Air curtains FAQ: technology, benefits and applications
Find practical answers to common questions about air curtains: how they work, where they are used, how they can reduce energy losses and draughts, and what to consider when selecting, installing and maintaining the right system for your building.
Please choose a topic:
1. Basics and how air curtains work
What is the purpose of an air curtain?
An air curtain creates a powerful, invisible air stream across a door or industrial door opening. This air stream acts as a barrier between indoor and outdoor areas, reducing the ingress of cold or warm air, dust, insects and exhaust fumes without the need to close a physical door.
By reducing air exchange, an air curtain can reduce heating and cooling losses through open doors. This can also reduce the associated demand for heating or cooling energy.
For more details, please see our section on how air curtains work.
What is the difference between an ambient air curtain and a heated air curtain?
The main difference between an ambient air curtain and a heated air curtain is the temperature of the air discharged and the type of application they are designed for.
Ambient air curtains do not have a heat exchanger or heating element. They use the surrounding air and are often installed in industrial buildings to reduce the ingress of outdoor air at hall doors and to minimise draughts in working areas.
Heated air curtains discharge warm air. The indoor air drawn into the unit is heated either via a heat exchanger connected to the building’s heating system or by an electric heating element. This creates a more comfortable entrance area while maintaining effective separation between indoor and outdoor air.
If you are unsure which version is best suited to your building, please contact one of our consultants. They will be happy to help you find the right solution.
What are the advantages of a heated air curtain?
Air curtain systems can operate with ambient air, be connected to the building’s heating system, or be heated electrically. All versions can provide effective air separation when correctly selected and installed.
A heated air curtain improves comfort in the entrance area and helps create a welcoming environment for customers, visitors and employees. Passing through a warm air stream is generally perceived as more pleasant, especially in colder months.
Heated air curtains are suitable for a wide range of commercial and industrial buildings, including shops, restaurants, warehouses and entrance areas with regular foot traffic. If the indoor space is already sufficiently heated, the heating function can be switched off and the unit can continue to operate in ambient mode.
When does an electrically heated air curtain make sense?
An electrically heated air curtain is particularly suitable for retrofit projects where connecting the unit to the building’s heating system is not possible, difficult or disproportionately expensive.
It can be a practical solution for entrances where no heating pipework is available, where installation work needs to be kept to a minimum, or where a flexible, self-contained heating option is required.
2. Applications and benefits
Why are air curtains so common in shops?
Shops use air curtains for several important reasons.
Air curtains help reduce uncontrolled air exchange between indoor and outdoor areas. In winter, this limits heat loss; in summer, it helps keep warm outside air from entering the shop. This can reduce the load on heating and air conditioning systems.
They also improve customer comfort. By helping to maintain a stable indoor temperature, air curtains create a more pleasant shopping environment without the need to keep entrance doors closed.
Another advantage is architectural flexibility. Air curtains can be integrated discreetly into entrance areas and allow doors to remain open and inviting, supporting visibility, access and customer flow.
Air curtains can reduce air exchange at open entrances and help maintain a more stable indoor climate in smaller shops.
Even with large entrance façades, air curtain systems can be integrated almost invisibly into the existing architecture.
Do air curtains cool a room in summer?
Air curtains are not designed to cool a room by themselves. Instead, they help keep warm outdoor air from entering and conditioned indoor air from escaping through open doors.
By reducing the ingress of warm outdoor air and the loss of conditioned indoor air through open doors, an air curtain can reduce the cooling demand on the air conditioning system. This can help maintain a more stable and comfortable indoor temperature on hot days.
In some applications, air curtains can also be designed with cooling via chilled water or refrigerant. Please contact our experts if you would like to know whether this option is suitable for your building.
What is the difference between an air curtain and an air conditioning system?
Air curtains and air conditioning systems perform different functions.
An air curtain creates an invisible air stream across an open doorway. It helps separate indoor and outdoor air, reducing heat loss, draughts, dust, insects and warm air ingress.
An air conditioning system actively controls the indoor climate by cooling, heating or dehumidifying the air inside the room.
In short: an air curtain protects the doorway, while an air conditioning system conditions the room.
Air curtain vs overdoor heater: what is the difference?
When choosing an entrance climate solution, many building owners compare air curtains with overdoor heaters. Although both are often installed above doorways, they are designed for different purposes.
An overdoor heater primarily provides warmth near the entrance, whereas an air curtain is designed to reduce air exchange between indoor and outdoor areas. An air curtain is therefore suitable where air separation across an open doorway is required.
Air curtains
- Cover the full width of the doorway
- Use fans designed to project the air stream across the doorway
- Create a uniform air barrier across the entrance
- Help maintain indoor temperature and reduce energy loss
Overdoor heaters
- Are often narrower than the doorway
- Usually have less powerful fans
- Provide localised heating rather than an air barrier
- Are mainly suitable for smaller, low-traffic entrances
3. Energy efficiency and operating costs
Do air curtains save energy?
Correctly selected and installed air curtains can reduce energy losses through open doors by limiting the uncontrolled exchange of indoor and outdoor air.
In winter, this can reduce heat loss. In summer, it can reduce the ingress of warm outdoor air and the loss of conditioned indoor air. The actual reduction depends on factors such as door size, opening time, temperature difference, wind conditions and the design and operation of the air curtain.
Air curtains are particularly effective in commercial buildings with frequent door traffic, such as shops, restaurants, hotels, warehouses and industrial facilities.
How energy-efficient are air curtains?
Air curtains can reduce energy losses through open doors and industrial doors by limiting the uncontrolled exchange of indoor and outdoor air. This can reduce heat loss in winter and the ingress of warm outdoor air into air-conditioned buildings in summer.
The actual reduction depends on factors including door size, opening time, temperature difference, wind conditions and the design and operation of the air curtain.
A correctly sized Teddington air curtain can reduce energy loss through an open, unprotected doorway by up to 80%. You can use our efficiency calculator to estimate the potential savings for your specific door or industrial door situation.
Important: An incorrectly sized or installed air curtain can reduce or even eliminate the intended benefit and may result in unnecessary energy consumption. The system should therefore be designed and adjusted for the specific entrance situation.
Contact our experts to find the right solution for your entrance.
How long does a door need to be open for an air curtain to be economical?
An air curtain can be economical wherever doors are opened regularly or remain open for longer periods. This is especially true for high-traffic entrances in shops, restaurants, hotels and industrial buildings where doors are frequently used by customers, employees or suppliers.
Whether and from what opening duration an air curtain becomes economical depends on the individual door and building situation. Important factors include door size, opening time, temperature difference, wind conditions and energy costs. The more frequently or longer a door remains open, the greater the potential for reducing heating and cooling losses.
Use our online efficiency calculator to estimate how much energy you could save with an air curtain in your building.
Are air curtains sustainable and environmentally friendly?
Air curtains can help reduce the energy demand of a building. At open doors and industrial doors, they limit uncontrolled air exchange between indoor and outdoor areas and can therefore reduce heating or cooling losses.
Teddington air curtains with the CONVERGO® pressure chamber nozzle system provide an additional benefit: the precisely directed air stream requires a lower air volume for effective air separation than conventional air curtains. As a result, less air needs to be moved and, in heated systems, less air needs to be heated.
A lower demand for heating or cooling energy can – depending on the energy system used – also reduce the associated greenhouse gas emissions. The actual reduction depends on factors including the installation situation, system design and operation.
You can estimate the potential energy savings for your building using our efficiency calculator.
4. Installation and maintenance
How do you install an air curtain?
An air curtain is usually installed on the ceiling or wall above the door opening. The exact position is selected carefully to ensure that the air stream covers the entrance effectively.
After installation and electrical connection, the unit is tested to make sure it operates correctly and provides the required airflow across the doorway.
For best results, installation should be carried out by experienced specialists who can take account of the door dimensions, mounting position, air discharge direction and site conditions.
How much maintenance does an air curtain need?
Regular inspection and cleaning are important for maintaining the correct operation of an air curtain. The unit should be checked for dirt and dust, filters and fans cleaned as required, and functional checks carried out at appropriate intervals.
If you have any questions about installation or maintenance, please contact us. Our experts will be happy to help.
What factors should be considered when choosing the right air curtain?
Choosing the right air curtain system for your building depends on several factors. Each of these influences the effectiveness, comfort and energy efficiency of the system.
- Area of application: Consider where the air curtain will be installed, for example at an entrance door, roller shutter or cold room. The application influences the required size, type and performance of the system.
- Door size and installation height: The dimensions of the door are crucial. Wider and higher openings require the air curtain to be sized accordingly to provide the required airflow across the doorway.
- Climatic conditions: Local climate, outdoor temperatures and the wind situation at the entrance all influence system selection. In colder climates, a heated air curtain may be required, while in warmer regions an ambient air curtain may be more suitable.
- Air flow velocity: The air flow velocity is important for the effectiveness of the air curtain. It must be matched to the application and entrance situation to create an effective air barrier.
- Noise level: Noise can be important for user comfort, especially in sensitive areas such as offices, restaurants or hotels. In these applications, low-noise models should be considered.
Taking these factors into account allows the air curtain to be matched to the specific building and entrance situation. Our product finder helps you find the right air curtain for your requirements in just a few clicks. If you need help selecting the right system, please contact us. Our experts will be happy to advise you.
5. Comfort and health
Can air curtains contribute to employee wellbeing and reduce sickness absence?
Air curtains can help improve comfort for employees by reducing draughts at open doors and supporting a more stable indoor climate.
In entrance areas, warehouses, workshops and other buildings with frequent door traffic, cold draughts can be unpleasant and may affect workplace comfort. By helping to separate indoor and outdoor air, air curtains can make these areas more comfortable for employees, customers and visitors.
A more stable indoor climate can support employee wellbeing. However, air curtains should not be presented as a medical solution or as a guaranteed way to reduce sickness absence. Their main contribution is to improve comfort, reduce draughts and help maintain more consistent indoor conditions.
How loud are air curtains in operation?
Modern air curtains are designed to operate quietly and unobtrusively. The sound level depends on the model, air performance, installation situation and surrounding room acoustics.
In many applications, the sound level is comparable to normal background noise or a conversation. However, when selecting an air curtain, noise should always be considered in relation to the size of the entrance, the required air performance and the sensitivity of the area.
For better comparability of sound data, it is advisable to look for specifications in accordance with ISO 27327. This international standard is used by leading European air curtain manufacturers. The technical data for Teddington air curtain systems is provided in accordance with this standard and is regularly tested by the Institut für Luft- und Kältetechnik Dresden (ILK).
With the E-Series Silent, Teddington offers a particularly low-noise air curtain model for areas where a quiet environment is important, such as offices, restaurants, libraries and hotels.
6. Further considerations
Do air curtains run continuously or only when needed?
Whether an air curtain runs continuously or only when needed depends on the application, the entrance situation and the control concept.
In high-traffic areas such as shops, restaurants, hotels and office buildings, air curtains are often operated continuously during opening hours to maintain a stable air barrier against cold, heat, draughts and other external influences.
However, modern air curtains can also be controlled automatically. Depending on the system, they can be linked to door contacts, sensors or building controls so that they operate only when the door is open or when air separation is required. This allows operation to be adapted to the actual door-opening and usage situation.
In warehouses, production areas and industrial buildings, continuous operation may be useful if doors remain open for longer periods or if a stable indoor climate needs to be maintained. The operating mode should therefore be selected according to the building use, door-opening frequency and comfort requirements.
What are the disadvantages of an air curtain?
Air curtains offer many benefits, but there are also some points to consider before selecting a system.
- Initial cost: The purchase and installation cost of an air curtain can be relatively high, especially for large entrances, high-performance units or architecturally integrated solutions. Depending on the entrance situation, reduced energy losses can offset part or all of the investment over the operating life of the system. The potential can be assessed for the individual project using our efficiency calculator.
- Energy consumption: Air curtains require electricity to generate the air stream. It is therefore important to select an efficient unit and operate it appropriately. Teddington air curtains with the patented CONVERGO® pressure chamber nozzle system require a lower air volume than conventional air curtains with air guide vanes to provide effective air separation. As a result, less air needs to be moved and, in heated systems, less air needs to be heated. Use our online calculator to estimate your potential energy savings with a Teddington air curtain in just a few clicks.
-
Maintenance: Regular inspection and cleaning are important for maintaining the correct operation and separation performance of an air curtain. The unit should be checked for dirt and dust, filters and fans cleaned as required, and functional checks carried out at appropriate intervals.
To maintain consistently good separation performance, the filter of an air curtain should be cleaned at least twice a year, or more frequently depending on dust levels. Watch this short YouTube video to see how the filter is checked and cleaned.
The exact maintenance requirements depend on the installation conditions, operating hours and level of contamination. Regular maintenance also provides an opportunity to identify wear or other issues at an early stage. The P-Series is particularly easy to maintain thanks to its design.
- Noise: Some air curtains can generate noticeable noise during operation, particularly in quiet environments. If sound levels are important, for example in offices, hotels, restaurants or libraries, a low-noise model such as the Teddington E-Series Silent should be considered.
- Limited effectiveness in extreme conditions: In very strong winds, severe weather or unfavourable pressure conditions, the effectiveness of an air curtain may be reduced. In such cases, additional measures may be required to maintain comfort and separation performance. Our experts will be happy to advise you on suitable options for demanding entrance situations.
- Correct sizing and configuration required: The effectiveness of an air curtain depends significantly on correct sizing, installation position and adjustment. An undersized or incorrectly installed unit may not achieve the required air separation. The system should therefore be matched to the door dimensions, building and pressure conditions and the specific application.
Despite these potential limitations, a correctly selected, installed and adjusted air curtain can offer clear benefits in high-traffic areas where indoor comfort, reduced energy losses and protection from external influences are important.
Still have questions? Simply use the contact form below to get in touch with us. Our team will be happy to advise you personally, whether you need support with technical details or have specific project requirements.
How can we help with your project?
Tell us about your requirements using the contact form. Fields marked with * are required.
- Air discharge system: CONVERGO® pressure chamber nozzle system
- Air discharge range:
- Mounting position:
- Application:
- Shape:
- Heating options:
- Sound insulation:
- Unit length: Custom unit lengths available
- Fan type: AC