BIOKIL. Passyfier Vent

BIOKIL. Passyfier Vent – passive dehumidifier vent for condensation control

BIOKIL. Passyfier Vents are passive dehumidifiers. Each one combines a through-the-wall, ‘warm’ telescopic sleeve with a slab of mineral wool inside, a louvered internal vent and a suitable external cover. The mineral wool lets moisture vapour out while preventing cold draughts, so occupants are not tempted to block the vents up.

Passyfiers take advantage of the differential partial moisture vapour pressure, which is normally higher inside an occupied building than outside, with little or no heat loss. They can easily be retrofitted in response to condensation call-outs, during refurbishment programmes, or installed directly in new build. A typical house needs about four or five units, and an existing 9” x 6” airbrick is often replaced with a Passyfier MK1.

Key features

• Continuous, silent operation 24 hours per day
• Can extract up to 2.3 litres of water per day, even at low vapour pressures
• Little or no heat loss – works passively on vapour pressure difference
• Draught-free – mineral wool avoids undue draughts, so vents are not blocked up
• Effective area well in excess of the 8,000mm² Building Regulations minimum for background ventilation
• Easily retrofitted or installed directly in new build

Typical applications

• Continuous background ventilation of habitable rooms
• Retrofitting in response to condensation and mould problems
• Refurbishment programmes
• New build
• Replacing an existing 9” x 6” airbrick
• Kitchens and bathrooms, together with mechanical extraction

Kit contents

• Main Passyfier Vent
• Extension sleeve
• Internal grille (always in white) and fixings
• Installation and fitting instructions

Retrofit fixing

1. Wear suitable clothing, safety goggles and gloves. Check the location is not obstructed by pipes, cables or load-bearing lintels.
2. Cut a 9” wide x 6” high aperture in the outside masonry (the polystyrene packaging makes an ideal template on rendered walls). Drill pilot holes in each corner from outside, and cover the cavity before completing the cut from inside.
3. Cement the external airbrick and internal slider duct level with each other so the main duct slopes outwards, with the main duct in position to prevent distortion. In open cavities, provide a continuous internal mastic seal where the slider crosses the main tube.
4. Fix the louver cover with the screws and plugs provided.
5. Before redecorating, wash down mould-affected surfaces with a good quality fungicidal wash.

Positioning

• Install where problems are already evident – usually the cold, stale corner of the room – as far from the entrance door as possible, with the top of the vent 300mm from the ceiling (or 300mm above floor level if impractical)
• Kitchen: ideally a cooker hood with extractor vented outside, plus a Passyfier diagonally opposite in an outside wall, not less than 1.5m from the extractor
• Bathroom: ideally a mechanical extractor fan, plus a Passyfier diagonally opposite in an external wall

Diffusion is slow compared with mechanical ventilation and will not cope with large amounts of water vapour produced over a short time in kitchens and bathrooms without additional mechanical ventilation.

Technical information

Download the BIOKIL. Passyfier Vents technical data sheet (PDF)