ASHRAE's "Classification of Laboratory Ventilation Design Levels" provides guidelines for assessing risks in laboratories and specifies HVAC system design and operational requirements. The classification divides labs into five levels (LVDL-0 to LVDL-4), with LVDL-0 being low-risk spaces like high school labs, and LVDL-4 covering high-risk spaces such as chemical or organic labs.
For higher-risk laboratories in the LVDL-4 category, ASHRAE advises continuous monitoring of laboratory differential pressure. This means that relying solely on offset control may not be sufficient in critical environments; instead, offset control combined with pressure monitoring is the recommended approach. Tools like the TSI Laboratory Room Controller (LRC) can perform this function, and advanced options like Adaptive Offset Control can enhance safety further by using pressure measurements to refine offset control.
For typical research laboratories classified as LVDL-3, ASHRAE suggests monitoring pressure differentials in addition to offset control. This provides added protection by ensuring the lab operates within the proper safety parameters, and the TSI LRC can support both pressure monitoring and adaptive control strategies for increased safety.
These recommendations help ensure that laboratories, especially those with higher risks, maintain proper environmental controls to protect both researchers and the integrity of experiments.