Industry leaders realized hundreds of years ago that their processes and machines operate best when the indoor relative humidity is maintained at an optimum level for their process. They found it was necessary to use energy to increase productivity, lower scrap and environment impacts, maintain profits, and maintain costs to their customer. It does not matter if their process is related to food, woodworking, textiles, printing, pharmaceuticals, electronics, automotive, laboratories, or maintaining and preserving artifacts in museums and libraries. Controlling the indoor humidity was and is still critical for their applications.
One of the main reasons for the development of modern HVAC equipment was to maintain control of indoor relative humidity. The ASHRAE Handbooks as well as individual industry-specific manuals have a wealth of information on the recommended levels of relative humidity that should be maintained to assure preservation, productivity, and profitability.