Positive Input Ventilation (PIV) is a mechanical ventilation system that introduces fresh air into a building, typically from a unit installed in the loft space. The system works by creating a positive pressure inside the property, which forces stale air out through gaps and cracks in the building envelope. This method helps to reduce humidity levels and remove airborne contaminants.
PIV systems are designed to combat issues such as condensation and mould growth, which are common in poorly ventilated spaces. By continuously supplying fresh air, PIV systems help maintain a healthier indoor environment. The fresh air introduced is often filtered to improve air quality, and the system can be adjusted to control the flow rate according to the specific needs of the dwelling.
In a typical UK home suffering from damp and mould, a PIV unit can be installed in the loft. Once operational, the unit draws in fresh air from outside, which is then filtered and distributed throughout the house. As the fresh air enters, it displaces stale air, which escapes through small openings around windows and doors. This process not only reduces humidity but also improves overall air quality, making it particularly beneficial in older homes that may lack adequate ventilation.
PIV systems have gained popularity in both domestic and commercial environments due to increasing awareness of indoor air quality issues. For instance, schools and offices are now incorporating PIV systems to ensure a constant supply of fresh air, thereby enhancing the comfort and health of occupants. In residential retrofits, PIV can be an effective solution for homes that have been sealed for energy efficiency, helping to balance airtightness with necessary ventilation.