NOSE CONE PAX PASSAD 31

The shaft guard is installed in place of the backdraft damper when the fan is to be installed in a duct with natural draft, such as a gravity-based ventilation duct in the ceiling or a chimney. The shaft guard is suitable for the Pax Passad 31 fan from which the backdraft damper has been removed. The existing backdraft damper is removed using the shaft guard as a tool, and vice versa. The difference between the two is that the backdraft damper has vanes that close the duct when the fan is not running. The shaft guard is needed to support the fan shaft. The shaft guard is standard in Pax Passad 00 and 30 series fans, whereas the Passad 31 fan comes with a backdraft damper as standard. The backdraft damper must not be used in a naturally ventilated duct because it obstructs natural air exchange, which is detrimental to the structure and indoor air quality. This product description is an automated translation of the original Finnish description.