Technical Booklet K Ventilation·Page 48·3.22
Extract fans - manual or automatic control
Extract fans in rooms can be controlled manually or automatically. For internal rooms with no openable window, extract fans must have at least 15 minutes overrun unless controlled by a humidistat.
Extract fans can be controlled either manually or automatically. For a room with no openable window (i.e. an internal room), the extract should have an overrun of at least 15 minutes, except where it is controlled by a humidistat. For PSV, the ventilation can be controlled either manually and/or automatically by a sensor or controller.
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