In the first blog post of this series, we established the importance of measurement for optimum HVAC performance in a food manufacturing facility. Without measurement, it is impossible to approach the next concept: Control integration. Analysis is where we begin to understand how supply air and exhaust fans are actually operating. They may be running independently, or simply on temperature set point and time clock functions for start/stop, but to really gain control over a building’s HVAC system the components need to operate together. Just as there is no “I” in team, so it goes with how and where air should be designed to move throughout a plant.
Used as a verb, integrate is defined as “to combine into one unified system.” When we talk about HVAC control, this should be applied to pairing equipment operation with an overall goal of positive pressurization. Beginning with where raw materials are received, to the manufacturing process itself, and ultimately to the final, packaged product, an integrated control system can eliminate many of the possible conflicts present when constant human intervention is necessary. Think cruise control for HVAC.
This integration of controls using standard PLC logic-based devices, pressure differential measurement, temperature and humidity set point, and variable speed frequency drives allows an HVAC system to operate virtually hands-free with the exception of routine maintenance. Having an airflow set to operate by design without continuous input from the plant engineering department shifts the focus where it should be: on the product manufacturing process. Well, hello… let’s make some more product with all this extra time we have!
As with many things, there is more than one way to approach HVAC control integration. The key is to select a method that is flexible – one that meets short-term needs, but can also respond in a user-friendly way to changes in plant, product, or operations. A well-devised control system will automatically maintain differential pressure in food safety zones, operate HVAC equipment in concert with the manufacturing process, and save energy in the long run. When you realize that the “I” you wanted all along is needed for WIN, you’ll wonder why you didn’t integrate sooner.
ERP’s Key Concepts Related to Control Integration
First: We actually begin at the end – with packaging – and work our way backwards. The reason we do this is to use the final product as the barometer, then consider how pressurization affects every part of the process leading to that point.
Second: From doors opening and closing to stops and starts in the process, everything contributes to airflow and pressurization. Performing an inventory of each aspect allows for complete and seamless integration of all HVAC intake and exhaust components.
The Food Manufacturing Trifecta: Three Things You Don’t Want to Overlook is a three-part blog series focused on key areas that should always be considered when addressing quality control within a food manufacturing environment. Be sure to read #1: HVAC Measurement, and #3: HVAC Customization for a complete look at creating an ideal airflow system.