Gilberts louvres for natural ventilation
The Mistrale 75 series of louvres for natural ventilation from Gilberts of Blackpool is claimed to offer some of the lowest air-leakage rates and U values of its kind. It is also very slim — just 200 mm thick— and is designed for ease of integration into the external envelope of the building.
These louvres achieve accurate and stable airflow, with air leakage as low as 5 m3/h/m2. The air leakage exceeds current and known future requirements — regulations currently demand air leakage of ≤10 m3/h/m2, and this is predicted to be lowered to ≤7 m3/h/m2.
The U-value of these louvres is as low as 0.93 W/m2K — comparable to a double-glazed window.
All Mistrale 75 units can be Class A weather-rated, whether using 50 or 70 mm-pitch external louvres.