Stationary-blade louvers provide a path through an exterior wall for air exchange in and out of a building. They can be installed independently for smaller openings or connected in a grid pattern to cover larger areas. They provide water intrusion protection but do not have a drainage system to deal with rain that falls onto the blades. Any rainfall that hits them will be carried downwards by gravity.

Stationary-blade adjustable-width louvers expand or contract in width to fit a variety of openings. They feature a flanged frame and blades that nest inside each other and slide. This allows the louver to adjust its width to fit various openings in an exterior wall. They provide water intrusion protection but do not have a drainage system to deal with rain that falls onto the blades. Any rainfall that hits them will be carried downwards by gravity.

Drainable stationary-blade louvers have integrated drain channels on each blade, channeling rainwater toward the side of the louver and down toward the frame jamb. This prevents the dripping water from being caught in the airstream and reduces water intrusion through air intake openings.

Drainable adjustable-blade louvers open and close to regulate a structure's intake and exhaust airflow. They can either be adjusted manually or remotely with an electric motor. This eliminates the need for additional parts like an adjustable damper and reduces the overall footprint of the HVAC equipment.