Air Curtain 101

If you have been thinking about installing an air curtain at your business, there are probably a few things you want to know first. What are air curtains exactly? How do they work? What are their benefits? And where are air curtains typically used? This guide will seek to answer those questions and more. So, if you want to learn a thing or two about air doors or air curtains, keep reading!

Table of Contents

  1. What Are Air Curtains?
  2. How Do Air Curtains Work?
  3. What Are the Uses for Air Curtains?
  4. Where Are Air Curtains Used?
  5. What Are the Benefits of Air Curtains?
  6. What Types of Air Curtains Are Available?
  7. What Are Some of the Leading Air Curtain Brands?
  8. What Can You Expect from the Air Curtain Installation Process?
  9. How Can You Select the Right Air Curtain for Your Needs?
  10. What Are the Latest Air Curtain Technologies and Features?

How Air Curtains & Air Doors Work


What Are Air Curtains?

Air curtains, also known as air doors, are devices that produce a controlled stream of air across an opening in a wall. What this technology does is create a barrier or seal of air that protects an environment from specific issues while still allowing quick and unimpeded passage for people, animals, equipment, or the like.

For instance, say you run a restaurant and want to keep the door open during business hours in the summertime. Having the door open invites passerby inside, increases the amount of natural light making it to your space, opens views and sightlines, and can make people eating outdoors feel like they are still a part of your establishment. If you do have outdoor diners, then leaving your door open can also help your wait staff enjoy easy passage to those tables— vital if they have their hands full with plates, drinks, or heavy trays.

There are clear benefits to leaving the door of your restaurant open during business hours, and some of these benefits carry over to other types of businesses as well. However, there are also drawbacks to having an open-door policy. For instance, on hot days, you risk losing most of your cool, air-conditioned air through the open door. You also risk letting flying pests, such as flies or gnats, into your restaurant. Dust and debris, especially if the entrance to your business is close to a busy street, is another problem.

Air curtains help to solve all these issues. The controlled stream of air creates an invisible barrier where your closed door would be. People can pass through this barrier just fine, which means you enjoy the benefits that an open-door policy can bring to your restaurant. At the same time, the curtain of air helps contain hot or chilly air, stop the infiltration of flying insects, and knock debris out of the air before it crosses your threshold. All these benefits explain why air curtains are becoming more popular—not just in the food service industry, but in every corner of the commercial world.

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How Do Air Curtains Work?

Now we know what air curtains do, but how do they work?

There are two answers to this question, thanks to the fact that there are two distinct types of air curtain. The first type is called a non-recirculating air curtain. These air curtains tend to be the most popular among many businesses because they are less expensive to install and cost less to maintain. The second type is called a recirculating air curtain. These air curtains cost more money to install and maintain but are also more powerful and effective as air barriers. These air curtains tend to be ideal for entrances with unusually high levels of foot traffic.

Both types of air curtains bring air into the system through an intake grille and then use a fan to propel or accelerate the air. The air passes through what is called a plenum, which helps evenly distribute it and ensure a consistent stream of air along the entire length of the air curtain. Since most air curtains are installed at the top of a door opening, the air then shoots down, covering the opening with what is, in fact, a waterfall of air.

Non-recirculating air curtains only consist of a top unit, which sits above a door or opening and discharges air downward. Recirculating units, meanwhile, look like high-tech doorframes or metal detectors. They have a full square or rectangular design that spans all sides of the door opening. This design allows the air discharged at the top of the air curtain to be collected at the bottom of the curtain and recirculated back to the top.

Because they repeatedly reuse the same air to create an accelerated stream of air, recirculating air curtains are more energy efficient than non-recirculating units. However, because of their more complex design, it is more difficult to install them retroactively. Most recirculating air curtains, therefore, are mounted at a building entrance at the time of construction. Otherwise, these units can be expensive to install and can require more extensive renovation work than business owners are prepared to approve.

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What Are the Uses for Air Curtains?

We have already touched upon the primary uses of air curtains, but for a refresher, they typically fall into three main categories:

  • Climate control
  • Flying insect and debris control
  • Comfort

Climate control is likely the top application for air curtains among most commercial enterprises. In businesses where people are continually going in and out, or where leaving a door open just makes sense for business purposes, there is always the risk of heat transfer. During winter, warm air will be lost through the open door while the opposite is true in summer. Both occurrences will cause your HVAC system to work that much harder to reach the temperature you have set on your thermostat. You will see the effect of this extra operational effort in the form of higher energy bills. Air curtains provide an effective way of preventing temperature transfer, preserving a comfortable temperature inside your business while still letting you have an open door.

Flying insect and debris control are notable as well. In the summertime, winged insects such as flies, gnats, bees, and mosquitos can fly through open doors and windows and terrorize your employees or customers. Air curtains let you enjoy a nice open-air feel in your establishment while still knowing that those flying insects are going to be blasted out of the air if they try going through the air curtain.

Air curtains work similarly for debris control. If your business is in a sandy or dusty area, you might fear that every time the door opens, it’s going to let another plume of debris into your business. Similar issues exist in areas where there is a lot of pollen in the air during the springtime, or if your business is near a construction site and you want to prevent all that debris from getting indoors. Air curtains are powerful enough to knock those grains of dust out of the air before they enter your business.

The last reason that many businesses install air curtains is for pure comfort. Patrons enjoy an environment that is heated or cooled to a comfortable temperature. However, they do not enjoy drafts of hot or frigid air hitting them every time the front door opens. Air curtains can prevent drafts and preserve consistent temperature, for maximum comfort.

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Where Are Air Curtains Used?

Virtually any business can benefit from an air curtain in one way or another. Issues such as heat transfer, flies that won’t go away, dust or pollen, and drafty air are not sequestered to any one industry. Instead, these issues can affect any company in any field, making the potential applications for air curtains nearly unlimited.

With all that said, here are some of the business types that tend to benefit the most from an air curtain installation:

  • Restaurants: Air curtains can help restaurant owners create a homey, airy environment without sacrificing comfortable temperatures and energy efficiency, and without welcoming fumes, dust, or winged insects into the dining room.
  • Cold Storage Facilities: Every time someone opens the door to a cold storage room or facility, it results in heat transfer. Cool air might escape, resulting in higher energy costs, or warm air might invade, risking food spoilage. An air curtain mitigates both risks.
  • Commercial Kitchens: In commercial kitchens, air curtains can have several benefits, from keeping flying insects away from the food to preventing smoke from the employee smoking area from getting into the kitchen.
  • Fast Food Restaurants: In fast food restaurants, doors (and drive-through windows) are opened all the time. Every opening affects the temperature of the restaurant and risks letting automobile fumes, flying insects, or other toxins/contaminants into the space. Well-placed air curtains can prevent all these issues.
  • Cafeterias: In cafeterias—whether in schools, hospitals, or other establishments—it’s essential to allow for constant foot traffic while also blocking airborne pests, dust, fumes, odours, smoke, and cold or hot air. Air curtains do the job.
  • Supermarkets: Flying pests, dust, airborne particles, and other contaminants in supermarkets can ruin food or spread infections. Failure to preserve a consistent interior temperature, meanwhile, can lead to food spoilage and steep Air curtains minimize these risks while still allowing for high shopper traffic.
  • Food Processing Plants: A single issue with a food processing plant can contaminate thousands of shipments of food, forcing costly recalls and damaging branding disasters. Air curtains help ensure cleanliness and safe interior temperatures at these facilities, thereby protecting food quality and consistency.
  • Distribution Centers: People and vehicles are always going in and out of distribution centers, to the point where it becomes tough to maintain consistent temperatures in these buildings. Air curtains make it possible.
  • Bakeries: Bakeries face the same threats as food processing plants, just on a smaller scale. In the same way that air curtains help processors curb the risks of infestation, contamination, or temperature imbalances, they also deliver those benefits for bakeries.
  • Warehouses: Warehouses are often used to store medicines, foods, and other consumable goods. Flying insects, dust, smoke, fumes, and other pollutants can affect these goods, risking the health of the people who will ultimately consume them. Air curtains help ensure that these goods are always stored in a controlled environment.

The list goes on forever, but the bottom line is clear: the benefits of air curtains are universal and can be applied to virtually any commercial business. 

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What Are the Benefits of Air Curtains?

At this point, the main benefits of air curtains should be reasonably clear. However, we’ve provided a rundown below, just for quick reference.

  • Energy Savings: Issues with heat transfer impair the efficiency of your heating or air conditioning system, leading to higher energy costs. By offering superior climate control benefits, air curtains help you cut your monthly energy bill significantly.
  • Climate Control: Regarding climate control, air curtains help form barriers between spaces with differing air temperatures. This separation ensures more consistent interior temperature, which is more comfortable for customers, guests, and employees.
  • Pest Control: At best, flying pests such as bees or fruit flies can be a nuisance. At worst, they can contaminate food, ruin wine, spread disease, or cause allergic reactions. Flying pests hate air curtains and can’t go through them without losing control and becoming disoriented.
  • Environmental Friendly: Air curtains deliver the benefits above without posing a threat to the environment. The systems don’t use chemicals or anything environmentally damaging to achieve an effect: they only use air. The systems are also energy efficient (especially recirculating air curtains) and help preserve energy in general.

These four benefits are the cornerstones of virtually any argument in favor of air curtain adoption.

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What Types of Air Curtains Are Available?

There are several types of air curtains currently available on the market. These varieties include (but are not limited to) ambient air curtains, electrically heated air curtains, steam coil air curtains, and gas-fired air curtains. Read below for additional details on these types of curtains.

  • Ambient (Unheated) Air Curtains: Ambient air curtains are used most often for insect and environmental control and can be used at any door opening. Typically, this variety of air curtain is mounted on the inside of the door opening. Indoor mountings are ideal for environmental control (such us as blocking out fumes, dust, and pollen) ambient air curtains mounted outside the door are equally reliable for insect control. These curtains are incredibly sustainable and use very little energy to separate indoor air from outdoor air.
  • Electrically Heated Air Curtains: Electrically heated air curtains are used for areas that need supplemental heat in and around open doorways to prevent cold drafts from entering the building. Restaurants, hospitals, and retail stores love heated air curtains, as they increase creature comfort indoors. As patrons come in from cold or blustery outside conditions, these curtains keep the cold out and the warm, comfortable air inside. These air curtains are useful year-round, as the heating component can be turned off in the summertime.
  • Steam/Hot Water Coil Air Curtains: Steam or hot water coil air curtains are used to tap into a building’s existing heating system. In many parts of the country, steam and hot water are utilized to keep buildings heated in the winter. Heat loss through open doorways is a huge problem in these areas, so using a hot water or steam-based air curtain is an effective way to heat the doorway and prevent cold air from entering. Again, these air curtains can be used in the summertime, by merely switching off the heating component.
  • Indirect Gas Fired Air Curtains: Indirect gas-fired air curtains are used most frequently in warehouses, manufacturing buildings, distribution centers, or similarly large buildings. These buildings use propane or gas for heat. They struggle with heat loss due to constant indoor/outdoor traffic. Still, keeping employees warm in these environments is vital, as it increases morale and productivity. Indirect gas-fired air curtains help with that mission by creating a comfortable environment. Also, many factories and warehouses require stable temperatures for sensitive products. Air curtains can stabilize temperature fluctuations even as doors open and close. Indirect gas-fired units are particularly useful here, providing a barrier against cold temperatures and winds up to 30 miles per hour. Like other heated air curtains, the heating component on these systems can be switched off during summer.

air curtain purchasing criteria

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What Are Some of the Leading Air Curtain Brands?

The biggest brand names in the air curtain industry right now are Berner and Mars.

Berner International

Berner (known more technically as Berner International) is a company that dates all the way back to 1956. Berner was the first business to manufacture air curtains in the United States. It was also the company that, in the 1970s, did the legwork to create a certified system for rating the performance of different air curtain devices. Today, Berner’s influence is felt on the air curtain market. The company itself, meanwhile, continues to develop air curtains for a range of commercial entities, including restaurants, manufacturing companies, warehouses, retail stores, hospitals, airports, hotels, and more. For more information on Berner air curtains and air doors, click here.

Mars Air Systems

Mars is also a long-running air curtain brand, having been around for more than 55 years. While not the industry pioneer that Berner was, Mars has nonetheless become a fierce competitor for the leading position in the market today. Mars manufactures several of the most well-known and well-regarded air curtain products available, including series such as the LoPro and the Phantom. Like Berner, Mars serves a range of different business industries, including restaurants, cold storage, transportation, healthcare, education, and more. For more information on Mars air curtains and air doors, click here.

Williams Comfort Products

Probably the next most well-known air curtain manufacturer is Williams. Unlike Berner and Mars, Williams is not exclusively dedicated to air curtains. The company also manufactures heating solutions, air handlers, and dehumidifiers. For more information on Williams air curtains, click here.

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What Can You Expect from the Air Curtain Installation Process?

As mentioned previously, how extensive the air curtain installation process is will depend on whether you choose a recirculating model or a non-recirculating model. Non-recirculating models cost next to nothing to install because the process involves little more than mounting the curtains above a door. With recirculating models, you can expect to pay a lot more for installation, as you will need to execute a fundamental redesign of your entryway. The installation process will also take longer and will be more invasive to the rest of your space.

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How Can You Select the Right Air Curtain for Your Needs?

The best air curtains will deliver all the benefits that we have discussed in this guide. As such, the most significant factors at play when you are choosing an air curtain will likely be size, design, and price. 

Regarding size, the implications should be obvious. Air curtains vary in length and size, which means that some air curtains are only suitable for smaller doors while others are terrific for larger entryways. Your best bet here is to measure the dimensions of the door/opening where you will be installing the air curtain and then shop accordingly.

The design will also be a factor. For instance, if you need an air curtain for a warehouse garage door, you are going to need a fundamentally different air curtain than you would need for the front door of your principal office establishment. If you have any special needs from a design standpoint, be sure to clarify those before you call a sales associate or start searching online. 

Lastly, the price is a factor. Air curtains can vary in price from a few hundred dollars to a few thousand, depending on size, design, type, and purpose. If you are shopping on a budget, you probably want to keep the cost down where possible, which might mean skipping the recirculating air curtain (among other things). Price shouldn’t be everything here since you want a high-quality unit that is going to deliver years of consistent and quality benefits. However, you also shouldn’t break the bank if you don’t have the budget available to do so right now.

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