Abstract: A damper, damper kit and method are for installing a damper in a duct defining a gas conduit. The damper kit includes a first aperture closing unit engageable with at least one conduit wall and configured to close a first aperture when engaged therewith and including a shaft receiving section opened in the gas conduit. The damper kit has a second aperture closing unit engageable with the at least one conduit wall and including a shaft receiving section opened in the gas conduit. The damper kit includes a damper having at least one shaft with a first section insertable in the shaft receiving section of the first aperture closing unit and a second section insertable in the shaft receiving section of the second aperture closing unit and extending past the at least one conduit wall through the second aperture closing unit.

Abstract: An air pressure measuring ventilation system, comprising: at least one duct; at least one motorized exhaust fan; and one or more air pressure sensors. The at least one motorized exhaust fan may draw air through the at least one duct. The one or more air pressure sensors may be placed on a side of the at least one duct such that an air pressure is measured as the air is drawn through the at least one duct, such that a plurality of air pressure measurements are generated. The one or more air pressure sensors may be substantially flush with an interior side of the at least one duct and do not obstruct the air as the air is drawn through the at least one duct.