Air Curtain

Overview

An air curtain hangs above a doorway and blows a fast, flat sheet of air straight down across the opening. That moving stream resists the natural exchange of air between two spaces, so a shop can keep its conditioned air inside while the door stays open for customers, and a cold store can hold temperature without a physical door. Because nothing blocks the opening, people, carts, and forklifts pass through freely.

The whole machine lives in a long Cabinet Housing mounted horizontally above the door. Room air is drawn in through the Intake & Filter on the top or back, accelerated by the fan, and thrown down through the Discharge Nozzle. A wall switch or the Control Module board sets fan speed, and a door contact can start the unit only when the door opens. Heated models add an element bank so the descending air also warms the entrance.

How it works

The heart of the unit is the Cross-Flow Blower: a long cross-flow fan barrel spun by the Induction Motor Core. Unlike a propeller fan, a cross-flow rotor takes in air along its entire length and discharges it as a uniform line, which is exactly what a door-wide air stream needs. The barrel rides on bearings at each end, and an internal scroll shapes the flow before it reaches the slot.

At the outlet, the Discharge Nozzle narrows the path so the air leaves fast and coherent, and adjustable vanes aim the jet slightly toward the outside to counter wind and stack pressure. When the jet reaches the floor it splits, most of it rolling back up on the conditioned side, which is what makes the barrier hold rather than simply dumping air outdoors.

On heated units the Electric Heater Bank sits in the discharge path. Finned resistive elements warm the passing air, a high-limit thermostat and a Thermal Fuse cut power if airflow is lost, and a contactor switches the load. The Control Module coordinates fan and heat: it runs the fan a moment before energizing the elements and purges heat after shutdown so the elements never bake in still air. A Door Limit Switch lets the unit idle until someone opens the door, saving energy. The cabinet drops from the wall on the Mounting Bracket Set brackets.