bath fans, exhaust to exterior

[Jeff Eastman]

..........

[John Arnold]

Jeff - 2006 IRC says exhaust fan is required (and must vent directly to outside) when a window of at least 3 square feet, half of which must be openable, is not present. Section R303.3
Actually, what it says is that the window must be provided unless there is an exhaust fan. Same difference.

[Dave Hahn]

Yeah, R303.3

[Tim Moreira]

Jeff,

03 IRC: Bold is mine

303.3 Bathrooms.
Bathrooms, water closet compartments and other similar rooms shall be provided with aggregate glazing area in windows of not less than 3 square feet (0.279 m2), one-half of which must be openable.

Exception: The glazed areas shall not be required where artificial light and a mechanical ventilation system are provided. The minimum ventilation rates shall be 50 cfm (23.6 L/s) for intermittent ventilation or 20 cfm (9.4 L/s) for continuous ventilation. Ventilation air from the space shall be exhausted directly to the outside.