Positive Input Ventilation (PIV)

The average family will produce around 15l of moisture per day from breathing (respiration), cooking, bathing, dishwashing, and drying clothes. Failure to remove this moisture can result in a build-up of damp and mould. This can result in health issues in particular for those with respiratory issues, asthma or allergies. Xpelair Everdri is a whole house ventilation control system for houses with a loft space. The unit gently ventilates the home from a central position on the landing in a house or the central hallway in a bungalow to transform a stagnant and stale atmosphere into a fresh, healthy and condensation-free environment.

How does PIV work

PIV works by continually diluting, displacing, and replacing indoor air with filtered, low moisture content external air from either the loft or an external source. This air is delivered to a central point in a property and, in turn, each room off this central point benefits. Everdri is adjustable, so the amount of ventilation they provide can be adjusted to the amount of moisture being produced or the size of the home.   Everdri is a loft-mounted solution. Whilst it can be a very effective method of ensuring a continuous air exchange within a property, the surveyor and the occupant must be made aware of its limitations and must acknowledge that in many instances it must be considered as part of a ventilation system and not used in isolation.  In the vast majority of existing homes, the air supplied by a PIV unit will exit via the myriad of small gaps in the building structure. Background ventilators (e.g. trickle vents in windows) will only be required in extraordinarily airtight homes. If in doubt about this, please seek specialist advice.  

Xpelair Everdri is a preferred solution under the following circumstances :

  • A full renovation is not required
  • A wholehouse ventilation system is not preferred
Image of Positive Input Ventilation product
Image of Positive Input Ventilation product
Image of Positive Input Ventilation product

Everdri XEL / XEL:H

Positive input ventilation unit