Abstract: A low cost air damper that provides a good seal with low torque requirements. Blade seals of square cross sectional configuration are provided on each damper blade so that the blade seals engage adjacent blades before the blades are fully closed. L-shaped side seals and multiple discs that receive the ends of the blades serve collectively to seal between sides of the damper frame and the blades when the blades are closed even when the blades are not cut precisely. One edge of the L-shaped side seals engages and seals against the discs and the other edge of the side seals laps over and seals against a flat side of the blades and against the square blade seals. A low friction coating is applied to the side seals to further reduce friction.

Abstract: An air diffuser comprising a base and first, second, third and fourth side walls extending from the base to form a hollow shell. At least one of the side walls includes a plurality of bores therein forming multiple discharge tubes. The base and side walls form a plenum into which conditioned, pressurized air is supplied. The conditioned air is discharged from the plenum through the tubes in columns. Screws or other fastening devices may be used to secure the hollow shell to a surface. The multiple discharge tubes are each spaced from the surface and have longitudinal axes oriented in angular relation to the surface for entraining ambient air from above and below each column of air being discharged for mixing of ambient air with each column of the discharged conditioned air.