The CRF4 Cleanroom Fogger uses 35 ultrasonic piezo devices to generate 1.25 cubic meters of pure fog per minute with 187 ml of fog density per minute to provide 10-15 feet of visible air flow for smoke studies and air flow characterization in clean rooms, sterile rooms, medical operating rooms and ISO suites. The CRF4 fog volume competes with LN2 foggers for fog volume performance. But the CRF4 does not use liquid nitrogen, requiring only DI Water or WFI water to produce this higher volume of fog, adding adjustable fog volume, adjustable airflow, and wireless remote control. The CRF4 operates for about 45 minutes at maximum fog volume or up to 90 minutes at lower fog volumes. The CRF4 supports USP 797 In-situ Airflow Analysis; USP 800 Compound Pharmacy airflow tests; Airflow Recovery Tests guided by ISO 14644-3, Annex B12; Airflow Visualization Tests guided by ISO 14644-3 Annex B7; airflow tests for NSF 49 and Bio-Safety Cabinets; and airflow requirements using Semiconductor Clean Room Guidelines, Federal Standard 209E.