What is an Air Curtain?

Also known as air doors, air curtains are fan-powered machines that blow controlled air streams across doorways or other openings to develop an invisible air barrier. This allows them to separate two environments without limiting their access or visibility to people or cars.

They also help improve the indoor air quality of a building by controlling conditioned or heated air, controlling humidity, plus preventing pest and contaminant entry. There are different types of air curtains depending on your budget, purpose, and the location, size, and height of your doorway.

• Non-recirculating air curtains- These are the most popular type, and you can install them horizontally over your doorway. They direct sheets of air to the bottom and dispense them into the environment.
• Recirculating air curtains- These come with a receiving grille that absorbs and then recycles air sheets through a discharge grille. This allows them to have a denser air wall than non-recirculating air curtains.
• Heated air curtains- This release cold or warm air sheets that push the internal and temperature-controlled air of the building back inside. You can get them as non-recirculating or circulating.
• Unheated air curtains- These release air sheets that prevent pests and other air contaminants from entering the building. However, since they don’t have heating abilities, they don’t control indoor temperatures during winter.

While most air curtains are installed horizontally over the door, you can have yours installed vertically on the sides of the door.

How do air curtains work?

When turned on, air curtains suck in the air via the intake grille into the fan housing. Most intake grills come with filters to protect the fans, heat exchanger, and other electronic parts from dust and debris.

The fan then accelerates the air, which goes into a plenum. The plenum allows the air curtain to evenly distribute the air along the discharge nozzle’s full length, resulting in laminar airflow.

The curtains have airfoil-shaped vanes inside the nozzle to create uniform air streams with minimal turbulence. You can adjust the vanes to alter the air discharge angle for optimum performance.

The air from the nozzle forms a jet stream to the floor, and around 80% of the air goes back into the curtain, while approximately 20% is released into the environment.
If you have a very big discharge angle, the curtain will not stop enough wind from getting in near the floor, while a very small discharge angle means little horizontal force preventing significant wind from entering.

Where to use air curtains

• Grocery stores
• Restaurants
• Hospitals
• Warehouses
• Food processing plants
• Airports
• Schools
• Airports
• Malls
• Retail stores
• Drive-through windows

Benefits of air curtains

• They make every part of the room comfortable
• They improve food safety when installed near walk-in storage
• They boost your business’ reputation
• They improve employee productivity and satisfaction because of comfortable working environments
• They increase sales through the open-door effect
• They offer free and easier access to people using wheelchairs, strollers, or trolleys
• Maintain usable space near the doorway
• They are cost-effective because they reduce the amount of time you need to run your HVAC system
• Promote safety by keeping the floor free of things like water and ice