Manufacturing comfort

Indoor air quality: Air movement needed in supply chain facilities


Figure 1: Temperature and air quality are two important factors that require attention when considering plant productivity. Courtesy: Big Ass FansThat comforting feeling created by an outdoor breeze on a hot summer day is equally satisfying to workers within a warehouse setting where fluctuating temperatures and stagnant air are the norm. Considering your equipment is only as good as the people using it, creating a comfortable work environment with the simple addition of air movement improves the health, safety, and sanity of those within.

Supply chain facilities are prone to these fluctuating temperatures; it’s an unfortunate reality of warehouse design. Air-conditioning and ventilation systems, while effective up to a certain point, can be greatly enhanced by the addition of proper air movement. When interior conditions are such that workers can no longer concentrate on the job at hand, personal comfort must be addressed. 


In terms of employee comfort, it’s important to understand that the sensation of feeling comfortable is not dependent on air temperature alone. Human thermal comfort takes into account numerous environmental factors including temperature, thermal radiation, humidity, and air speed as defined by ASHRAE Standard 55-2010, along with personal factors including activity level and clothing type. Studies have shown that improved occupant comfort leads to increased productivity, with worker productivity decreasing as temperatures rise above 77 F. 

The spin

In warmer months, operating between 60% and 100% of maximum speed, 6- to 24-ft-diameter fans improve comfort with either an evaporative cooling effect or the added effect of heat transfer—when skin temperature is warmer than air temperature. Although fans do not lower the air temperature in a space, the perceived cooling effect can make a person feel up to 10 degrees cooler.

In the winter months, operating at 10% to 30% of the maximum speed, large-diameter, low-speed fans successfully destratify tall spaces, mixing the warm air at the ceiling level with the cooler air at the occupant level, creating a more uniform temperature.

The addition of air movement offers multiple benefits that improve the well-being of occupants and, in some cases, of products and machinery as well, by aiding in the following:

  • Reducing heat stress on employees
  • Reducing condensation to preserve product integrity
  • Improving indoor environmental quality (IEQ), when mold or toxic fumes are airborne
  • Providing year-round comfort 

Heat stress

OSHA standards indicate temperatures of 100.4 F and above are dangerous for workers while air temperatures that exceed 95 F significantly increase the heat load on the body. When temperature and humidity rise, the body’s ability to cool itself decreases, severely affecting worker productivity. 

In the manufacturing industry, reducing activity level is generally not an option, but applying gentle, nondisruptive airflow from large-diameter, low-speed fans bring about the evaporative cooling process.

A Texas-size problem

A Texas-based McGraw-Hill textbook distribution center faced up to 15 heat-related incidents each summer in its 900,000-sq-ft facility. The 200 workers who boxed and shipped textbooks needed to ramp up productivity during this time in preparation for the fall semester, but the extreme Texas heat made this a tricky proposition.

Thirty 24-ft diameter fans were installed to help circulate the air. “It was an oven in this concrete building, and when workers were hot, they slowed down,” said Mike Price, maintenance manager. “We’ve noticed a big difference (installing the fans). One hundred and five is still hot, but it’s manageable inside with the fans.” 

Blowing condensation to bits

Figure 2: Condensation is another that HVLS fans can help solve. Condensation is an issue of safety, especially on concrete floors. Courtesy: Big Ass FansCondensation within a warehouse space can prove detrimental to employee safety (e.g., forklifts on wet concrete) and negatively affect product integrity. Dehumidification systems (air conditioning) can decrease moisture content of the air, while heating systems help increase air or surface temperatures to help reduce moisture buildup.

The downside however, is that large industrial spaces are often impractical, or at the very least expensive to heat and cool. Air movement, on the other hand, does not depend on any external conditions to be effective.

Properly designed large-diameter fans with airfoils and winglets disturb the thin film of stagnant air on the metal surface, which in turn dramatically reduces the likelihood of condensation. This is highly beneficial in areas of high humidity where moisture buildup can result in mold and mildew.

Where condensation is a concern, the temperature of a concrete slab will trail the air temperature by about a month. For example, as April’s air warms to 70 F, the concrete is still stuck at roughly 50 F, from the month before. This warm, moist air sits on the cold slab and deposits moisture as it cools.

Given the vastness of most facilities, the steady, even air movement from large-diameter, low-speed fans helps move the stagnant warm air off the cold surface before it has a chance to cool down enough to leave puddles. Fans with additional blade-ending fins can help direct the fan's airflow toward the floor, maximizing the fan’s coverage area. 

<< First < Previous 1 2 Next > Last >>

No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Choosing controllers: PLCs, PACs, IPCs, DCS? What's best for your application?; Wireless trends; Design, integration; Manufacturing Day; Product Exclusive
Variable speed drives: Smooth, efficient, electrically quite motion control; Process control upgrades; Mobile intelligence; Product finalists: Vote now; Product Exclusives
Machine design tips: Pneumatic or electric; Software upgrades; Ethernet advantages; Additive manufacturing; Engineering Leaders; Product exclusives: PLC, HMI, IO
This article collection contains the 5 most referenced articles on improving the use of PID.
Learn how Industry 4.0 adds supply chain efficiency, optimizes pricing, improves quality, and more.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Cyber security cost-efficient for industrial control systems; Extracting full value from operational data; Managing cyber security risks
Drilling for Big Data: Managing the flow of information; Big data drilldown series: Challenge and opportunity; OT to IT: Creating a circle of improvement; Industry loses best workers, again
Pipeline vulnerabilities? Securing hydrocarbon transit; Predictive analytics hit the mainstream; Dirty pipelines decrease flow, production—pig your line; Ensuring pipeline physical and cyber security