#Product Trends
Ten Strategies for Sustainable Lab Design
Rethinking laboratory exhaust and ventilation, sharing resources and fume hood sash competitions are all components of designing and operating a successful sustainable lab.
Sustainable design has grown in prominence in recent years as most projects aspire to some level of environmentally conscious design. Research institutions now recognize the significant environmental impacts of their laboratory facilities, and owners are willing to think creatively to reduce resource utilization, improve interior environments and save capital costs. This article provides a set of 10 practical strategies to help guide decision-making to further elevate sustainable laboratory design, regarding resource utilization, carbon footprint and long-term viability. Owners, architects, engineers, and contractors can use these tools to make positive aesthetic and operational improvements without sacrificing the core functionality crucial to research, with the hope of making these strategies commonplace in the near future.
1. Reduced lighting power densities
Lighting averages 10 to 14 percent of overall laboratory energy use. Building codes continually drive down lighting power densities (LPD) thresholds in specific areas, which can be supplemented by localized task lighting for users and/or tasks requiring greater illumination levels. Further reductions are emerging because of increasing affordability of LEDâs for ambient and task lighting, which reduces energy use, particularly cooling loads. Combining density reductions with appropriate levels of natural light and illumination controls can provide even more overall energy savings.
Spatial planning is also a critical component in success of this strategy. Regularly occupied spacesâlabs, offices, conference rooms and break roomsâshould have access to perimeter glazing to take advantage of natural light, while specialty-use and non-regularly occupied areas should avoid the perimeter. Striking the right balance between access to daylight, controls and efficient fixtures can further reduce LPD without sacrificing visual comfort or draining project budgets.
2. Long-term data management
Computational research is increasingly supplementing, and sometimes replacing, traditional wet bench-based science. Digital modeling of experiments enables researchers to rapidly test ideas virtually, replicating only the most promising results physically in the wet laboratory. Facilities are making greater use of onsite data centers to process the massive amount of data generated by these tests; however, this demands a great deal of space, energy for cooling and capital investment in constantly evolving technologies. Cloud computing is the next data management frontier, allowing labs to host minimal onsite data storage while reaping the benefits of limitless capacity, continually updated technology, saved space and reduced utility bills. Several hurdles currently exist for institutions in implementing cloud computing, including HIPAA and other privacy concerns and connectivity reliability.
3. Cogeneration
Large research facilities with high electrical utility costs and concurrent thermal and electrical demand are benefitting from cogeneration (co-gen). Co-gen typically uses natural gas (and sometimes biomass) as combustion fuel to generate electricity, while capturing waste heat in the form of steam and/or hot water. This can be utilized for building heating, hot water, process demands and even cooling. In regions where fuel is cheap and electricity is expensive, and particularly where incentive programs are available, co-gen can be highly cost effective. It can also be one of the greatest opportunities to reduce a facilityâs carbon footprint because grid electricity often results in much higher greenhouse gas emissions. If a laboratory is located where biomass fuel is readily available, this can be a major step toward becoming carbon-neutral.
4. Heat pumps
Heat pumps are available in all shapes and sizes, from major ground-coupled heat recovery chiller plants to small air-source VRF systems, and are likely effective on any project, regardless of size. Typical boilers maximize efficiency at 95 percent, but since heat pumps do not turn fuel into heatâthey simply transfer heat from one place to anotherâthey can achieve 300, 400, 500 percent and higher efficiencies, depending on the system and conditions. Since they run on electricity, heat pumps can be a key zero-net-energy design component when projects also incorporate renewable energy technologies.
5. Resiliency
Resiliency is at the forefront of sustainable facility design because of climate change impacts, such as increased flooding, natural disasters and extreme temperatures. Labs represent a huge capital investment and can exacerbate harm to their surroundings because of the hazardous nature of some experimentation activities. A âresilientâ lab does not look/operate differently from a typical lab; it reflects a philosophy of long-term thinking to ensure the building can maintain operations, structural integrity and safety during the worst possible weather events.
For example, placing vital mechanical, electrical and pumping equipment above predicted flood levels increases long-term viability in the event of prolonged flooding. This opens the opportunity for social spaces at grade, which could publicly promote the research being conducted and/or serve as public/staff amenities. Another resilient opportunity is introducing natural ventilation into certain spaces within the lab. Normally, this feature is an employee perk/energy conservation measure, but during a catastrophic event with prolonged HVAC outages, it could be the means by which the building is ventilated. Resiliency should carry little added cost premium, as it is less reliant on design features and more indicative of good design. In the future, the level of resilience could determine the insurability of structures located in known areas of risk.
6. Renewables
The most common building integrated renewables include wind, solar photovoltaics (PV) and solar thermal. PV has become increasingly efficient and affordable because of reduced equipment prices, government incentives and renewable energy credits (RECs). The major hurdle to implementing solar projects extensively has been their initial cost. Conversely, many solar providers offer owners the benefits of their panels (clean energy at a reduced, fixed price) in exchange for use of their available space onsite through power purchase agreements (PPA). This transferable contract (typically 20 years) ensures energy produced by a providerâs panels will be bought in total by the owner. All first cost and ongoing maintenance is covered by the provider, whose profitability relies on energy delivery. Eliminating this hurdle means the owner can invest in a slight structural premium to manage the added load and pay off this premium through ongoing energy savings via the fixed energy rate.
7. Building dashboards/user interface
There are many approaches to building metering, but it is crucial to use this information to enhance building performance. Some strategies rely on remote monitoring and algorithms to automatically detect issues and suggest corrective action to facilities staff. Other systems rely on providing immediate graphic feedback to users and educating and engaging them in energy-reduction efforts. These graphic displays can be used in the lab to help change user behaviors. One example is cubic feet per minute (CFM) counters displaying real-time lab exhaust rates. When fume hood sashes are open, the CFM display goes up. Institutions are using this data to hold friendly competitions with incentives for the lab users, encouraging them to close the sash when the fume hoods are not in use. Fun, low-cost programs that engage users in meaningful ways pay huge dividends over the life of a building.
8. Collaboration/resource sharing
Collaboration is an industry buzzword that typically focuses on sharing ideas with other research teams within an organization to increase the rate of discovery. Expanding collaboration into resource sharing is a way for institutions to reduce the quantity and cost of lab equipment. Many labs reserve fume hoods similarly to how office personnel reserve conference rooms. When resources are shared, less space is neededâequating to lower operational and maintenance cost. Another hidden savings from higher collaboration is evident when considering time. When successful endeavors are completed in less time and with greater efficiency, the entire institution benefits from greater speed-to-production.
9. Building envelope design and commissioning (BECx)
As buildings become more efficient and as exhaust rates are continually reduced, the building envelope becomes a larger driver of laboratory energy consumption. The three largest âholesâ in typical laboratories include: glazing, infiltration and thermal bridging. The optimal amount of glazing in labs is <30 percent of the wall area. Exceeding 40 percent significantly increases first-cost (HVAC system capacity) and long-term energy cost. To address this issue, infiltration standards have been developed to define building envelope air-tightness testing, such as ASTM E1827 Standard Test Methods for Determining Air-tightness of Buildings Using an Orifice Blower Door. Knowing there will be an air-tightness test often results in contractors achieving very tight envelopes that outperform the specified maximum infiltration rates.
Contemporary energy codes specify âcontinuous insulationâ to address thermal bridging, meaning only fasteners (nails and screws) can penetrate the continuous insulation (not structural elements, such as brick-ties and z-girts). Most buildings do not meet code minimum insulation levels because of this common misunderstanding. Several products are available to minimize thermal bridging, such as fiberglass channels, thermally broken brick ties, structural plastic spacers for steel connections and knife-plates to support relieving angles. By specifying these products and contracting proper QA/QC, the gap between predicted and actual energy use will continually narrow.
10. Laboratory exhaust and ventilation
The latest trend in zero-net-energy laboratory design involves synergizing strategies that dramatically reduce exhaust rates and support a healthier indoor environment: filtered fume hoods + enthalpy wheel heat recovery + air quality monitoring + reduced minimum air-change rates + hydronic supplemental cooling.
Filteed fume hoods capture contaminants within a bank of integrated, top-mounted filters and release the filtered air directly back into the room. While these may not be applicable for all laboratories, they capture a wide range of chemicals, are becoming more common and significantly reduce exhaust demand. An added advantage is the remaining exhaust is general room exhaust (not dedicated fume hood exhaust), meaning enthalpy wheels can be used for heat recovery without significant concern about cross-contaminating ventilation air. Since lab air is continually filtered of impurities and chemicals are not being exhausted into the ambient environment, the indoor environmental quality is vastly improved.
Once exhaust rates are not driven by fume hoods, the minimum air change rate (ACR) setpoint can be reduced. Air quality monitoring adds an additional layer of safety by detecting fugitive emissions, which activates an alarm and increases exhaust to a higher purge rate. This combination of strategies reduces the typical 6 ACH easily to 4 ACH, possibly lower. During unoccupied periods, 2 ACH (possibly lower) is acceptable.
Since it is unlikely for multiple labs to experience simultaneous spills, the HVAC system can be designed to purge as few as two zones at once, saving significant first cost. After this, cooling loads become the primary airflow driver. The remaining demand can be overcome through supplemental hydronic cooling via fan coil units or fan coil units serving chilled beams. This results in nearly complete decoupling of ventilation and space-conditioning systems. Overall, this combination of strategies can reduce laboratory energy consumption at least 50 percent.
