Mold concerns became highlighted in the 1920s, when commercial and military needs for safe storage and transport of supplies focused attention on preventing biological deterioration of materials. To prevent this, basic conditions that had been used for decades as guides for food storage in small, agrarian communities (damp: bad for grains, good for root vegetables) were applied to warehouse construction and management with the expectation of preserving high material values. When mechanical control of indoor climates linked temperature and humidity requirements to energy consumption, tighter setpoint values were adapted from these early food preservation practices.