Are there any situations that will cause an Air Curtain not to
perform properly? 
Yes, there are a few situations that will cause an Air Curtain not to perform as
desired. The main reason is if there is an excessive negative pressure in the building. No
Air Curtain can withstand excessive negative pressure. Some make up air has to be provided
in these cases, in addition to an Air Curtain. The other situations arise from faulty
installation of the Air Curtain. The Air Curtain will not perform properly if it is
drawing outside air, or if it is not adjusted properly.
Can the Air Curtains be Mounted Outside as well as Inside?
Special Air Curtains can be made so that they can be mounted outside and use inside
air. (Please consult the factory when these are needed). The equipment can be mounted on
either side of the door, but for best performance, the air that passes through the Air
Curtain should come from the inside. The reason being the air stream is deflected to the
inside. Air taken from the inside is heated, the outside air is cold. The purpose of the
Air Curtain is to prevent cold air from entering, if you are putting cold air through the
Air Curtain, you are defeating the purpose and the Air Curtain will not perform as well as
it could.
What Type of Maintenance Does an Air Curtain Require?
NONE: (Note: With a special unit where belt drives are used the belts should be checked
every 2-5 years, depending on the number of starts that the unit has to do. In normal
applications the fans are self cleaning and should not require any maintenance for at
least 10 years. The exception is the belt drives. For severe use these may have to be
re-greased every 2-10 years. (More bearings are damaged from over greasing than not
enough!) If we supply the magnetic starters, these are of a long life with energy
efficient coils, these may require new contact points after some 100,000 operations. In
normal life, with some 1000 starts per year, this means a practically indefinite life.
Can an Air Curtain that is Smaller than the Door Operate
Efficiently?
Any Air Curtain that does not cover the entire door will not operate efficiently. In
order for the Air Curtain to prevent cold air or insects from entering it must cover the
entire area of the door opening.
How Far Above the Door Level Should the Air Curtain be Mounted?
An Air Curtain should be mounted just above the door jamb. If there is an obstruction
that prevents the Air Curtain from being mounted just above the door the Air Curtain has
to be moved out 1" for every 3" that the unit is mounted above the door. This is
so that the air stream will clear the door jamb and no turbulence is created.
How Far Away From the Wall can an Air Curtain be Mounted?
There is really no limit. However, side panels have to be installed so that they,
together with the Air Curtain, will form a vestibule. If you are uncertain, or have any
questions, please contact the factory. We can usually,
without charge, provide you with a design or, for a nominal charge, fabricate the brackets
and panels required.
On an Overhead Installation, What Happens to
the Air When it Hits the Floor?
As the air, both from the Air Curtain and the entrained air from the inside and
outside, hits the floor it will divide and send some air outside, and some air inside. If
the Air Curtain air was laminar at the nozzle, and this is important for proper operation,
then the majority of the air that goes outside is from the outside entrainment. This is
why our Air Curtains are very carefully designed. Particularly at the nozzle and at the
flow diverters (these are the connection pieces between the fans and the nozzle).
What Happens When a Forklift or Other
Vehicle Goes Through the Air Curtain Airflow?
The Air Curtain will still effectively seal the doorway, as the air stream goes around
the vehicle and seals the opening. The only exception is when an Air Curtain is mounted
vertically on one side only. The opposite side is not covered completely for the short
time that the vehicle is in the actual doorway.
Does an Air Curtain Improve the Circulation
in a Building?
Yes, an Air Curtain improves the circulation and destratifies a building. Our Air
Curtains are specifically designed to even enhance this, as they have the air intake from
the top of the unit. For very high buildings, it is advantageous to have some type of duct
work 6' below the ceiling, and allow the Air Curtain to draw from this warm air and push
it down to the floor level, where it is needed. In some instances it may be beneficial to
operate the Air Curtain all the time even though the doors may not be open. Our Air
Curtains are designed to withstand this, as they are designed to be able to operate
continuously.
Why Do Air Curtains Have Directional Vanes?
The airstream has to be angled towards the draft, usually 15-20°, for optimum
performance. This is how they are set at the factory. For special applications, for
example ovens or fly and insect control, this setting may have to be changed.
How Long Does it Take to Mechanically Install an
Air Curtain?
It obviously varies with different types of units and the different circumstances. On
average it takes 2-3 hours for the first one and 1-2 hours for the second one. This is
assuming that there are two workers installing the unit and a fork-lift or some other
means of lifting the unit is available.
If the Air that Leaves the Nozzle Doesn't Have
Much Velocity, What Might the Problem be?
The most probable cause is that the fans are rotating backwards. When this happens the
unit will still blow air but only a small amount. The way to fix this is to rotate any two
wires. The fans will then rotate the right way. Another cause might be that the units are
wired for the wrong voltage. If this is the case contact an electrician or the factory for help.
Is the Voltage Important when Ordering?
Yes, the voltage is very important when ordering. Without knowing the voltage needed
the wiring cannot be done and the proper motors will not be installed. Unless we know the
voltage that will be used we cannot build the units.
What is an Automatic Door Switch?
An automatic door switch is a switch that is mounted on the wall in such a fashion that
it closes an electrical circuit when the door starts to open. By doing this the Air
Curtain will start automatically. These switches are almost always used.
Do Air Curtains Meet OSHA
Requirements?
All Air Curtains we ship meet or exceed the OSHA requirements. The sound levels for
even the most powerful units are some 10 dbA below the allowed limits (90 dbA for 8 hours
exposure).
What is the Design Criteria for the Miniveil
Air Curtain?
