Sustainable "Green" Forensic Laboratory Design
Everyday the U.S. population is faced with the vast issue of energy reliability and availability. Those who were affected by the “Blackout of 2003,” know first hand the value of our natural resources. The absence of electricity and water dramatically impacts every aspect of our lives. For that reason, protectingand conserving our natural resources should be taken seriously.
Laboratories are one of society’s major energy users and consumers of natural resources, but that can be moderated by incorporating several different design strategies. Within the forensic industry, we refer to sustainable, or “green,” design to create laboratories that will endure the test of time and save energy.
Sustainable design provides facility users with a comfortable, safe, healthy, and productive environment while supporting a building infrastructure that enables the forensic laboratory functions to be energy efficient. These energy efficient laboratories meet the needs of today, without sacrificing future needs.
Forensic laboratories consume considerable resources during various criminal investigations, making sustainable design a challenge in these facilities. To overcome the obstacles that diminish our natural resources, new forensic laboratory projects incorporate several sustainable design strategies. Many facilities also seek U.S. Green Building Council Leadership in Energy and Environmental Design (LEED™) Certification. Fortunately, there are two excellent resources available to help designers and owners achieve their goals.
The first is LEED,™ The Leadership in Energy and Environmental Design initiative, sponsored by the U.S. Green Building Council. This is a voluntary, consensus-based national standard for developing high performance sustainable buildings. The members of the U.S. Green Building Council that developed LEED™ represent all facets of the building industry and are continuously updating the standard. LEED™ standards are available not only for new construction and major renovations, but for existing building and commercial interior projects. Additional information on LEED™ is available at www.usgbc.org.
The second resource is the Environmental Performance Criteria for Laboratories (EPC), jointly sponsored by the U.S. Environmental Protection Agency (EPA) and Department of Energy (DOE). EPC is an extension of the LEED™ rating system, but focused on laboratory projects. EPC requirements are over and above LEED™ because the environmental impact of laboratories is much greater than that of an average building. Currently there is not a formal accreditation process for the EPC. Additional information is available at www.epa.gov/labs21century
Pressure mapping effectively separates non-lab space from the constant 100%outside air requirements of lab space to minimize HVAC loads.
Strategies for Sustainability
After reviewing various LEED™ and EPC resources, many design approaches and strategies will be apparent. When evaluating your laboratory’s specific sustainable design strategies, we recommend only seeking those that will help conserve natural resources without compromising performance, safety, and reliability. This article focuses on strategies that can be incorporated without a significant negative impact to the project’s schedule, budget, and design intent.
Human-centered design and full energy and daylighting simulation are strategies that can help create a superior quality work environment, andat the same time, significantly reduce the total energy cost.
The Philadelphia Forensic Science Laboratory takes advantage of the inherent high ratio of glass at the exterior wall combined with ceiling geometries, solar control, and high-reflectance interior finishes to achieve dramatic, diffused deep daylighting. Lighting fixtures are installed parallel to the exterior wall to allow lighting controls to automatically de-energize perimeter zone fixtures when required lighting levels are achieved naturally.
Encourage facility users to use alternative transportation. Locate the forensiclaboratory in close proximity to public transportation. Offer bicycle storage and locker room facilities with showers. Provide preferred parking for those that carpool and refueling stations for alternative fuel vehicles. Refueling stations can be shared among neighboring facilities to help offset the initial cost. If the facility uses an on-site fleet, considerusing alternative fuel vehicles, in lieu of gasoline.
A big part of water conservation deals with reducing potable water use. The first step to reducing potable water in landscape irrigation is to choose landscape materials and plantings that inherently require less water. Consider using captured rainwater, recycled gray water, or eliminating a permanent site irrigation system. Use low flow plumbing fixtures or waterless urinalswithin the building sewage system.
Potable water use can also be limited within the laboratory areas. First, avoid open loop cooling systems. This is where water is used then directly discharged to the drain. Instead use a closed loop systems where water is conditioned and re-circulated to minimize wastewater. Second, only provide hot water at the sinks, benches, and fume hoods when needed.
Energy and Atmosphere
First and foremost, design the forensic laboratory to comply with the AmericanSociety of Heating, Refrigerating, and Air Conditioning (ASHRAE) 90.1 energy standard. A number of states have already adopted this as their state energy code. Energy recovery is another strategy that is often viable for forensic laboratories. For example, capture heat from the lab exhaust and use it to preheat fresh (outside) air or capture waste heat from a condenser water system and use it for domestic hot water heating.
Pay particular attention to part-load system efficiency. Since not all forensic laboratory systems function simultaneously, the building systems operate in a part-load condition most of the time. We select equipment with maximum efficiency at this part-load condition so that we can better capitalize on the benefits of higher operating efficiencies. When possible, use EPA Energy Star compliant forensic laboratory equipment. Further, we “right size” mechanical and electrical equipment by avoiding oversized systems and excessive safetyfactors.
One of the keys to superior forensic laboratory performance is commissioning. Include a commissioning agent as part of the design and construction team to verify that the building is designed, constructed, and functions in accordance with the owner’s requirements. Many times energy reductions are not achieved because of the lack of a comprehensive commissioning program. For example, a control valve that is not calibrated properly may still function well enough for the system to operate without a “fault” alarm. However, the system will never achieve the level of operating efficiency expected and will unnecessarily waste energy.
Health and Safety
Consider variable volume supply and exhaust air systems, which allow you to reduce air volumes during unoccupied hours. Keep in mind that variable volume systems are not appropriate for all forensic laboratories. When airflow is driven by minimum air change rates (rather than cooling load or fume hood makeup air requirements), it may not be possible to reduce airflow. In thesecases, constant volume systems should be considered.
It is also important to evaluate forensic laboratory fume hood requirements and reduce the quantity and size when possible. Snorkels and re-circulated cabinets are excellent ways to provide local exhaust (with lower airflow rates) and often result in a more effective exhaust system because of the proximity to the source of contamination.
Indoor Environmental Quality
Design the laboratory to comply with the ASHRAE 62 standard for ventilation and indoor air quality. This standard primarily pertains to non-laboratory spaces. Remember that the forensic laboratory operation and maintenance staff will spend a considerable amount of time in these areas.
Also, consider demand based ventilation control via carbon dioxide (CO2 ) monitoring. This enables the optimization of outside air intake based on actual building occupancy rather than speculative values. In the right circumstances, CO2 can be an excellent indicator of occupancy.
Specify low volatile organic compound (VOC) construction materials, to reduce irritating or harmful effects of residual VOC emissions. This would include materials such as sealants, adhesives, paint, and carpet. A post construction (pre-occupancy) two-week flush prepares the building for occupancy by removing any unavoidable VOCsfrom new building materials and/or construction debris.
Planning and Design
Minimize critical environment areas such as hazardous storage, spaces requiring specific environmental control, and areas with unique noise and vibration requirements. These types of areas require dedicated support systems andare square foot dependent. Meaning, as these spaces become larger, the supportingbuilding systems also become larger, using more energy.
Displacement ventilation is a heating, ventilating, and air conditioning (HVAC) strategy where supply air is introduced at low pressure through grilles at floor level. The air is displaced in the breathing zone. As it is pushed up, it is removed at ceiling level. Displacement ventilation should be evaluated as a viable alternative because it can be a very low energy high indoor air quality system.
Forensic laboratories are always changing. Design for flexibility. Changes may even come up before the original design is completed. Infrastructure systems should be readily expandable. Central energy stations and regional energy plants work well for laboratories seeking flexibility and adaptability. Provide utility service distribution from perimeter locations to enable easier laboratory enhancements and equipment relocations.
Most, if not all, forensic laboratories are extensions of city, county, state, or federal governments and require sustainable practice. Aside from their focus to protect and enhance our society, they also have the responsibility of conserving our natural resources. As planners, designers, constructors, directors, and users we must recognize the possibilities available to achieve these important objectives. Whatever your goals are, seek partners with forensic laboratory and sustainable design experience. This is the best way to meet not only today’s needs, but future changes while conserving our natural resources.
Ken Mohr is a Principal and Sr. Forensic Laboratory Planner with HERA, Inc., laboratory consulting partner firm in Crime Lab Design. His 17 years of experience with advanced laboratories includes nearly 4 million square feet of forensic facilities. Ken can be reached at firstname.lastname@example.org
Michael Cooper is a Principal and Senior Mechanical Engineer with Harley Ellis Devereaux, architecture and engineering partner firm in Crime Lab Design. He has 17 years of experience in the design and management of technology based building projects, including a multitude of forensic laboratory facilities. Michael can be reached at email@example.com