Steps to minimize mold risk after prolonged shutdown
Keep indoor humidity as low as possible, no more than 50%, as measured by a hygrometer. Building managers may consider continuous indoor humidity monitoring with a digital hygrometer, preferably more than once a day, to minimize the need to enter the building. After a longer shutdown and before the residents return, buildings must be checked for mold and excessive moisture. After an assessment confirms that mold and moisture are not detectable, OR after remediation is complete, a building's HVAC system that is inactive during an extended shutdown must be shut down for at least 48 to 72 hours (known as a "flush-out period"). be abused before the inhabitants return. After the building is opened and occupied, routine (e.g., weekly) inspections of the HVAC system are recommended to ensure efficient operation. If a routine HVAC operation and maintenance program does not exist for the building, one must be created and implemented.