Recirculatory cleanroom airflow system filter air through a dedicated air handling system specifically designed and engineered to maintain the cleanroom at the required operating environment tolerance. Recirculating airflow systems offer temperature relative humidity and pressurization control through an interface on the air handling unit itself. These systems are typically paired with static filtration modules instead of fan-powered modules. Unidirectional airflow inside a recirculating cleanroom can be achieved via the placement of HEPA filter modules and low-level return, which direct airflow and heat load removal in areas of the cleanroom environment that require higher airflow. In some cases, lower ISO class recirculating clean room can also be filtered via HEPA units in line with the supply air from the HVAC system rather than ceiling modules. This reduces the cost of maintenance requirements in the future.