Air Curtain FAQ & Troubleshooting Guide


Mounting & Installation

How Long Does It Take To Install A Mars Air Curtain?

The average time required to install a unit is two hours. After the second or third installation, the time can usually be cut to one hour.

Do Mars Air Curtains Require A Cover When Mounted Outside?

No, they are not normally required as their design protects them from inclement weather. Weatherproof covers may be recommended when the units are exposed to harsh environments or excessive moisture. All unheated units are ETL/UL listed for outdoor use.

Is There Any Difference In The Sound Level If A Mars Air Curtain Is Installed Outside Or Inside?

Yes, if the level of sound is a problem mount the air curtain outside and the sound will be reduced.

How Far Above The Doorway Header Should The Air Curtain Be Mounted?

Mount air curtain ½” to 2” above the door opening whenever possible. The closer to the top of the door opening, the more effective the air curtain will be. Extended mounting brackets are available in various lengths so the air curtain can be mounted to clear an obstruction. If the unit is mounted higher, move it 3/8’’ away from the wall for every 1’’ it is moved above the door.

If There Is An Obstruction Over The Doorway, How Far Away From The Wall Can The Air Curtain Be Installed And Still Function Effectively?

Not more than 8” for refrigeration and 14” for insects. To seal off the ends, 12” to 18” panels made of sheet metal, plastic strips, or plywood can be installed on each side of the door opening to improve the efficiency of the air curtain. Sometimes the Mars Air Curtain outlet nozzle may be installed between the obstruction and the wall. Precaution is necessary to prevent the obstruction from deflecting the flow of air.

What Are The Normal Heights That An Electric Heated Mars Air Curtain Can Be Mounted?

Electric heated air curtains with ½ HP motors are normally used over customer entrance doorways in restaurants, supermarkets, department stores, personnel entrances, etc. and installed no more than 8’ above the floor. The colder the climate the higher the kW heater should be selected. If specifying electric heated models for use over warehouse doorways, use either HV or EP models. Higher kWs should be used in this case. Most electric heated models are supplied with motor control panels and wall mounted thermostats for ON/OFF/Fan Only control.

Operation & Performance

Are There Any Situations That Could Cause Air Curtains To Operate Poorly Or Not At All?

Yes. There are three applications to be avoided:

  1. Air curtains will not perform satisfactorily if there is an exhaust fan in operation causing a negative pressure within the building. The curtain of air will be strongest near the nozzle and weakest at the floor. Since air entering the building always seeks the least line of resistance, it will flow into the building a few feet from the floor at the door opening.
  2. A wind tunnel effect will prevent air curtains from operating properly. A wind tunnel effect occurs when there are two open doors, one on each side of the building.
  3. If an air curtain is mounted on the outside of a building to prevent the entrance of cold air, it will not perform properly. If mounted outside, cold air coming down will hit the floor, bringing cold air into the building. It must be mounted on the inside of a heated room.
Should The Customer Use A Thermal Overload Protection Switch In The Electrical Circuit?

Not necessarily. All motors used in Mars Air Curtains are equipped with an automatic thermal overload switch in the windings of the motor for protection against burnout. If, for any reason, the motor is overheating, the motor will automatically stop.
Possible causes for overheating are:

  1. Voltage or Phase:
    • Wrong voltage being fed to the motor.
    • Too low a voltage.
    • Phases unbalanced in three phase motors.
  2. Excessive vibration in fans caused by debris caught in the vanes.
  3. Motor dirty- Air cannot get to motor housing for proper cooling.
  4. Wiring hookup not properly followed, or the wire is too light a gauge from electrical panel to air curtain.
Are Variable Speed Motors Required On Air Curtains?

The ability to adjust the outlet airflow is highly desirable; this significantly aids in the air curtain’s performance by allowing compensation for varying field conditions. Most Mars Air Curtains boast this feature provided through the adjustable air intake louver. Some models feature variable or multi-fixed speed motors while others include internal volume dampers in the air curtain’s discharge nozzle or a combination of the above. NSF certified models do not have any variable speed options. Please note, due to NSF regulations consult factory for specific model offerings.

If A Warehouse Or Commercial Building Is Heated, What Are The Advantages Of Installing An Air Curtain?

Heat rises and tends to stratify. The air curtain will cause the air to circulate, eliminating the stratification; this helps to reduce heating costs. The directing of a space heater toward the air curtain intake, if practical, will assist this action and minimize any cold drafts by bringing the warm air down to floor level with sufficient velocity and at the same time will prevent cold air from entering the building, thus saving on energy bills.