Air Curtains

Tell me what is an Air Curtain or Air Door?

An air curtain, also known as an air door, air screen or air barrier uses a controlled stream of air aimed across and down from an opening to create an air seal. This seal separates two environments (one from the other) while allowing a smooth, unhindered flow of traffic and unobstructed clear vision through the given opening. Because air curtains help to contain heated or conditioned air, they provide a considerable energy savings, while also providing personal comfort when applied in an industrial or commercial setting. Air curtains also help to stop the infiltration of flying insects, light debris, dust and other small particulates.

There are generally two types of Air Curtains:

Non-recirculating Air Curtains

the non-recirculating type of air curtain is more widely used than the recirculating type because they are easier and less costly to install and also offer a lower maintenance cost over time.

Recirculating Air Curtains

The recirculating air curtain is mainly used in places where consistent foot traffic is present, such as supermarkets, restaurants and general store entrances. The recirculating air curtain is also know as Air Entrance Systems, and are built into the entrance, usually at the time the entrance is being constructed. They produce air from a discharge grille on one side of the door opening, collect it through a receiving grille on the opposite side and return it through duct work to the discharge grille once again. The non-obtrusive wide stream of low-velocity air created by the recirculating air curtain is more desirable for separating two environments.

Why do I need an Air Curtain for my business or establishment? Here are a few reasons why:

Energy savings through control of air transfer (keeping heated or cooled air in your building or facility)
Energy savings due to shorter run times than that of an air handler or mechanical compressor
Helps to maintain comfort for both the employee and the customer
Reduce flying insect, dust and other small particulate infiltration into your establishment
Unhindered traffic flow (no constant opening and closing of actual doors)
Unobstructed visibility across a threshold
Increase productivity due to stable temperatures and other environmental factors
Helps to maintain the usable space around doors and doorways
Reduces or entirely eliminates ice and fog in cold storage areas

Tell me how the Air Curtain works:

When turned on, air is pulled into the unit through the intake, it then enters the fan housing and finally is accelerated by the fan. This fast moving air goes into a plenum (an enclosed chamber where a treated substance collects for distribution, as heated or conditioned air through a ventilation system), which allows for an even distribution of air along the full length of the air curtains' discharge nozzle. Aerofoil shaped vanes in the nozzle create a uniform air stream with minimal turbulence.

For the air curtain to perform efficiently, the angle of the discharge nozzle must be set correctly. An air curtain nozzle should be adjustable to aim inward or outward up to 20 degrees from the opening in either direction. The air discharged through the nozzle creates a laser like jet stream to the floor. Approximately 80% of the air returns to the intake side of the air curtain, and 20% goes in the opposite direction.

Non-recirculating air curtains can be mounted either horizontally above the door, or vertically on one side or both sides of the door, depending on the space available and the height, width and physical characteristics of the doorway or opening. The horizontal mounting of and air curtain(s) above the door minimizes the likelihood  of damaging the air curtain(s). Protective measures should be taken if the air curtain(s) are mounted vertically.

Proper sizing, power rating and other features needed for a particular air curtain application should be selected according to the following considerations:

The physical dimensions of the opening, including height, width and space available for installation of an air curtain or air door.
The type of door being used (typical swing door, bay door, slider door etc..).
The type or purpose of opening (customer entry, service entry, dock door, etc..).
The climate inside the building, also would supplemental heat at the door be appreciated by the buildings' occupants?
The prevailing winds and exterior climate and or temperatures on outside openings.
Is there the existence of any drafts due to atmospheric pressure differences at the opening?

Do I need to do any maintenance on my Air Curtain once it has been installed and in use?

Maintenance of an air curtain, air door should be scheduled at least 4 times per year to ensure the air curtain performs properly. This maintenance will also help extend the life of the air curtain. If the area where the air door has been installed is dusty, dirty, or greasy, maintenance me be required on a more regular basis.