Cork Institute of Technology 3rd March 2020
ASHRAE’s March event in Cork saw a visit by Chris Mulholland and Phil Milne-Smith of Critical Airflow Europe Ltd, specialists in laboratory airflow control systems.
Phil provided the context for ventilation control, balancing energy usage against good containment (up to 70% of a laboratory building energy usage could be attributed to HVAC). Ventilation drivers were assessed such as air changes, room pressurisation, fume cupboards and exhaust stacks and the ASHRAE Laboratory ventilation design level categories were discussed in detail.
The concept of demand-based ventilation control, matching air changes to lab occupancy and to VOC and particulate emissions from lab operations and events (e.g. spillage) was presented as an opportunity to realise significant energy savings while promoting a safe environment within the lab.
Supply-side and extract-side ventilation requirements were then discussed in more detail including types of fume cupboard and their effect on room ventilation and pressure cascades, thermal comfort and effect of variable equipment heat gains.
Finally, the extract system was examined in detail highlighting the ASHRAE guidance regarding calculation of dilution and plume geometry to prevent re-entrainment. The benefits and applications of a manifolded extract system was discussed and the components, such as VAV dampers, within the HVAC system together with control strategies was discussed further.
A lively Q&A session rounded off a very informative evening.