On average, Americans spend about 90 percent of their time indoors, where the concentrations of some pollutants can be two to five times higher than typical outdoor concentrations, according to an EPA report. So, how is human health affected by an indoor lifestyle?
“If you’re going to be in these [indoor] spaces for long periods of time, what impact, if any, will these spaces have on your health? What can we do to make these spaces healthier and more pleasant in other ways?” These are the types of questions that Jeff Rhoads, director of the Ray W. Herrick Laboratories at Purdue University (West Lafayette, IN), and fellow researchers are evaluating.
As Rhoads explains, the Herrick Labs facility is “eclectic”—housing a variety of basic and applied research centers associated with mechanical engineering and related disciplines. One such example is the Center for High Performance Buildings. “We look at indoor air quality, various technologies that we can put into spaces to make them more livable, how to be more energy efficient, and other things like that,” says Rhoads. “Purdue has a long history of working with equipment companies and building material companies to bring the next thing out to market. These products need innovation and validation based upon basic research. If you put something in a commercial building, you expect to interact with it for decades,” he adds. Teams at the Center for High Performance Buildings partner with industry to create new technologies in sustainable building systems, indoor environments, human perception and comfort, and high-performance equipment. “Almost any type of heating, air conditioning, ventilation, [or] refrigeration system around the world has something in it that has been designed by our laboratories,” says Rhoads, adding that the same is true for noise control systems as well.
Evaluating indoor air quality
The Herrick Labs offer 83,000 square feet of space for students, faculty, and industry. Some of the spaces and features of the building include advanced engine test cells; acoustics, noise, and vibration testing; and an innovative perception-based engineering lab. Herrick Labs has a more than 60-year history of conducting work that has a real-world impact, which for Rhoads, is what drew him to the facility. He has been a Purdue faculty member since 2007, but just recently took on the leadership role as director of Herrick Labs in the fall of 2019. “As a researcher that has spent a lot of time in academia, I have come to learn that it’s not always the case where you can see things happen at a lab bench that then goes on to directly impact society. That’s what you hope, but you don’t always see those success cases. But in my job, I see it on a daily basis.”
Another unique facility under the Herrick Laboratories umbrella is a space known as the Living Labs. Inspired to learn more about indoor contaminants, lighting, and thermal comfort within office settings, researchers created a tightly-controlled set of four open-plan office spaces equipped with many sensors that track the flow of indoor and outdoor air through the ventilation system, amongst other pertinent measures. The goal of one key study? To identify all of the types of indoor air contaminants and recommend ways to control them through how a building is designed and operated. This effort is one of the largest studies of its kind, according to Purdue.
As Rhoads explains, the four Living Labs offices can each be customized or reconfigured. “We can change the ventilation in the room and do tests on how humans perceive that. We can do controls or experiments side-by-side since we have four nearly-identical rooms and we can do different interventions in each one,” he says. “As you can imagine, it’s a unique space to design, and requires a lot of forethought.”
In addition to the sensors, the team deployed a proton transfer reaction time-of-flight mass spectrometer to identify compounds in human breath in real time. They found that isoprene and other volatile compounds linger in the office air even after people have left the room. “Our preliminary results suggest that people are the dominant source of volatile organic compounds in a modern office environment,” explains Brandon Boor, assistant professor of civil engineering, in a Purdue press release on the study. “If an office space is not properly ventilated, these volatile compounds may adversely affect worker health and productivity.” As you may expect, the more people in a room means more emissions of these compounds. Although this study focused on office workspaces, indoor air pollutants and proper ventilation is a concern in any indoor space, particularly laboratories.
“A large fraction of energy consumption in this country is spent on heating, cooling, ventilation of buildings, and small changes in the way we design our windows, furnaces, or air conditioners can have tremendous global impact in terms of environment, human health, etc.,” says Rhoads.
How is lab design evolving?
When it comes to the evolution of laboratory design, Rhoads notes that he has observed the increasing importance of flexible space and the reallocation of space. “In the research world, we’ve gone from having a somewhat clear direction of what comes next, to the need to have space that can be turned over quickly from one big project to the next,” he says. “So, we’re having to spend more time designing in flexible utilities.”
From an efficiency and productivity standpoint, Rhoads has a special focus on the layout of the lab and furniture choices. “How do you place your engineer, students, etc. in proximity to their experimental apparatus? There’s certainly pros and cons associated with that,” he explains. “Debating different things like flexible or fixed office seating—these are things I deal with on a fairly regular basis that I think are huge players when designing new lab spaces.”
As for the future of design and engineering, and the next direction of research at Herrick Labs, Rhoads and his team are certainly thinking outside the box. They are currently involved in a NASA project that aims to develop transformative smart autonomous habitats that can withstand and adapt to unpredictable deep space environments. Rhoads also hopes to expand Herrick Labs’ engagement with agencies like the Department of Defense and Department of Energy, and continue to better understand the interface of buildings and other mechanical systems and people.
“Autonomous buildings and vehicles are certainly hot topics that we’re engaged with at the research level, so thinking about those spaces, how to replicate them, interact with them—those are challenges we enjoy tackling on a daily basis,” says Rhoads.