Western is currently investing in a "Lab Exhaust Fan Analysis using dispersion modeling to find optimum fan configurations to meet air quality design criteria," says a pamphlet distributed by Cermak, Peterka, and Petersen, professional wind engineering consultants. And for that, we can all breathe easier. Also known as a Wind Tunnel Project the study involves a complex analysis on the exhaust fans in the Chemistry Building, weather patterns outside, and the air quality in neighboring buildings. Why? Well, it works like this:
When students perform experiments in their Chemistry labs, mushroom clouds from their chemical reactions are sucked out of the room via the fume hood. Presto. For me, that was the end of the story. I haven't worked in a chemistry lab since high school and I cared very little then or now about the end fate of odors derived from sulfuric acid. But, as with so many perspectives altered by sustainability research, it turns out that a substance continues to exist after I've no longer any use for it, including a waft of rotten eggs. The challenge is how to dispose of the excess properly, and that's where optimum fan control configurations, air quality design criteria, and energy savings come into the picture.
At Western all the gases generated inside chemistry labs are jettisoned through the roof of the Chemistry Building, lofted by propulsion from four massive exhaust fans. In an urban setting—or a dense development center like a college campus—all those chemical particles are at risk of being drawn back into an adjacent building's fresh air intake. The exhaust fan system exists to push all the fumes high enough into the air that they can disperse and neutralize without adversely affecting the local environment, and carrying fumes to an appropriate height depends on the relationship between exterior weather conditions, the momentum of the exhaust airstream, air temperatures, and so on.
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The present operation of the fume exhaust systems has remained largely unchanged since the buildings were first constructed, providing Western's with a fan system that has two speeds, "On" and "Off." When it's "On" the fan runs at 100 percent, potentially lofting exhaust many tens of feet higher than necessary to avoid the neighboring buildings air intake. When it's "Off," well, nothing happens. Effective, but inefficient. "Wind engineering is best defined as the rational treatment of interactions between wind, the atmospheric boundary layer, man, and his works on the surface of Earth" says Dr. Jack Cermak, co-founder of CPP. With his help, Western is beginning to understand more about the interaction between the boundary layers above south campus, the students below, and how to mitigate their relationship.
Step one will be to map weather patterns around Haskell Plaza and find out how topography, temperature, and surface structures affect airflow patterns, data that can be used for future efficiency projects as well. Step two will be installing technology that can adjust exhaust fan speeds in response to variables in outdoor conditions, meaning, "On" doesn't have to be 100 percent to be effective. "It's super exciting when we can upgrade technology in a building without affecting the current structure and still improve campus and environmental health" said Carol Berry, Western's manager for the 10x12 Program. "The option to retrofit is going to save the university money in installation costs, in addition to savings from lower electricity and natural gas consumption. And we can do this without compromising anyone's physical comfort or personal safety."
Using the new technology, Western can take questions and concerns from building occupants and address them with fine adjustments to automated systems, things that would have been impossible just a few years ago. "We are now at a point in history where a convergence of technologies has the enabling potential to cost-effectively create demand responsive systems at a level not previously achievable" said Western engineer Chris Hadley. "These smart systems will get better. Much, much better. To understand the technology and improve upon it we need to continue investing in systems that provide optimizing strategies. At some point this kind of technology will be entirely self-governing, but that is in the distant future."
As it stands, the Wind Tunnel Project is anticipated to be a significant electrical energy saver, generating fewer greenhouse gas emissions and conserving fossil fuel. The ability to operate the exhaust fan at lower speeds also means less interior air will be vented into the atmosphere, which means Western will have less new air to heat before recirculating it in the building. Reduced demand on the air conditioning is expected to noticeably reduce natural gas consumption—the fuel that converts cold air to warm—a process that may save several thousand dollars annually in utilities, perhaps more.
"The great thing about energy saving projects is they keep saving money" Hadley commented. "We talk about payback for these projects but that is generally only compared to the installation cost. If the equipment and processes remain relatively stable the projects never stop paying back." Just how much money is still a rough estimate but cost analyses, paybacks, and potential long-term savings are extremely positive. "We anticipate saving a huge amount of electricity once the upgraded controls are installed," Hadley said. "Vast!"
As we look toward a future with self-governing systems, or simply smarter ways to combine resources with human ingenuity, the broad goal remains to push Western closer to becoming a climate neutral institution and completing the Climate Action Plan. "It can be hard to incorporate smart technologies into buildings," Hadley concluded, "and this presents something of a voyage of discovery in the process. But it can certainly keep the buildings from working as hard as they do, and that it what we are striving to achieve ." 