Laboratory Design Newsletter 2012 Selected Abstract

Information Tools for Long-Term Sustainability in Laboratories

Jim Coogan and Paul Jablonski, Siemens Building Technologies

Abstract

The concept of sustainability takes a long view of operations and their impacts. It's not a design philosophy, but a commitment to manage environmental impact over the long term.

Long-term management of environmental impact has at least three components:

  • Maintain function of the systems
  • Maintain performance of systems
  • Improve operation over time

A working system degrades over time unless you pay attention. This means measuring performance, identifying faults, and correcting them. This all depends on having the right information, because "you can't manage what you don't measure!"

A laboratory ventilation reporting package takes data from the building automation system (BAS) to deliver information to support these objectives throughout the life of the system. It informs managers on effective function in terms of safety and comfort measures. It also documents actual flow rates in relation to predicted or "design" usage. All of this information is presented primarily as rolled-up summaries designed to highlight the problems. An example of such a report is shown in Figure 1. The supporting, detailed data are available for further inspection.

Photo 1

Figure 1. Room performance comparison identifying deficiencies.

If the data show that the system functions properly, then begin looking for ways to improve performance. The Labs 21 Tool Kit offers a wide menu of strategies and measures that might help, but how do you choose which ones will make a difference for your facility?

The answer is in the air flow drivers for the room, which are energy drivers. Three drivers for a chemistry laboratory are well-known:

  • Dilution ventilation or "air change rate"
  • Exhaust devices
  • Thermal load

At any moment, one driver sets the flow rate for a given room. The laboratory room driver report in Figure 2 helps choose the correct improvement strategy for your site. It analyzes air flow data over time and attributes a percentage of the total air flow to each driver.

Photo 2

Figure 2. Laboratory airflow driver report showing ventilation rates.

If the exhaust devices are the main driver, further analysis identifies the most effective measures.

  • Are the hoods used regularly? Consider decommissioning some exhaust devices.
  • Are the hoods using air because they are left open? If so, sash management programs or automatic sash closers make sense.
  • Are the hoods driving the air flow even when they are closed? This is the case that warrants re-evaluating the minimum flow rate in light of current guidelines.

If the base ventilation drives air flow, consider:

  • Evaluate the dilution flow (air changes per hour) in light of current industry trends. Lower rates may be justifiable.
  • Implement unoccupied ventilation.
  • Apply contaminant sensors to vary ventilation rate according to actual load.

If the cooling drives the air flow rate, then look for ways to reduce the load:

  • Relocate heat sources.
  • Reduce lighting.

Each option requires careful discussion with laboratory workers, environmental health and safety professionals, and facilities staff. The air flow driver report and other air flow details bring facts to those discussions and eliminate guesswork.

The report in Figure 2 shows that dilution drives 90 percent of the airflow to this laboratory. This report suggests that a re-evaluation of the minimum airflow is in order.

In conclusion, real sustainability is a long-term concept. It requires ongoing management, which in turn requires information in a form that supports action. A good BAS data collection and reporting package will help you identify the measures that will lead to the most efficient system operation and long-term sustainability.

Biography

James Coogan is a principal in product development and applications at Siemens Building Technologies. With more than 30 years designing microprocessor-based controls for mechanical systems, he has contributed products ranging from simple room controllers to Internet-based operator interfaces, resulting in several patents. Mr. Coogan has chaired several ASHRAE Committees, including Controls, Laboratory Systems, and Plant and Animal Environments. Mr. Coogan is a member of the American Industrial Hygiene Association committee that revised the Z9.5 Standard: Laboratory Ventilation. Mr. Coogan participates in various programs for Labs21. His publications include technical papers on room pressurization and laboratory system commissioning. Mr. Coogan earned his bachelor's degree in mechanical engineering at the Massachusetts Institute of Technology.