Why Do Mars Air Curtains Have Adjustable Louvers At The Air Intake?
Adjustable louvers are used to obtain optimum operating efficiency. When used over refrigeration doors, the louvers
can be adjusted to regulate the velocity and volume of air at the air outlet. This is important in order to form an air
barrier and balance the cold air inside the refrigerated box with the warm outside air. The louvers should be set so
the air barely hits the floor. The colder the air, the stronger and stiffer the barrier should be. When used as a barrier
to insects, louvers should be set at the maximum open position for full volume of air.
When Adjustable Velocity Control Louvers Are Completely Closed, Will The Motor Be Starved For Air And
Therefore Overload?
No, on the contrary, the motor will be working under a lighter load. When the louvers are closed, there is less air to
load the fan blades, thus allowing them to operate "free wheeling". The amperage draw of the motor drops
significantly.
Why Do Mars Air Curtains Have Adjustable Air Directional Vanes At The Air Outlet?
The air directional vanes in the discharge nozzle can be positioned inward or outward. This design feature provides
the capability to compensate for drafts, wind loads, and necessary adjustments to effectively repel flying insects,
dust, fumes, odors, and other wind borne contaminants. If the air curtain is mounted internally in a building for
environmental separation (i.e. separating a manufacturing area from a clean work area) or over a refrigerated room
door for temperature control, the directional vanes should be pointed straight down.
What Happens To The Air When It Hits The Ground?
As the air reaches the floor, it will divide, sending the air inward and outward simultaneously and causing a draft
both ways at the floor line. When using an air curtain for insect and dust control, the directional vanes in the air
outlet nozzle should be directed outward not only to repel the insects and dust but to also allow the least amount of
air to come inward when hitting the floor. If mounted on the outside of the doorway and used for the purpose of
holding in air conditioning when the door is open, the directional vanes should be slanted slightly outward. Mounted
on the inside of a cooler, the vanes should be turned slightly into the refrigerated room. It is important to remember
that when an air curtain is used for refrigeration or climate control, it is absolutely necessary to adjust the velocity
control so the air stream gently hits the floor with the least amount of vacuum reaction, thus pulling the air out of the
protected room and defeating the intended function of the air curtain and causes icing on the floor.