Manufacturing plants are designed based on the requirements for the products being manufactured, which in many cases are very specific. Typical requirements may be:
High and low temperature depending on the product
High and low humidity requirements depending on the product
High volume of air (air changes per hour) depending on the operation
Large quantities of outdoor air requirements.
All of these requirements are unique to specific products for the pharmaceutical industry, food industry, petrochemical plants, etc. Such stringent requirements are not needed for normal commercial structures. Unlike HVAC systems for commercial structures, which are designed based on occupant comfort and code compliance, HVAC systems for manufacturing structures are designed based on the product requirements.
There are several factors that impact the HVAC design for what are normally consider to be large, wide-open spaces. These factors include pressurization, humidity control, and dust control. With lots of different point-of-use exhaust systems, dust control can be provided, but this can have an undesired impact on pressurization. If there are processes that rely on tight humidity control, pressurization is even more important to consider. Of course, encapsulation of any area with humidity control is key—and don’t forget to manage airflow through the entrance/exit points.
Higher-quality filtered air, increased control of humidity, greater requirement for once-through air versus recycled, and pressurization differences between spaces to control for airborne contaminants.