Louver — Slatted Vent Panel Guide for Ventilation Use

A louver is a slatted vent or panel that allows air to pass while limiting rain, debris, or direct visibility.

What It Is

Louvers use fixed or adjustable blades set at an angle to manage airflow through doors, walls, attic openings, mechanical rooms, and equipment screens. The slats shield the opening while still allowing ventilation or pressure relief.

Types

Common forms include fixed wall louvers, operable louvers, door louvers, attic gable louvers, and HVAC transfer grilles that function like louvers. Materials include wood, aluminum, steel, vinyl, and molded composites.

Where It Is Used

Louvers are used in exterior walls, gable ends, mechanical room doors, closet doors, under-eave vents, and HVAC air transfer openings. They are especially common where airflow is needed without a fully open grille.

How to Identify One

A louver has angled slats rather than an open grill face or insect screen alone. If you can see a row of overlapping blades that direct air and shed water, it is a louvered assembly.

Replacement

Replacement is needed when the frame rots, slats break loose, the unit rusts, or airflow is no longer adequate for the space it serves. Sizing and weather details matter because a poor replacement can introduce water leakage or ventilation problems.