Field certification consists of required tests related to containment (personnel, product and environmental protection), and optional tests related to worker comfort and safety.
Required tests include:
- Airflow velocity profiles (downflow and inflow)*
- Airflow smoke patterns*
- HEPA/ULPA filter leak test*
- Site installation assessment tests*
- Alarm functions*
- Blower interlock*
- Exhaust system performance* (proper exhaust duct negative pressure and canopy performance)
- Cabinet integrity test (positive plenum cabinets only)
Worker comfort and safety tests include:
- Lighting intensity*
- Noise level*
- Electrical leakage, ground circuit resistance*, and polarity*
*Part of LTS Standard Certification Report
In addition to the above NSF/ANSI 49 recommends the lifespan of a unit be 15 years. Starting at age 16 Lewis Testing Services requires a degradation inspection be performed to reduce the safety risks that an aging unit generates.