Labs are energy guzzlers, but efficient energy monitoring can help reduce energy usage.
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Laboratories are notorious for their extraordinary energy consumption, often using six to 10 times the amount of energy of a normal office facility. As more and more attention is given to reduce lab energy use, it becomes increasingly more important to understand the energy drivers in labs to better target energy-conservation measures and improve occupant behaviors. Lab energy monitoring gives facility personnel the insight they need to identify lab energy use, implement effective energy reduction strategies and monitor ongoing energy consumption to ensure lower-energy labs stay that way.
Lab energy consumption can be broken down into a relatively small number of categories: lighting, plug load and heating, ventilation and air conditioning (HVAC). Lowering the energy consumption within each of those categories involves decision making around one or more strategies: improving the efficiency of the equipment itself, improving the effectiveness of the related controls for those devices or focusing on improving the behavior of lab occupants. But which combination of focus areas and strategies will yield the best return? Energy monitoring can help sort out the possibilities.
Energy monitoring and airside efficiency
HVAC energy consumption is by far the largest subcategory of building energy use, so identifying ways to optimize the airflows in a lab will often have the largest impact on a lab energy-reduction initiative. One complicating factor, however, is that airflow in a lab is used for different purposes. In addition to regulating the temperature by providing the proper amount of heating or cooling, additional supply air might be needed to meet the needs of fume hoods in a lab, and even more air might be needed to achieve a minimum dilution of air for lab occupants, particularly when there are benchtop procedures being performed.
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Figure 1 shows an “energy driver” mapping of several different labs, making it easy to see what percentage of time each lab is driven by thermal, fume hood or dilution requirements—as well as the amount of time the lab is running at design minimum flows.
Lab areas driven by their thermal load may be good candidates for lighting, plug load and occupant behavior programs to reduce any unnecessary equipment use driving this requirement. Similarly, labs driven by their fume hood usage can be further reviewed to determine if sashes are properly managed (an occupant behavior program), or to consider implementation of a more efficient fume hood strategy (an equipment/controls-focused program). Once again, energy monitoring can provide information to guide that determination.
The use of visual data helps sort a tremendous amount of information into something that can be easily understood. Knowing the sash is open right now doesn’t help identify whether the sash is managed properly, since a lab researcher could be conducting a procedure in that fume hood. However, knowing what the sash position has been over a week or more helps determine if that sash is opened only when needed. Looking at Figure 2, it’s easy to see some sashes have been in a full or partially opened position for an entire week—probably longer than most researchers spend standing in front of their fume hood.
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Using information to align energy and safety objectives
When airside efficiency discussions begin to focus on determining the “most appropriate” air change rate for lab dilution purposes, a battle is often in the making between facility managers and lab safety personnel. The most common (mis)perception is achieving progress in one goal—for example, lowering lab energy use— requires the sacrifice of another goal—for example, maintaining safe lab environments. How can this seemingly irreconcilable argument be resolved? Get more data. Lab energy monitoring systems can also be used to provide data that helps drive informed decision making around lab air change rates.
Labs can be instrumented to detect airborne contaminants in lab spaces, and this data can be used to improve the controls of the lab ventilation system and provide 24/7 information about lab air quality to environmental health and safety (EH&S) personnel. Utilizing this data, facility managers now can team up with EH&S departments to both lower energy consumption and improve the confidence about the safety of lab environments. Figure 3 illustrates how detection of airborne contaminants can be used to implement a demand-based ventilation strategy that optimizes airflow based on actual lab conditions.
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Maintaining energy savings entitlement
So now a lab has implemented a few energy strategies. The lab improved its lighting occupancy controls; replaced some really old freezers with a single high-efficiency unit; and perhaps implemented some demand-based ventilation controls—the lab even held a “shut your sash” campaign. So how do lab owners know that effort has paid off? More importantly, will these measures continue to work over time? Now that the celebration pizza party has been held for the winning department, will everyone still be as diligent about managing their fume hood sashes? Just ask the energy monitoring system.
A simple check of a labs’ energy consumption “speedometer” (Figure 4) can tell if it’s still achieving the same level of energy savings as when these measures were first implemented.
In many ways, a good lab energy monitoring tool is like a good GPS application. Lab energy monitoring systems help lab users understand where they are by showing them current energy use and energy use over time so they can identify true energy drivers within their labs. This helps plot a path to a lower energy destination, and users can continue to use monitoring to measure their progress and improve their program execution. And, as most know, an effective energy management plan is more of a journey than a destination, so energy monitoring tools will play an important ongoing role for the entire lifecycle of that lab facility.