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.
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.
For cold rooms and freezers air curtains are the safest way to protect the energy losses without any physical barrier that can create accidents or collisions on the doorway. For example, when plastic strip curtains are used the view across the doorway is limited and people or vehicles accidents occur, with compensation consequences. Besides it prevents bothersome and potentially dangerous fogging, humidity and ice formation in the door entrance area.
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.
To select an air curtain the following factors should be kept in mind:
- The height of the installation measured from the discharge diffuser to the floor
- The width of the door
- The location of the building to determine the level of protection needed against weather conditions (temperature, humidity and wind)
- If the building has several doors in the same area, different or opposite façade
- If the building has several storeys connected by escalators/stairs
- Pressure differences between the inside and outside of the building
- Door characteristics: If always open, it opens automatically, it opens manually, revolving door, etc.
- Characteristics of the ventilation and air conditioning installation
- Voltage and electrical power availability
- Type of business, style and decoration of the premises
- Free hanging or recessed, horizontal or vertical installation, heated or unheated, etc.
Some installations with strong wind conditions may compromise
the air curtain due to: Severe wind, extreme temperature difference
indoor/outdoor, more than one door, different levels, big halls, high pressure
In those situations a higher performance model is recommended.
As explained, the air curtain selection depends on the installation situation. Here we show 4 different situations from the most favourable to the air curtain to the most unfavourable.
Revacco sales representatives with their extensive experience are at your disposal to help you choose the right air curtain for all applications.
Heat pump technology
Heat pump is a device that uses a small amount of energy to move heat from one location to another. This system is extremely efficient because it simply transfers heat, rather than burn fuel to create it.
It consists on a closed circuit through which a special fluid (refrigerant) flows. This fluid turns into a liquid or gaseous state according to temperature and pressure conditions.
The circuit is composed by: compressor, condenser, expansion valve and evaporator.
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).
An air curtain is a fan-powered device that creates an invisible air
barrier over the doorway to separate efficiently two different environments,
without limiting the access of the people or vehicles
The energy saving air screen reduces heating and cooling costs by up to 80% while protecting the internal climate and increasing people comfort.
It keeps the atmosphere clean from pest and insects, dust, airborne, pollution, smells, odours and stops draughts and cold or hot air entrance.
The functioning of an air curtain is based on a high velocity jet of air that covers all openings. Heated air curtains creates comfort by the jet of air on people as they cross the air screen and helps to maintain the temperature on the entrance.
Generally the air entering through the inlet grille, sometimes with filter functions, is compressed by internal fans and forced thought an air outlet, which is directed at the open doorway.
The filter protects the interior components (heat exchanger, fans, electronics, etc.) from dust and particles.
The fans of the air curtain can be direct or belt driven. The most frequently used types are centrifugal, axial and cross-flow.
Some air outlets and/or lamellas can be adjustable to increase the performance of the air curtain according to each situation.
Heated air curtains have a coil (electric, hot/chilled water, steam, indirect or direct gas, direct expansion, etc.) to heat or cool the jet. Heating is used to avoid people feeling a cold jet of air when crossing the doorway and also to heat the volume of air coming in at the entrance.
There are 3 possible directions of blow-out air streams:
Most air curtains are installed horizontally, across the top of the opening, and air is expelled from top to bottom of the door. Vertical air curtains can be installed in one or both sides of the door. Horizontal installation integrated on the floor is the most effective in thermodynamic terms and at the same time the most expensive one to install and problematic where public pedestrian traffic crosses the doorway for obvious reasons. So it's only used in some special industrial applications.
Types of air curtains: non-recirculating or recirculating. A non-recirculating unit discharges the air to the environment. Otherwise recirculating collect and return the air from the discharged air. Recirculating air curtains are more efficient but the majority of installations are non-recirculating due to lower costs.
We classify the air curtains advantages in 4 groups:
- 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 enviroment
- Reduces employee absenteeism
- Pest and insect control
- Barrier against airborne dust, pollution, fumes and bad odours
- Reduces the energy losses from the conditioned space
- Reduce central plant capacity (heating/cooling)
- Reduces the building running cost
- Reduces the CO2 emissions
- 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.
In conclusion, on open doorways it is highly recommended to use an air curtain because of the many benefits. For inquiries about Air Curtains, please contact Revacco Sales Office.
Our sales representatives are readily available to help with your Air Curtains inquiries. You can also contact Revacco directly if you have any questions or requests about our own made and foreign supplies.