Engineered controls, like fume hoods, are an integral part of most laboratory facility planning. Fume hoods have a significant impact on building infrastructure, are energy-intensive, and basically, remove conditioned air from the building. The extracted air then needs to be brought back into the building for the HVAC to adequately balance temperature, humidity, and pressure. Ducted fume hoods impact the building’s need for larger air handlers, boilers, chillers, cooling towers, and exhaust fans due to the amount of air that needs to be processed.
Studies have calculated that laboratories consume five to 10 times more energy per square foot than conventional office buildings. How can we address these problems while achieving carbon neutrality?
Alternative engineered control systems, including ductless filtering fume hoods, are one answer.
When a lab is designed with ductless fume hoods as the primary engineered control system, the impact includes carbon reduction. As we aim for carbon neutrality by 2030, the ductless fume hood plays a significant role in achieving this goal. Obvious savings can be found in reducing peak exhaust output, but that reduced exhaust air output allows buildings to achieve much more. Let’s look at the impact of replacing ducted fume hoods with ductless fume hoods in a real-world example: Bristol Community College of Massachusetts.
Fume hoods and containment devices should be designed with safety as the priority.
The Bristol high-performance laboratory was originally designed to include 22 ducted fume hoods, which had a combined intake and exhaust of 70,000 cubic feet per minute (CFM). It required three air-handling units (AHU), one with run-around loop heat recovery and one with enthalpy wheel energy recovery. The proposed redesign replaced that equipment with:
- 13 filtered hoods
- Four ducted hoods
- CFM: 24,000 intake and exhaust
- Two AHUs
- Enthalpy wheel recovery
Along with the air reductions, the redesign included a combination of ground- and air-source heat pumps, enthalpy heat recovery wheels, fan coil units, centralized indoor air quality monitoring, and natural ventilation. It reduced mechanical, electrical, and plumbing (MEP) to just 14 percent of the gross square footage. Additionally, the photovoltaic (PV) arrays, half of which would have supplied the 22 ducted hoods, are now used to recover energy.
A holistic approach to safety
Fume hoods and containment devices should be designed with safety as the priority. When considering ductless fume hoods, chemical handling needs must be assessed to determine whether they are suitable for filtration. If so, a filter life cycle must be proposed based on analysis using AFNOR NF X 15 211, ANSI z9.5-2022, CSA Z316.5-2020, and NFPA 45-2023 edition standards.
Under normal operating conditions, a ductless fume hood must also be able to guarantee user protection with assurance that release will never exceed one percent of the TLV past the filter exhaust. After this, the hood must also perform during two additional operating phases: detection and safety with each phase guaranteeing a level of protection as per the AFNOR NF X 15 211 standard.
One misconception about ductless fume hoods is that they can be used for only small amounts of chemicals or only for odor mitigation. In reality, some ductless fume hoods are approved for the majority of pharmaceutical, organic chemistry, agriculture and flavor and fragrance applications, among others.
Safety does not stop with the fume hood but continues throughout the chemical life cycle. Proper controls must be in place to protect the breathing zones of people working in the lab. These are achieved through a combination of filtering storage, whole room air filtration, integrated filtration packs for safety cabinets, and filtering fume hoods.
The various safety aspects should be monitored: face velocity, filtration efficiency, and ambient air pollution. Continuous monitoring provides critical safety metrics and helps establish more effective lab safety protocols.
Safety does not stop with the fume hood but continues throughout the chemical life cycle.
Embracing new technologies
While we may be reluctant to change, we must consider what’s best for the environment. Embracing new technologies can have a significant impact on the future. As we increase our understanding of the impact of our actions, we can make changes to improve safety and product performance.
Ductless filtering fume hoods can improve lab design efficiency and increase your flexibility as your lab changes and grows. Filtration protects you wherever chemicals exist and supports your facility’s efforts to reduce its carbon footprint.