Modern air curtains conserve energy, maintain comfort

Block air movement, invisibly


Loading docks are an area frequently protected by air curtains. Typically, the unit switches on when the overhead door is opened. Courtesy: Enershield Industries.From the time we were children, we remember being told, “Close the door. We can’t heat the whole outdoors!” That problem is acute in manufacturing, warehousing, and shipping operations. Outside doors on loading docks, or passages between manufacturing and warehouse areas are sources of huge potential energy losses. Yet safe and rapid passage of pedestrians, lift trucks and even conveyors through those openings is essential. Various approaches have been tried, but one of the most attractive is the use of modern air curtains, sometimes called air barriers. 

Problems with Open Doors

Most manufacturing operations require frequent movement of pedestrians and vehicles between spaces with differing environmental conditions. It might be lift truck traffic between the manufacturing floor and warehouse or outdoor storage for parts, supplies or finished products. It might be loading docks for rail or truck access. It could even be wall openings for conveyor transfer of manufacturing inputs or outputs. In some industries, there is also a need for frequent traffic into and out of refrigerated or freezer areas.

The problem is that all of those openings allow the escape of conditioned air, and entry of undesired elements including dust, fumes or insects. Conventional doors are impractical because of traffic volume and because of the need for visual contact between areas for safety reasons. An approach that is sometimes used is suspended clear vinyl strips that push aside for vehicle or pedestrian passage. Although initially somewhat transparent, these strips quickly become scratched or clouded and visibility through the opening is lost, creating a safety hazard. Vinyl strips are also subject to damage by passing vehicles, so maintenance expense can be high. 

Air Curtains --  A Better Way

An alternative approach increasingly being adopted is the use of air curtains. These create an invisible barrier across openings while not impairing safety or quick passage of pedestrians and vehicles. The air curtain uses a high-speed laminar flow of air across the opening to effectively block air flow from either direction. 

Dan Hallihan is the National Sales Manager for Enershield Industries of Edmonton, Alberta. He explains that the barrier is mounted as close to the door opening as possible. “It takes facility air and disperses it across the doorway to create a 90% efficient barrier that prevents outside air from infiltrating in and inside air from escaping.” He recommends that for facilities that are trying to stop cold outside air from infiltrating, the air barrier be installed horizontally across the door opening so that it can pull waste heat from the ceiling area and recirculate it back into the facility.

For specialized applications where there is heavy pedestrian and vehicle traffic, air curtains maintain the environment while allowing convenient passage. Courtesy: Mars Air Systems.He notes that the Enershield system uses a nozzle that spans the full height or width of the doorway and can be angled as much as 25 degrees outward. Hallihan advises, “The angling of the nozzle is crucial in offering resistance to any outside air trying to penetrate the doorway.” The air barrier uses the facility air to create a wind shear effect on the doorway, sealing the opening efficiently. For applications that do not have adequate head-room above the doorway for horizontal installations, the units can be installed vertically and be just as effective.

Steve Benes is the Sales Manager for Berner International Corp., another major manufacturer of these devices. He notes, “The demand for air curtains continues to grow as North American manufacturing companies look for cost effective solutions and products to save energy or create a more comfortable environment for their employees or clientele.”

Benes explains that with the use of various types of mounting brackets and accessories, most existing openings can accommodate the addition of air curtains. He points out, “The most common obstruction to the installation of an air curtain is the placement of the hardware for a roll-up garage door. We provide several options for our customers to solve this. Our air curtain systems are compatible for new construction as well as retrofit applications.” 

A Clearer View

Even relatively large and high doors can effectively be controlled with industrial air curtains. Courtesy: Mars Air Systems.An important feature of the air curtain system is that it provides a clear view across the opening, helping to eliminate safety hazards from vehicle operators not seeing oncoming or crossing pedestrian or vehicle traffic. Where they are installed on multiple doors on loading docks, they typically turn on automatically when the overhead door is opened and shut off when it closes.

In many locations, preventing entry of outdoor insects is a high priority. This is a special concern for food processing or food service businesses. Benes notes that the U.S. EPA recommends the use of air curtains for integrated pest management (IPM) programs as a viable alternative to the use of pesticides. An application with which many are familiar is the use of air curtains across the windows in fast-food drive-up operations. 

Built to Last

Air barrier equipment is built to provide long service with minimum maintenance. Most standard models have welded frame and powder-painted surface. Manufacturers offer models for harsh climate conditions and for areas that require frequent washdowns. According to Julie Konowitz from Mars Air Systems, their air curtains keep their effectiveness through their entire operating life.

She notes that Mars provides architects, engineers and food service consultants with a comprehensive line of air curtains and air door products. “This is achieved while giving building owners peace of mind of a reliable product and dedicated support. Our newest product line, the Series 2, includes slimmer units, updated colors, and a sleek new design for everything from a drive-thru window to a lobby entrance to warehouse loading dock doors.”

Konowitz indicates that there is growing acceptance of efficiency and effectiveness of air curtains in the food processing and general manufacturing industries, focusing on energy savings and sanitation management. She says that many times the installations are aftermarket applications where a solution is urgently needed for temperature control or to inhibit airborne contaminants. If your facility is struggling with any of these challenges, it may be time to consider today’s efficient air curtain solution. 

More Info:

Enershield Industries

Berner International

Mars Air Systems 

No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2013 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
The true cost of lubrication: Three keys to consider when evaluating oils; Plant Engineering Lubrication Guide; 11 ways to protect bearing assets; Is lubrication part of your KPIs?
Contract maintenance: 5 ways to keep things humming while keeping an eye on costs; Pneumatic systems; Energy monitoring; The sixth 'S' is safety
Transport your data: Supply chain information critical to operational excellence; High-voltage faults; Portable cooling; Safety automation isn't automatic
Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Plant Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.

Maintaining low data center PUE; Using eco mode in UPS systems; Commissioning electrical and power systems; Exploring dc power distribution alternatives
Synchronizing industrial Ethernet networks; Selecting protocol conversion gateways; Integrating HMIs with PLCs and PACs
Why manufacturers need to see energy in a different light: Current approaches to energy management yield quick savings, but leave plant managers searching for ways of improving on those early gains.

Annual Salary Survey

Participate in the 2013 Salary Survey

In a year when manufacturing continued to lead the economic rebound, it makes sense that plant manager bonuses rebounded. Plant Engineering’s annual Salary Survey shows both wages and bonuses rose in 2012 after a retreat the year before.

Average salary across all job titles for plant floor management rose 3.5% to $95,446, and bonus compensation jumped to $15,162, a 4.2% increase from the 2010 level and double the 2011 total, which showed a sharp drop in bonus.

2012 Salary Survey Analysis

2012 Salary Survey Results

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.