Improving Lab Ventilation System Efficiency
Lab managers can reduce their energy impact by improving their facility’s ventilation system and practicing better ventilation management
According to the International Institute for Sustainable Laboratories, labs typically have five to 10 times the energy and carbon footprint of a comparatively sized office building—largely due to the amount of outside air that is required to properly run these facilities. In fact, ventilation systems account for almost half (44 percent) of energy consumption in labs.1 However, lab managers can reduce their energy impact by improving their facility’s ventilation system and practicing better ventilation management.
Ellen Sweet, laboratory ventilation specialist at Cornell University’s Department of Environmental Health and Safety, encourages lab staffs to develop a laboratory ventilation management plan (LVMP), which provides guidance for balancing the safety value of ventilation with the financial and carbon costs associated with the energy required to supply air in the lab. The LVMP at Cornell is the result of a working partnership between the university’s lab workers and administration; the Facilities Services’ Energy and Sustainability department; and Environmental Health and Safety. Cornell implemented its LVMP as a way to help the campus achieve its goal of becoming climate-neutral by 2035. Within the plan, a list of responsibilities is broken down by individuals or groups in charge of carrying out these duties. By assigning everyone a role, the campus can better track its energy consumption, identify areas of improvement, and determine whether any infrastructure needs to be updated. Sweet also notes that having trained control technicians who can recognize when mechanical equipment needs repair or recalibration is equally important.
Demand control ventilation
As the number of automated and smart labs continues to grow, more labs are adopting the use of modern demand control ventilation (DCV) systems, like Aircuity’s 2.0 Platform, which has been available since 2017. The system provides a comprehensive dashboard and analytic interface where users can track laboratory energy usage, lab air change rates, fume hood sash management, total volatile organic compound (TVOC) and particle events, and other parameters.
With DCV, the volume of outside air brought into the building increases and decreases as the indoor levels of carbon dioxide generated by people within the building rises above or falls below the ambient outdoor levels of carbon dioxide. Previously, traditional DCV systems required multiple sensors be deployed throughout a facility—a factor that Peter Hmelyar of Aircuity (Newton, MA) cites as a major pain point because they require significant upkeep and can lead to inaccuracies. “The biggest challenge is that at least three expensive sensors (two for TVOCs and one for particles) are required in each lab to measure for potential contaminants, which could lead to hundreds of sensors to monitor and maintain,” says Hmelyar. To help solve this, Aircuity uses centralized sensors in a sensor suite that can monitor up to 30 lab spaces, which significantly reduces the number of sensors needed and leads to lower life-cycle costs.
It’s all in the numbers
Even if your lab isn’t outfitted with an intelligent, continuous air monitoring system, there are still ways to reduce energy consumption. As David Bearg, principal scientist at Life Energy Associates (Concord, MA) says, “You can’t effectively manage what you can’t measure.” Lab managers should periodically evaluate the actual performance of their ventilation systems for a variety of reasons. Bearg identifies a few:
- If more ventilation is being provided than intended, then energy will be wasted in conditioning and moving this excess air against what can be considerable pressure drops.
- The design calculations used for setting up the amount of ventilation may miscalculate the effective volume in the laboratory space, and thereby lead to an incorrect amount of ventilation.
- Ventilation performance can change over time as the HVAC system attempts to dynamically respond to changes in filter pressure drop.
To address these variables, Bearg suggests using measurement and verification (M&V) testing to document that the HVAC system is performing as intended. As mentioned above, accurately calculating your lab’s air changes per hour (ACH) rate is another important step in ensuring you’re running your lab efficiently. Historically, ACH rates have varied from as low as 4 to as high as 12 ACH depending on the type of lab. ACH rates have commonly been based on calculations of room volume under empty, unoccupied conditions. But in reality, labs are equipped with instruments, supplies, and furnishings that can reduce open-air volumes by as much as 15-20 percent.2 “Before pursuing the complexity of continuous monitoring in the lab environment, an important first step in improved lab management would be the documentation of the actual ACH rate being provided. Not only is this determination an important building management tool, it should be included as part of commissioning as well as being a periodic check on ventilation performance,” explains Bearg.
Related Article: Managing Indoor Air Quality
If you’re looking to install a new ventilation system or make improvements to an existing one, Bearg says one factor to consider is where the supply air enters the laboratory in relation to any exhaust hoods. “Poorly designed labs can have turbulence near the face of the fume hood, leading to reduced capture and containment,” he says.
Regardless of whether you outfit your lab with a smart ventilation system for continuous monitoring or conduct periodic checks of your lab’s airflow, staying on top of ACH rates and overall energy consumption is key to running an environmentally friendly facility. As the saying goes, “knowledge is power,” and the more you understand how your lab runs, the more efficiently you can manage energy consumption and costs. This philosophy will only become more crucial as lab ventilation systems continue to evolve to become “greener” in the future. “Going forward, information capabilities will continue to expand. I believe all the data gathered about the operation in the lab—including ventilation, fume hood operations, and other parameters—will [provide] lab managers, researchers, health and safety professionals, and building managers with more and better information to operate and safely occupy laboratories,” says Hmelyar.
A success story
The Wistar Institute (Philadelphia, PA), which specializes in oncology, immunology, infectious disease, and vaccine research, was looking to reduce energy use while enhancing the facility for its occupants. Wistar connected with Aircuity to implement the company’s smart ventilation platform into lab and vivarium areas. A turnkey system was installed at the institute as an overlay to the existing system. Aircuity’s demand control ventilation platform now monitors the spaces for volatile organic compounds, carbon dioxide, particulates, and relative humidity, and uses the information gathered to optimize ventilation rates within the spaces. According to a case study provided by Aircuity, the Wistar Institute is now saving $89,000 per year with the new system.
1. https://www.fenner-esler.com/blog/balancing-standards-forlab- ventilation-with-energy-efficiency-strategies/
2. “Laboratory air quality and room ventilation rates” by Robert Klein, Cathleen King, and Anthony Kosior, the Journal of Chemical Health & Safety, September/October 2009