ASHRAE “Classification of Laboratory Ventilation Design Levels” recommends continuous monitoring of laboratory pressure in LVDL-4 rooms.

By Ryan Thompson, TSI Applications Engineer

Recently, ASHRAE released the “Classification of Laboratory Ventilation Design Levels” paper. This is meant as a tool for Engineers and Laboratory Owners to assess the risks in a specific lab, and gives requirements for design and operation of the HVAC system. 

The paper breaks labs down into 5 categories of Laboratory Ventilation Design Levels (LVDL), from level 0 to level 4, where LVDL-0 is a low risk space like a high school lab, and a LVDL-4 is high risk spaces like an Organic Lab, or Chemical Development lab.

For the higher risk labs in the LVDL-4 category, ASHRAE recommends the laboratory “Provide continuous monitoring of laboratory differential pressure.” What does this mean? It means offset control is not good enough in critical spaces. At a minimum, offset control with pressure monitoring is required. 

With the TSI Laboratory Room Controller, or LRC, you can easily do Offset Control with Pressure Monitoring. Or, take it one step safer, and utilize the differential pressure measurement to help control your offset with Adaptive Offset Control.

Types of LVDL-4 laboratories:

• Chemical development laboratories
• Polymer synthesis laboratories
• Organic/inorganic chemical synthesis laboratories
• Special high-hazard research laboratories

For your Typical Research Laboratories (LDVL-3), ASHRAE recommends the lab “should consider monitoring laboratory pressure differential.” Just doing offset control may not adequate, and monitoring the pressure differential is the recommended control strategy. Again, the TSI LRC can easily accomplish this, as well as provide additional levels of safety utilizing Adaptive Offset Control.