Controlling Temperature and Humidity with HVLS Fans and Curtain Walls

Temperature and humidity are critical components in the food industry. The temperature and humidity levels at which products are manufactured, stored and delivered all directly affect quality, and play a role in the reputation and success of production facilities and distributors.

Temperature and humidity are two critical components in the food industry. The temperature and humidity levels at which products are manufactured, stored and delivered all directly affect quality. As such, they play a major role in the reputation and long-term success of both production facilities and distributors.

Implementing a temperature and humidity control infrastructure is thus a high priority for most food facility managers. High-volume, low-speed (HVLS) fans and industrial curtain walls are two simple, cost-effective ways to develop such an infrastructure and strengthen quality controls.

HVLS Fans for Any Season

The environmental benefits of HVLS fans in both hot and cold weather have been well documented. In steamy climates, they can help industrial facilities guard against heat stroke, heat exhaustion and other heat-related maladies by providing workers with an evaporative cooling sensation. Just a 2–to-3 mph breeze can reduce the effective temperature by seven to 11 degrees Fahrenheit, making employees safer and more productive. In air-conditioned facilities, the breeze from an HVLS fan typically allows up to a five degree F increase in thermostat setting with no change in comfort. With an electric bill savings of four percent for each degree, an annual savings of 20 percent can be achieved in warm-weather climates.

HVLS fans’ benefits are often even more pronounced during the winter months. They mitigate the rising heat effect by destratifying layers of heated air as they gently circulate warm air from the ceiling back toward employees at the floor level. Thus, facilities equipped with HVLS fans reduce the burden on their heating system and are able to lower the set point on the thermostat — reducing energy consumption, and saving money.

BMS/HVLS Integration

For even more environmental and energy control, as many as 18 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 — a feature that can be very important in food operations, such as produce, cheese or wine storage. It also ensures that fans are only running 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 management system (BMS) and connected to other infrastructure equipment such as exhaust fans. A “fire stop” option is also available, in which the BMS will automatically turn off the HVLS fans and activate sprinklers in the event of a fire.

Increasing Cooler and Freezer Efficiency

The same energy efficiency benefits that HVLS fans provide in public areas can be applied in another important area of many food storage operations — industrial coolers and freezers.

Through destratification, HVLS fans can help stabilize temperatures in many coolers and freezers from floor to ceiling, allowing the thermostat set point to be more accurate. Creating a more uniform temperature throughout a cooler or freezer can help minimize the chance of freezer burn on products stored near the floor, and translates into energy savings since the freezer doesn’t have to work as hard to maintain the desired temperature. (NOTE: This does not apply to blast freezers.)

Controlling Humidity is Essential

Humidity is an environmental concern that is relevant to many industries, but is especially important in food manufacturing. Most humidity control applications simply involve separating a higher humidity space from a lower humidity space. For example, some food storage plants might be interested in preserving a high humidity environment for short term storage of vegetables, lettuce and spinach. In this situation, insulated curtain walls are a great solution.

Humidity and temperature are closely related. A change in the air temperature will cause an automatic change in relative humidity. Therefore, it is important to control temperature when trying to control humidity.

Maintaining a Low Humidity Space

Maintaining a low humidity space in the midst of a high humidity environment requires two basic components: 1) an insulated barrier to surround the space; and 2) a mechanical chiller to de-humidify, cool, and circulate the air within the space. An insulated barrier is desired so that the exterior surface of the barrier does not become cool enough to drop below the exterior (higher humidity) dew point, causing condensation (moisture) on the exterior of the barrier.

An insulated curtain wall is an excellent choice for this barrier. In addition to an insulated curtain wall’s benefits of adaptability, quick installation and re-configurability, the vinyl-covered surfaces typical of most curtain walls are inherently waterproof, protecting the insulation inside from the effects of condensation. The insulation itself inhibits the transfer of heat away from the outer surface, keeping the outer surface temperature above the dew point of the exterior air so there is no condensation. Additionally, higher quality insulated curtain walls will use insulating materials treated with an anti-microbial agent to prevent mold or mildew should moisture manage to migrate inside the curtain through a tear or scrape. Finally, the reduced heat transfer across the insulated curtain wall allows the mechanical chilling equipment to operate using less energy.

Maintaining a High Humidity Space

The principles are the same in the case of maintaining a high humidity space, at least from the barrier standpoint. While a mechanical chiller is not used, some source of moisture is, whether it be misting sprinklers or the addition of high humidity air flow into the space. Once again, the vinyl coated fabric covering the insulation is an effective way to keep the moisture and moist air inside the space, without concerns about mold or mildew on the curtain walls themselves. While inhibiting heat transfer is less important, the insulated curtain wall still plays a role — maintaining temperature to reduce temperature (and therefore humidity) fluctuations.

Find the Right Temperature with HVLS Fans and Curtain Walls

Achieving proper temperature and humidity control is an essential part of food manufacturing and storage. HVLS fans can help cool workers during hot summer days and destratify air during cold ones, while curtain walls provide an excellent insulated barrier for temperature and humidity control within partitioned spaces.

Facility managers willing to invest in products like HVLS fans and curtain walls are likely going to see many qualitative benefits right away (increased worker comfort and productivity) and quantitative benefits down the line (ROI through energy savings and food quality).