competent installer will typically use a 132mm Core Bit with an appropriate drill and rig, a spirit level or straightedge, sealant for the external flange, suitable wall plugs, and hand tools for fixing and making good. The telescopic range covers 240–440 mm wall thicknesses; if your wall is thin, the outer tube can be trimmed on site to sit flush and square. The design is suitable for solid masonry, cavity walls and timber-frame constructions.

Q) What are the key technical details and performance figures for the Passyfier Core 100 Dehumidifier Vent?

A) The Passyfier Core 100 operates on passive vapour diffusion through a warm, lined duct, with an external cowl to limit bulk airflow and an internal grille with flyscreen to keep the opening clean. The maximum served floor area is 7m² per vent, and under typical domestic conditions the unit can transmit up to 1 litre of moisture per 24 hours. The tube assembly takes a Ø132mm core-drilled hole and accepts a 128 mm outer tube, with telescopic adjustment from 240 to 440 mm to suit common wall thicknesses. The internal grille is approximately 200 × 200 × 30 mm and finishes the opening neatly. The device is non-mechanical, silent in operation and has zero running cost. Good practice includes high-level placement, a slight outward fall, and continued use of mechanical extract in kitchens and bathrooms for short-term moisture peaks.

Q) How is the Passyfier Core 100 Dehumidifier Vent installed, step by step?

A) Mark a high-level position in the affected room, ensuring clearance from services and structural bearings, then transfer the centre to the outside or drill a fine pilot to set a datum. Core drill a Ø132mm circular opening with a slight outward fall; the supplied plastic wedge helps you achieve a small drop across the wall thickness so incidental moisture drains outside. Adjust the telescopic tube set to suit the wall; where the wall is thinner than about 250 mm, trim the outer tube so the assembly sits flush and square. Insert the tube from indoors, checking that any orientation label faces down, then offer the external cowl, apply a continuous bead of suitable silicone to the rear flange, and secure it with the colour-matched stainless screws. Fit the internal grille housing, fasten to the wall, and push-fit the grille neatly. Make good as required, clean down, and verify the outward fall and secure fixings before handover.

Q) On what wall types can the Passyfier Core 100 Dehumidifier Vent be used, and are there any siting cautions?

A) The Passyfier Core 100 is suitable for solid masonry, cavity walls and timber-frame constructions, making it practical for both retrofit and new-build. In cavity walls, keep the core cleanly drilled and the tube continuous across the cavity to avoid bypass draughts; a neat seal around the wall plate and cowl flange prevents air leakage. In timber-frame, observe the sheathing and weather-barrier details and seal carefully to maintain envelope integrity. Always install near ceiling level in the problem room, keep soft furnishings clear of the grille, and avoid siting close to heat sources that could distort plastic components. Maintain separation from cooker hoods and ensure the exterior cowl has a clear, unobstructed path to atmosphere for reliable diffusion in all seasons.

Q) What day-to-day maintenance does the Passyfier Core 100 Dehumidifier Vent require?

A) The Passyfier Core 100 has no moving parts, filters or controls, so upkeep is minimal. Once or twice a year, lightly vacuum or wipe the internal grille and flyscreen to remove dust and cobwebs that could impede diffusion. After storms or heavy leaf fall, take a quick look at the external cowl to ensure the opening is clear. There is no electrical safety check because the device is non-mechanical and has no power supply. If you redecorate, keep paint and sealant away from the grille slots and cowl apertures. Provided the grille remains unobstructed and the outward fall is intact, the vent will continue to operate silently for many years without further attention.

Q) Are there any limitations to the Passyfier Core 100 Dehumidifier Vent that I should be aware of?

A) The Passyfier Core 100 is intended for passive background moisture control in small rooms and must not be used to supply combustion air to gas, oil or solid-fuel appliances. It does not replace the need for compliant mechanical extract in kitchens and bathrooms, which handle short-term humidity spikes. If the property has liquid water problems such as leaks, rising damp or penetrating damp, those defects must be rectified first; the vent addresses airborne moisture, not bulk water. Performance is reduced if the internal grille is obstructed by curtains, furniture or heavy dust build-up, or if the tube lacks an outward fall. In very large or open-plan rooms, fit more than one unit to match the floor area. Following these constraints preserves comfort and ensures reliable dehumidification.

Q) What practical tips will maximise performance from a Passyfier Core 100 Dehumidifier Vent?

A) Mount the vent high so the top sits within 300 mm of the ceiling, and keep the internal grille clear of curtains, pelmets and furniture to maintain free diffusion. During installation, use the supplied wedge to set a small outward fall and seal neatly around the cowl to avoid bypass draughts. Run bathroom and kitchen extract fans diligently during showers and cooking with doors closed, then open for cross-ventilation once steam has cleared. Maintain steady background heat in colder months so indoor air can carry moisture without reaching saturation at cold surfaces. In larger rooms or stubborn cases, add a second unit on the opposing wall to improve distribution. If the room previously had mould, treat with a quality fungicidal wash before repainting so you start from clean, dry surfaces.

Q) How quickly should I expect to notice improvements after fitting a Passyfier Core 100 Dehumidifier Vent?

A) Many households notice that morning window streaming reduces within the first week, particularly during colder spells when condensation risk is highest. Black mould is slower to respond because staining must be cleaned and surfaces redecorated after treatment; the vent’s role is to reduce the underlying humidity so the problem does not quickly return. Give the system a full heating cycle or two while following good housekeeping—use of extract fans, door management during moisture events and stable background heating. In very cold weather or larger, cluttered rooms, consider adding a second unit to accelerate stabilisation. If results are not evident after a few weeks, check that the grille is unobstructed, the cowl is clear, and the tube has an outward fall, then review extract-fan usage and heating patterns.

Q) Can the Passyfier Core 100 Dehumidifier Vent be colour-matched externally and will it look discreet indoors?

A) Yes. The external cowl is available in a range of colours to complement common façades, and the supplied stainless fixing screws have colour-matched heads for a tidy finish. The circular core-drilled opening keeps the outside detail compact and easy to make good around brick, render or cladding. Indoors, the crisp white grille with integrated flyscreen presents a simple, neutral appearance that blends with most décor and is easy to keep clean with a light wipe or vacuum. Because the unit is compact and located near the ceiling, it is unobtrusive in day-to-day use. With careful siting and neat sealing, most installations look like a purposeful architectural detail rather than an add-on.

Q) How does the Passyfier Core 100 Dehumidifier Vent compare with leaving a window on trickle or using an open airbrick?

A) Leaving a window on trickle or relying on an open airbrick invites bulk airflow, which can create uncomfortable draughts, discourage use in winter and lead occupants to block vents entirely. The Passyfier Core 100 is designed to allow moisture vapour to escape while resisting free through-draughts, using an aerodynamic cowl and internal grille to temper air movement. As a result it operates comfortably year-round and continues working at night when condensation risk peaks, with no user intervention. It also maintains a warm, lined pathway through the wall that limits heat loss compared with uncontrolled openings. In practice this means better compliance by residents, more consistent humidity control and reduced risk of mould without sacrificing comfort or security.

Q) Is the Passyfier Core 100 Dehumidifier Vent suitable for both retrofit and new-build projects?

A) Yes. The Ø132mm core-drilled opening and telescopic 240–440 mm tube make the Passyfier Core 100 quick to install in existing homes with solid, cavity or timber-frame walls, and the colour-matched exterior options help it blend with established façades. In new-build or conversion projects it provides a low-energy, silent background dehumidification measure for small rooms that are prone to condensation after fabric upgrades. It is particularly useful where airtightness and insulation improvements have increased condensation risk in compact bedrooms and study spaces. Include it as part of a whole-house strategy that also features compliant mechanical extract in wet rooms and sensible occupant guidance on heating and ventilation. With correct siting and detailing, the vent offers durable, maintenance-light moisture control for the long term.

Technical Data Sheet