Page 76 - Occupational Health & Safety, June 2019

HEAT STRESS
tribute air more effectively, and industrial curtain walls to create easily controllable temperature zones.
While adding air conditioning is the best-case scenario, it isn’t always practi- cal due to cost considerations and build- ing configurations. With or without air- conditioning, facilities dealing with heat stress challenges will find relief from HVLS fans. Although smaller, floor-mounted fans can be helpful in limited spaces, their high wind speed and noise levels may cause problems. They also use a relatively high amount of electricity. HVLS fans, on the other hand, use relatively little energy and provide a gentle, quiet breeze that is very comforting to workers. In fact, some HVLS fans use gearless motors that run with vir- tually undetectable noise.
According to the U.S. Department of Health and Human Services paper “Work- ers in Hot Environments,” a 2-3 mph air speed creates an evaporative cooling sen- sation of 7-11 degrees F. To put this in perspective, the effective temperature of an 84-degree warehouse environment can be dropped to 73 degrees by adding a fan moving air at 3 mph. A single HVLS fan can move large volumes of air up to 22,000 square feet and replace as many as 20 floor fans. By mixing air, HVLS fans also help air-conditioning systems work more effi- ciently, allowing them to be operated at a set point up to 5 degrees lower.
There are a number of factors to con- sider when deciding how and where to use HVLS fans. They include obstructions such as pallet racks, machinery, and product staging; personnel work areas; and over- all building layout. HVLS fans that are 24 feet in diameter can move air further down rack aisles and over obstructions. Smaller diameter fans in the 8- to 12-foot range can be most effective in specific work areas or where installation space is limited.
For even more environmental and en- ergy control, as many as 24 HVLS fans can be linked into a single network that can be easily managed with one device. This can greatly reduce maintenance challenges in facilities that have ambient sunlight or temperature-effecting operations (such as loading docks) in one part of the building, but not another.
That controller allows for independent speed adjustments, scheduled start/stop times, and the ability to start/stop based on
preset temperature settings. It also ensures that fans are running only when they need to, reducing energy use.
An optional Ethernet port allows the system to be accessed via a remote device so they can be controlled via smartphone or other mobile device. Additionally, they can be programmed into a building man- agement system (BMS) and connected to other infrastructure equipment such as ex- haust fans. A “fire stop” option is also avail- able, in which the BMS will automatically turn off the HVLS fans and activate sprin- klers in the event of a fire.
Efficient Air Distribution with Fabric Ductwork and Diffuser System While metal duct systems have been used to distribute air in buildings for decades, fabric dispersion systems are becoming more prevalent. They are used in a variety of industries that require precise air flow. The main benefits of fabric systems when compared to traditional metal counterparts is that they are custom designed for the ap- plication to provide even airflow through- out the space. Additionally, a fabric system has lower material, installation, and life- time ownership costs.
Similar to how HVLS fans can lower the perceived temperature in specific areas, fabric dispersion systems provide targeted, precise, efficient air flow throughout the length of their run. Fabric diffusers use various methods to achieve this uniformi- ty, including air porous fabrics, linear vents, nozzles, and orifices. Any of these methods will be more effective than standard met- al ductwork that uses localized diffusers spaced many feet apart, creating hot and cold spots along the length of the system.
The various types of fabric dispersion products allow facility managers to spec- ify the performance requirements that will best serve their environments. One of the most significant benefits of fabric ducts is their complete customization for each application. Whether it’s providing the exact temperature for food products or helping to cool off workers in a 3PL, fabric diffusers help ensure maximum environmental control.
Fabric ducts are fairly easy to install. Be- cause they’re significantly lighter and more flexible than their metal counterparts, in- stallation is usually faster, there’s less of a load on the ceiling structure, and setup
costs are lower.
Manage Temperature Zones
with Curtain Walls
Large warehouses and storage facilities are designed to provide the maximum amount of space for storing products. However, this often results in large spaces that are extremely difficult to cool down. Creating smaller spaces can be a cost-effective way to manage temperatures.
By using fabric curtain walls, facil- ity managers can easily create compart- mentalized spaces for specific processes or employee comfort and safety. Creating temperature-controlled zones makes it possible to be much more efficient with HVAC expenditures, instead of heating or cooling unnecessarily large areas. Be- cause of their modular design, industrial curtain walls can easily be reconfigured if a space needs to be enlarged or reduced or the shape of the footprint needs to change. They are also durable enough to withstand contact from machinery and can provide up to 40 degrees Fahrenheit of temperature separation.
Insulated curtain walls with vinyl- covered surfaces are ideal in separating two different temperature zones, as hu- midity can be a concern. Their surface is waterproof and the insulation inhibits the transfer of heat away from the outer sur- face, keeping the outer surface temperature above the dew point of the exterior air so there is no condensation.
Fabric curtain walls can be easily in- stalled, trimmed to fit around conduit, pip- ing, or ductwork, and anchored to the floor to withstand pressure differential. Depend- ing on the application, a curtain wall can be suspended from the room ceiling or they can hang from a stand-alone framework. They are available as stationary and slid- ing applications and can be fitted with strip curtains, personnel doors, or high-speed industrial doors.
Andy Olson is marketing director at Rite- Hite. The information herein is provided as a general reference regarding the use of the applicable product(s) in specific applications. This information is provided without war- ranty. It is your responsibility to ensure that you are using all mentioned products prop- erly in your specific application and in accor- dance with all laws and regulations.
72 Occupational Health & Safety | JUNE 2019
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