Aircon Air Curtain
Air Curtain reduces penetration of insects and unconditioned air into a conditioned space by forcing an airstream over the entire entrance. The air stream layer moves with a velocity and angle such that any air that tries to penetrate the curtain is entrained. Air curtain effectiveness in preventing infiltration through an entrance generally ranges from 60 to 80%. we at Cosyst Devices offer high quality and durable air curtains to all over India, we have our own manufacturing unit with offices in Bangalore & Mumbai.
Contact us to know about Air Curtain product capabilities, Installation services. we offer cost-effective air curtains for industrial and commercial use. Get High-performance air curtains with up to 70% power saving which maintains the hygiene in your work area and keeps the dust and flies away and maintains the ac temperature.
Uses
Architectural Air Curtains
Air doors are often used where doors are required to stay open for operational purposes, such as at loading docks and vehicle entrances. They can be used to help keep flying insects out by creating forceful turbulence, or help keep out outside air, thus reducing infiltration through the opening. Cold drafts can be avoided by mixing in warm air heated by the air door. Heated air doors are commonly used when supplemental heat is needed for a space, and to reduce the wind chill factor inside the opening, in colder climates.
Further applications include customer entryways, airplane hangars, cargo doors, drive through windows, restaurant doors, or shipping receiving doors. Non-heated air curtains are often used in conjunction with cold storage and refrigerated rooms.
Air doors can be equipped with or without heaters to heat the air. The fan must be powerful enough to generate a jet of air that can reach the floor. There are some studies in the scientific literature that present analytical methods to predict the sealing efficiency obtained with an air curtains.
EFFECTIVENESS
Airflow through a door depends on wind forces, temperature differences (convection), and pressure differences. Air doors work best when the pressure differential between the inside and outside of the building is as close to neutral as possible. Negative pressures, extreme temperature differences, elevators in close proximity, or extreme humidity can reduce the effectiveness of air doors.
The most effective air door for containing conditioned air inside a building with an open door will have a high face velocity at the opening, generated by top-down flow, and air recovery by a recirculating air plenum and duct return to the source fans. This configuration is feasible for new construction, but difficult to implement in existing buildings. The air door is most effective with low exterior wind velocity; at higher wind velocities, the rate of air mixing increases and the outside air portion of the total face flow increases. Under ideal conditions of zero wind, the effectiveness of the air door is at its maximum, but in windy locations air doors cannot create a perfect seal, but are often used to reduce the amount of infiltration from an opening.
For industrial conditions, high face velocities are acceptable. For commercial applications like store entrances, user comfort dictates low face velocities, which reduce effectiveness of separation of exterior air from interior air.
Energy savings
Air curtains consume electrical energy during their operation, but can be used for net energy savings by reducing the heat transfer (via mass transfer when air mixes across the threshold) between two spaces. However, a closed and well-sealed physical door is much more effective in reducing energy loss. Both technologies are often utilized in tandem; when the solid door is opened the air curtain turns on, minimizing air exchange between inside and outside.
An air curtain may pay for itself in a few years by reducing the load on the building's heating or air conditioning system. Usually, there is a mechanism, such as a door switch, to turn the unit on and off as the door opens and closes, so the air curtain operates only while the door is open.
Air curtains: Technology
It is known that on open doorways with two adjacent areas in different conditions the air is interchanged between them because the laws of physics tend to equalize the temperature and pressure difference between both sides.
Basically air transfer on doorways happens due to these 3 factors:
- Temperature difference: is the natural convection effect that creates an air transfer between two areas with temperature difference. Warm air will escape through the top of the doorway and being replaced by cold air coming in at the bottom. As bigger temperature difference bigger air infiltrations and energy losses
- Pressure difference: it is recommended to equilibrate the pressure difference as much as possible because it affects the air curtain performance. But in some installations like clean zones a little pressure difference helps to prevent the particles entering from outside
- Wind, stack effect and draughts: by modifying the air jet strength and the outlet discharge angle, the air curtain can work against forced air movements like wind or draughts. But if the velocity of the incoming air is excessive the air curtain will become less efficient
Advantages and benefits of air curtains
We classify the air curtains advantages in 4 groups:Commercial profitability
- Sales increase due to the “open door effect”. It is known that when doors are open, people affluence increases substantially
- Doors open is an invitation for customers
- Doorway acts as a shop window and allow people to see the inside of the shop
- Free access for disabled people (wheelchair) or people using baby strollers, trolleys, umbrellas, etc.
- Help to control uncomfortable sensations of draughts
- Increases available usable space on entrances
- Increases customers and staff comfort
Hygienic and healthy atmosphere
- Helps maintain adequate environment
- Reduces employee absenteeism
- Pest and insect control
- Barrier against airborne dust, pollution, fumes and bad odors
Energy saving
- Reduces the energy losses from the conditioned space
- Reduce central plant capacity (heating/cooling)
- Reduces the building running cost
- Reduces the CO2 emissions
Increased safety
- Increase visibility and avoid collisions because there isn’t a physical obstruction
- In cold rooms reduces misting, dry out the doorway and prevents ice forming on floors
- Easy evacuation through the exit doorway in case of fire or emergency
- Act as a barrier against fire smoke (special application)
To achieve those advantages it is absolutely necessary to select the right air curtain.
Air curtain with fixed lamellas less efficient (1)
Air curtain with oriented lamellas more efficient (2)
If we select a wrong unit the air jet won’t reach the floor and the separation of two adjacent areas will disappear. Then all heated/cooled air will cross the doorway and we will loose energy and all other advantages.
Some people only care about the air curtain price and select a less performance or inadequate air curtain, following sometimes other seller recommendations. Being confident you should always compare the characteristics of the air curtain, especially the kind of fans used and the air volume.
At the end if we calculate the amount of money of the air curtain and the energy savings we will achieve that selecting the wrong unit can be more expensive and moreover the end client won’t be satisfied.
In conclusion, on open doorways it is highly recommended to use an air curtain because of the many benefits.
Door climate protection
First and foremost air curtains are designed to prevent a climate area (heated or cooled) from the influx of outside air through an open doorway.
The air curtains reduce energy costs by keeping heated or cooled air in the internal building atmosphere.
Efficient air curtains will save up to 80% energy looses across a doorway compared with a door without air curtain.
During the winter an air curtain creates a barrier that keeps out the cold air while in the summer the air stream keeps out the hot air from outside.
Bearing in mind the energy saved, the average payback time for an air curtain is between 2 and 5 years depending on usage and climate conditions.
Pest and flying insect control
Insect air curtains are commonly used, when necessary, to stop insects from entering a buildings like food processing plants, bakeries, restaurants, hospitals, etc. Bugs in flight approaching will be stopped by a barrier of air too powerful to penetrate.
Air curtain stops flying insects entrance from the outside
You need to select the correct air curtain for insect repellent applications. A very powerful air jet along the all doorway is needed (stronger than standard applications).
Cold storage
Due to big temperature differences, it is highly recommended to install air curtains to reduce the energy losses when the door is open. The higher the temperature differences between inside/outside, then higher are the energy losses when a door is unprotected.
So the payback period of the air curtain is very short and then the energy/money saving is very high.
Not only we will save money avoiding air transfer through the door but also will keep the frozen goods in perfect condition and help to reduce defrost costs of the cold room.
Dust, pollution and airborne control. Clean rooms.
Always installed in the clean side of the doorway, air curtains act as a barrier against dust, particles and humidity.
Other applications
Drive-thru windows, separate smoking from non-smoking areas, industrial ovens, refrigerated display cabinets, etc.
