(734) 327 4079 info@ansight.com
AnSight’s Solutions for COVID-19

Laboratory Ventilation

May 30, 2020 | Blogs | 0 comments

The purpose of laboratory ventiliation systems is to minimize the risk of chemical exposure and fire hazard, as well as facilitate odor removal by reducing the contaminant concentration to safe level while simultaneously maintaining thermally acceptable environment for occupants. Often high airflow rates specified in terms of air change rates per hour (ACH) are perceived to minimize such risks. Although high airflow rates can reduce the overall concentration of contaminants, it may not ensure low levels of contaminant concentrations at all locations in a lab space, including the breathing zone of occupants which can potentially increase risk of chemical exposure. Our recent Computational Fluid Dynamics (CFD) analysis investigated the impact of supply airflow rates ranging from 4 to 12 ACH on the uniformity of contaminant concentration in a three dimensional lab space. This study indicates with increasing ACH the overall average concentration levels in the space decreases. However, the average concentration at breathing zone level was 26 percent higher than the expected diluted (target) concentrations at each ACH level whereas the maximum concentration was about 5 times higher than respective target concentrations. Furthermore, the flow path of the contaminants remains almost similar at all ACH levels, and thus, ACH has a little impact on the flow path of contaminants, which in turn affects the distribution of contaminants. For the case analyzed in this study the concentration levels at a breathing zone level were significantly reduced, even at low supply air flow rates, by modifying the location of air return from high ceiling level to a low level wall return. The flow path of contaminants and resulting distribution of contaminants in the lab space primarily depend on the HVAC configuration. Strategic design of HVAC configuration and optimization of the locations of air supply and return can be valuable in reducing the supply airflow rates and increasing ventilation effectiveness.

About the author

Dr. Kishor Khankari

ASHRAE Fellow, ASHRAE Distinguished Lecturer

Dr Kishor Khankari is the founder of AnSight LLC. As a specialist in Computational Fluid Dynamics (CFD), his passion for solving engineering problems and providing sound scientific solutions has led to innovations and optimized designs in the industry.

A noted expert in his field, he has a Ph.D. from the University of Minnesota and has published in several technical journals and trade magazines. As a well sought-after speaker Dr. Khankari makes regular presentations in various technical conferences and professional meetings worldwide.

Recent Posts

Ventilation Guidance for Residential Kitchen with Gas Stove

Recently the residential gas stoves were in the News due to the generation of pollutants during their operation. Cooking activities as well as the combustion of natural gas through gas stove burners produce several indoor pollutants. Exhausting these pollutants from...

CFD Analysis of Residential Kitchen Ventilation with Gas Stove

Proper ventilation of the kitchen is essential to reduce the occupant exposure to various pollutants generated during the cooking and the combustion of natural gas through the gas stove burners. Several parameters related to the design and operation can affect the...

CFD Analysis of Demand Control Ventilation for Laboratories

What is Demand Control Ventilation (DCV)? Often high air change rates per hour (ACH) are specified for laboratories to meet the goal of ventilation. The ACH numbers specified are mostly consensuses based on simplistic approaches of perfect mixing of contaminants with...

CFD Analysis Evaluates Efficacy of Reactive Air Cleaning Technology

What is reactive air cleaning? Reactive air cleaning involves the release of reactive agents in the room to actively mitigate airborne pathogens and other pollutants. Unlike traditional dilution ventilation in which the concentration of the airborne pathogens in the...

Share This