GAS TECHNOLOGY: Air Curtains Can Make a Difference

Invisible Wall to Separate Environments

11/12/2010


One of the most frustrating problems for industrial building energy managers is large openings between conditioned and non-conditioned spaces. Often dock doors, warehouse access doors and other openings need to be kept open to facilitate movement of personnel, equipment and goods. Unfortunately, these openings also represents a major building energy leak and source of indoor contamination. A solution to this challenge that is increasingly being used is air curtains, sometimes called air barriers. These can not only help reduce energy loss, but can prevent entry by other environmental contaminants such as fumes, dust and insects.

 

Challenges Where Environments Meet

Most industrial buildings have several openings to the outdoor environment, or openings between a non-conditioned warehouse environment and conditioned storage or manufacturing spaces. These are problem areas because forklift, conveyor and foot traffic require that doors be kept open much of the time. Yet open doors allow the escape of conditioned air and entry of outdoor air contaminants. Various solutions have been tried.

One approach has been to use suspended vinyl strip doors. While these can be effective in separating environments, they have several drawbacks. According to one industry spokesperson, “Vinyl strip doors are unsightly and do not provide effective environmental separation.”

 

Potential Visibility Hazard

Though quite transparent when new, vinyl strips quickly become scratched, stained and dusty, particularly if they are used for
motorized traffic, creating a potential hazard for traffic through or near the doors. When there is a breeze on one side of the door, they are of limited usefulness in preventing intrusion of outdoor conditions. They can require frequent maintenance because the strips are often damaged by forklift operations.

In addition to doors to the outside and between conditioned and non-conditioned spaces, another area where environmental separation is needed is entrances to refrigerated spaces and freezers, particularly where forklift transport is being used. Where these are high-traffic entrances, physical barriers like motorized doors or vinyl strips are impractical and inevitably slow down production. Here also, a better solution is needed.

 

A Better Solution for Reducing Infiltration

The approach that is gaining in popularity is the use of air curtains. These use an overhead air pressurizer that directs a narrow laminar flow of recirculated air down or across the door opening. This high-speed stream prevents entry of outdoor environmental elements and escape of conditioned indoor air. This is achieved without any visual or physical barrier to foot or motorized traffic.

Enershield Industries, headquartered in Edmonton, Alberta, is a manufacturer of air barriers for the U.S. and Canadian markets. Dan Hallihan is the Regional Manager for the firm and was a recent presenter at a Tecnology & Market Assessment Forum sponsored by the Energy Solutions Center. Hallihan indicates, “One of the greatest energy inefficiencies in any building is an open door. Enershield Air Barriers can create up to a 90% seal on open doors against a 15 mph wind. We supply our clients with an energy loss calculation using an ASHRAE formula to show what the client is losing in energy as well as what we can save them based on the amount of time the door is opened. “

Hallihan feels there are numerous locations in the industrial building where it is important to prevent the infiltration of outside air into facilities. “This not only affects indoor temperatures but in some cases also affects manufacturing processes. When outside air infiltrates into a facility, it puts an instant demand on either the heating or cooling system. The installation of an air barrier helps to reduce the cycle time of those systems and thus reduces wear and tear on those units and saves facility energy.”

Air curtains are often designed to start automatically when the physical door is opened and stop when it is closed. Often, conditioned warehouse facilities have rows of multiple bay doors. Where each of these is equipped with an air barrier, the indoor environment remains stable and comfortable, and temperature sensitive products and equipment are protected. Air curtains are available for doors in a wide range of sizes. Systems are available for openings as small as retail food takeout windows, or as large as aircraft hangar doors.

 

Air Barriers Withstand Tough Environments

Standard models are typically constructed of a welded, powder-coated frame with a galvanized metal jacket. Manufacturers also produce models for harsh, damp climates or areas that require a frequent washdown and need to be able to tolerate a wet environment. Other considerations in specifying an air barrier are building orientation to prevailing winds and the local climate.

Another provider of air curtains is Mars Air Systems of Gardena, California. Mars offers a broad line of air curtains for door and window openings of virtually all sizes. Betiel Abraham from Mars emphasizes that their air curtains help maintain comfortable indoor temperatures, so employee productivity increases and energy costs decrease. Abraham also points out that through the use of air barriers, an industrial or commercial facility can garner points toward a LEED certification.

 

Air Curtain Heating Available

For users of air curtains in cold climates, Mars offers doors that use heated air to increase comfort for workers near the opening. Several heating options are available, including electric, gas-fired hot air and steam heat. The Mars website includes a calculator to help owners determine potential energy savings through the use of an air door. According to Abraham, the doors can be installed over any door opening and are available in a variety of colors. “These can be customized to conceal into any opening and are available with a standard five year warranty on all unheated systems and and 18 month warranty on heated units.”

As energy costs become increasingly critical with tight manufacturing margins, the savings and improved environment realized from an air curtain can be important. Engineers have designed air curtains to solve the challenges of traffic safety, energy conservation, facility comfort and control of the indoor environments. Now is the time for owners to take a look at this valuable technology.

 

More Info

Biddle Air Systems
www.biddle-air.co.uk

Enershield
www.enershield.ca

Mars Air Systems
www.marsair.com

Powered Aire, Inc.
www.poweredaire.com



Top Plant
The Top Plant program honors outstanding manufacturing facilities in North America.
Product of the Year
The Product of the Year program recognizes products newly released in the manufacturing industries.
System Integrator of the Year
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
October 2018
Tools vs. sensors, functional safety, compressor rental, an operational network of maintenance and safety
September 2018
2018 Engineering Leaders under 40, Women in Engineering, Six ways to reduce waste in manufacturing, and Four robot implementation challenges.
July/Aug
GAMS preview, 2018 Mid-Year Report, EAM and Safety
October 2018
2018 Product of the Year; Subsurface data methodologies; Digital twins; Well lifecycle data
August 2018
SCADA standardization, capital expenditures, data-driven drilling and execution
June 2018
Machine learning, produced water benefits, programming cavity pumps
Spring 2018
Burners for heat-treating furnaces, CHP, dryers, gas humidification, and more
October 2018
Complex upgrades for system integrators; Process control safety and compliance
September 2018
Effective process analytics; Four reasons why LTE networks are not IIoT ready

Annual Salary Survey

After two years of economic concerns, manufacturing leaders once again have homed in on the single biggest issue facing their operations:

It's the workers—or more specifically, the lack of workers.

The 2017 Plant Engineering Salary Survey looks at not just what plant managers make, but what they think. As they look across their plants today, plant managers say they don’t have the operational depth to take on the new technologies and new challenges of global manufacturing.

Read more: 2017 Salary Survey

The Maintenance and Reliability Coach's blog
Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
One Voice for Manufacturing
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 Maintenance and Reliability Professionals Blog
The Society for Maintenance and Reliability Professionals an organization devoted...
Machine Safety
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
Research Analyst Blog
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Marshall on Maintenance
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
Lachance on CMMS
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
Material Handling
This digital report explains how everything from conveyors and robots to automatic picking systems and digital orders have evolved to keep pace with the speed of change in the supply chain.
Electrical Safety Update
This digital report explains how plant engineers need to take greater care when it comes to electrical safety incidents on the plant floor.
IIoT: Machines, Equipment, & Asset Management
Articles in this digital report highlight technologies that enable Industrial Internet of Things, IIoT-related products and strategies.
Randy Steele
Maintenance Manager; California Oils Corp.
Matthew J. Woo, PE, RCDD, LEED AP BD+C
Associate, Electrical Engineering; Wood Harbinger
Randy Oliver
Control Systems Engineer; Robert Bosch Corp.
Data Centers: Impacts of Climate and Cooling Technology
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
Safety First: Arc Flash 101
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
Critical Power: Hospital Electrical Systems
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
Design of Safe and Reliable Hydraulic Systems for Subsea Applications
This eGuide explains how the operation of hydraulic systems for subsea applications requires the user to consider additional aspects because of the unique conditions that apply to the setting
click me