Air curtains for a sustainable indoor climate

An air curtain is a device with a fan that blows air out of a nozzle to create an “invisible door” between two temperature zones, such as between indoors and outdoors. This helps to maintain the desired temperature indoors, resulting in energy savings and a more comfortable indoor environment.

Air curtains are often used in commercial or industrial environments where there are large door openings that are open for long periods each day. There are air curtains with water heating, electric heating, and air curtains without heating.

How does an air curtain work?

An air curtain works by using a fan to create a high-velocity airstream that is blown out through a nozzle. The air curtain is mounted at an opening between two different temperature zones, for example, between indoors and outdoors. This airstream creates an “invisible door” that helps reduce heat or cooling losses through the opening.

The principle behind air curtains is that the created airstream forms a layer of air that acts as an insulating barrier. When the air is blown out from the air curtain, it forms an “invisible door” that prevents the surrounding air from entering and the conditioned air from escaping, thereby helping to maintain the desired temperature indoors.

To function effectively, the air curtain must be correctly sized, installed, and adjusted so that the airstream remains cohesive and has the correct velocity when it meets the floor or an airstream from another air curtain (in the case of side-blowing air curtains).

By creating this “invisible door,” air curtains help reduce energy losses and create a more comfortable indoor environment while ensuring that different temperature zones are effectively separated.

Read more on air curtains

Air curtains can be used in a variety of environments and applications where there is a need to create an “invisible door” between different temperature zones or to prevent air exchange through openings.

• Commercial buildings: Air curtains are often used in commercial buildings such as shops, supermarkets, restaurants, and office buildings. They can be placed at entrances to reduce heat or cooling losses when doors are opened and closed regularly.

• Industrial facilities: In industrial environments where large door openings are used for material handling or vehicle traffic, air curtains can help maintain the indoor climate and reduce energy loss.

• Food industry: In food production facilities and grocery stores, air curtains can be used to maintain hygienic conditions by preventing temperature fluctuations and unwanted particles or contaminants from entering production or storage areas.

• Cold storage and freezer rooms: In cold storage and freezer rooms, air curtains can be used to minimize cooling loss and reduce the need for defrosting. Masterveil holds a patent on the most energy-efficient air curtain solution for freezer rooms, the Powerstream air curtain system, which in addition to being energy efficient also reduces energy consumption through the freezer door.

There are two main ways to install an air curtain, depending on the size and design of the door:

• Overhead Installation: The air curtain is installed horizontally above the opening and blows downwards towards the floor. This solution is well-suited for wide openings. The longest curtain Masterveil has made so far is approximately 100 meters.

  • Remark: Overhead air curtains are slightly more sensitive to wind load and drafts.

• Side-Blowing Installation: Air curtains are installed vertically on the sides of the opening. This is suitable for narrower openings and offers greater resistance to wind and drafts. For openings up to approximately 5 meters wide, double vertical air curtains can be used. If the door size and location allow for side-blowing air curtains, this is almost always the best solution for separating different temperature zones. For optimal function, one curtain should be installed on each side of the opening.

  • Remark: Side-blowing curtains have limitations in the width of openings they can cover. Installing only one curtain can result in the airstream bending inwards into the room shortly after the middle of the opening, bringing cold air into the room at high speed.

Ideally, an experienced installer recommended by the manufacturer should carry out the installation. However, if you feel you have the knowledge to install the air curtains yourself, it is possible to do so with support from your supplier.

The most important thing is that the supplier or someone trained by the supplier performs the adjustment after installation. If your supplier cannot offer an adjustment, you should choose another supplier. An incorrectly adjusted air curtain can lead to increased energy consumption and a poorer indoor environment instead of saving energy.

Choosing the right air curtain is essential to maximize its efficiency and performance. Here are some of the advantages of choosing Airstop technology over a conventional air curtain:

• Targeted Airflow: Airstop technology creates a concentrated airflow that effectively protects openings between two different temperature zones. This provides optimal protection against unwanted temperature fluctuations and contaminants.
• Increased Control: With Airstop technology, you can fine-tune the air velocity and direction to suit your specific opening. This gives you detailed control over the air curtain’s performance, which is invaluable in sensitive work environments.
• Energy Efficiency: By directing the airflow exactly where it’s needed, Airstop technology reduces the building’s energy consumption and operating costs. This is a cost-effective solution that helps save energy and resources.
• Improved Resistance: Airstop technology provides a tighter air barrier, which improves resistance and reduces heat/cooling losses. This is especially valuable where temperature control is important.

Click here to read more about the difference between standard curtains and Masterveil’s air curtains.

The maintenance of air curtains depends on the type of air curtain you have.

• Air curtains with water coils: Require regular filter cleaning or replacement. In dirty environments, more frequent maintenance is needed. The efficiency of fans in air curtains decreases when the filter becomes clogged with dust.
  • For compact air curtains with high pressure and low airflow, the filter replacement interval is typically 3-6 months, depending on the environment and the type of filter installed in the air curtain.
  • For air curtains with a separate air curtain unit with a water coil, filter replacement is usually sufficient once a year, but this also depends on the environment in which the air curtain is installed.
• Air curtains with electric heating and air curtains without heating: Usually do not have a filter, so only cleaning of the fans is required, approximately once a year.

In addition to filter replacement, you should also inspect the fans and wipe them down once a year.

If you do not want to perform the maintenance yourself, you can contact us at Masterveil, and we will be happy to help you with it.

In-depth troubleshooting of air curtains should be carried out by a professional with knowledge of air curtains, but you can perform a general check before contacting your supplier.

The first step is to check for any error messages on the air curtain’s control display.

• Masterveil’s ERX control system: The error message will be displayed in clear text, making troubleshooting quite simple.
• Other control systems: Perform a visual inspection of the following:
  • Service switch: Check its position (operating mode, operating status).
  • Set values and information: Check if the current values seem correct.
  • Fuses: Check that no fuses have blown.
  • Filter: Open the filter cover and inspect if the filter is clogged. A clogged filter can damage the fans and trigger the motor protection.
  • Freeze protection: A common problem is that the freeze protection on air- curtains is triggered. If the water temperature to the air curtain drops below approximately 7 degrees Celsius, the freeze protection will activate and shut down the air curtain.
  • Valve and actuator: If the air curtain is not heating, it may be because the valve is not opening properly or there is air in the system.
  • Door contact: If the air curtain does not switch to high speed when the door opens, it is usually because the door contact has been disconnected or is broken.
  • Temperature sensor: If it is too hot or cold near the opening, it may be because the temperature sensor is providing incorrect values. This could be due to it being broken, a cable break, or incorrect installation.
  • Fan: Is it making strange noises? Turn off the power to the air curtain and check if any visible debris is stuck on the fan. If you cannot see any debris, or if you are not comfortable checking the fan yourself, contact your supplier.

Please contact Masterveil if you need assistance troubleshooting your air curtain.