Air louvers, like window louvers, are essentially shutters with horizontal slats that are angled to admit air while keeping out dust, dirt, and other particles.
The first louvers were lantern-like wooden constructions that were fitted on top of roof holes in large kitchens. As they do today, early louvers allowed ventilation while keeping out rain and snow.
Modern ventilation louvers are made of aluminum, metal, or glass and can usually be opened or closed with a metal lever, pulleys, or motorized operators. They have a variety of uses in architecture, infrastructure, and transportation.
Uses of Air Louvers and Dampers
Louvers have a variety of uses. These include:
- A type of flood opening in modern infrastructure. They are designed to allow floodwater to enter and leave a building, equalizing hydrostatic pressure and mitigating structural damage.
- A means of thermal control on spacecraft.
- An accessory for certain cars.
- A means of improving indoor daylighting, natural ventilation and temperature control.
In HVAC Ventilation
In modern HVAC ventilation, louvers are most often used to reduce temperature build-up inside the roof cavity during summer months and to reduce condensation, which can cause wood rot, mold, and other damage. The higher the louvers are placed, the more effective they are. Proper roof venting is critical to good construction practices and maintenance, because if installed improperly, or if the wrong type of louver is used, limited airflow will be provided under the roof deck, resulting in “hot spots”.