Application. AirM R1 top- and AirM R2 side-flow mixing sections for recirculation systems, with back-up fan or to organise the air intake or exhaust in the desired direction. Design and materials. Service panels on top for AirM R1 or on the side for AirM R2 allow connection of standard dampers and flexible inserts of the appropriate size. The operating temperature range of the flowing air is -40°C to +70°C.