Workshops

The ventilation system is the lifeblood of any laboratory building. It can also be extremely energy-intensive if not properly implemented. The exhaust side of the ventilation system is critical to maintaining a safe and healthy work environment and can be comprised of numerous interacting components, from the exposure control devices such as fume hoods to the airflow controls and exhaust fan and stack. The exhaust system alone can be responsible for 30 percent of the laboratory’s total energy consumption and often drives the demand for replacement air resulting in the ventilation systems, accounting for more than 60 percent of total building energy consumption. Proper selection, design, and operation of the lab exhaust system from hood to stack is critical to occupant safety, energy efficiency, and sustainability. Minimizing the carbon footprint and decarbonizing labs are impossible without addressing the lab exhaust system.

Proper design of lab exhaust systems requires understanding the occupant’s demand for ventilation, selecting appropriate exposure control devices, determining minimum require airflow specifications, control of airflow, and proper transport and discharge of potentially dangerous exhaust from the system. Below the ceiling, if the exhaust system is not properly designed, occupant safety can be jeopardized through increased exposure to airborne hazards not properly captured and removed from the building. Above the roof, the improper design and operation of the exhaust system can also result in adverse re-entrainment of the contaminated exhaust back into the laboratory or neighboring building. Proper exhaust is critical to providing safe and healthy environments for people working in, on, or around a lab building. On the other hand, lab exhaust systems that are over-designed can lead to high capital costs and excessive ongoing energy consumption and maintenance burden.

This workshop will offer new advancements in designing safe and energy-efficient laboratory exhaust systems, including:

• Evaluation of lab ventilation risk and occupant demand for ventilation; 

• Selection and specifications for various types of common exposure control devices (ECDs);

• Establishing appropriate airflow specifications for air change rates, contaminant transport and exhaust discharge;

• Best practice design guidelines for exhaust stack and air intake placement;

• Determining the best dispersion model for predicting concentrations at the nearby air intake to be used for specific applications; and

• Control strategies that can be used, in part or in whole, during the design of a new laboratory or the renovation of an existing laboratory.

These strategies can safely reduce the energy consumption of the lab exhaust system by about 50 percent compared to a typical constant volume system, which equates to approximately 15 to 30 percent reduction in the laboratory's total electrical energy use. The workshop will include examples of case studies that demonstrate how these design strategies should be implemented. Special attention will be made that address specific requirements called out in the existing California Title 24 Energy Code as well as discussions of proposed changes in the upcoming 2025 edition.

• Upon completion of this workshop, attendees should be able to:

• Be familiar with lab ventilation risk and methods to establish appropriate airflow specifications.

• Understand different types of ECDs and airflow control systems.

• Evaluate the best airflow control and exhaust strategy for their application.

• Be familiar with plume dispersion principles, which will aid in understanding the optimum placement of exhaust fans and air intakes to minimize fan energy requirements.

• Select the appropriate method for evaluating the air quality versus fan energy savings.

• Identify which exhaust systems can provide the most energy savings and the best return on investment.