Architectural Design for Health and Sustainability

Editor's Notes

1. Hi, my name is Gwynne Mhuireach I’m here representing the Center for Biology in the Built Environment at the University of Oregon, which Is directed by G.Z. Brown of the Energy Studies in Buildings Laboratory in the Architecture Department, and Jessica Green and Brendan Bohannan of the Institute for Ecology and Evolution.
2. We are a group of architects, engineers and biologists working together to: develop hypothesis-driven, evidence-based understanding of the built environment; transform the design and operation of buildings to promote both environmental sustainability and human health; and to train new generations of innovators and practitioners at the interface of architecture, engineering and biology....like myself!
3. One of the most important reasons to study ecology in the built environment is that we design it. Currently we know little about whether microbial biodiversity indoors is good or bad for us, or if good/bad is even the right way to characterize it. But, if one of our goals is to design healthier buildings, then the answers to these questions are important.
4. We are equally motivated to drastically reduce building energy use, in comparison to current conventional buildings, which in the US are responsible for almost half of all primary energy use (Buildings Energy Data Book, 2010). Admiral Strauss was unfortunately mistaken, because now we are not only concerned about climate change, but also about energy security.
5. Architecture before the widespread use of mechanical cooling systems. This building was considered the first “tall” building – it filled an entire city block Yet it still had a narrow floor plate with operable windows all the way round for natural light and ventilation. Used very little energy
6. In contrast, a more recent building like this relies almost exclusively on mechanical systems for heating, cooling, lighting and ventilation. Some people call this building “the tallest basement in the US” because of its lack of windows. Most of that glazing on the front is spandrel glass rather than actual windows. It is notorious for ventilation problems, and also consumes a lot more energy than we can currently afford.
7. One of our questions is how the changes in building form and the increase in use of mechanical systems have affected the indoor microbial communities, since we already have a good idea about how it’s affected environmental sustainability To begin answering this question, we have been conducting microbial sampling campaigns to discover relationships between passive design strategies and indoor microbial communities.
8. We sampled the airborne microbial communities at a hospital in Portland, Oregon comparing rooms supplied with ventilation air through the mechanical system with rooms supplied through the window. We found that ventilation air source does influence the makeup of the indoor microbial communities. ...
9. ....as shown here in this graph. Along the bottom axis is ventilation energy use, diversity is in blue along the left vertical axis, and proportion of genetic sequences closely related to pathogens is along the right vertical axis in red. The points plotted at 0 ventilation energy use represent the outdoor samples, the points near the center represent the window supplied rooms, and the points with the highest ventilation energy use on the right-hand side are the mechanically supplied rooms. So, you can see that with increasing ventilation energy use, we are finding both less diversity and a higher proportion of sequences closely related to pathogens.
10. Because we had seen the impact of ventilation method in the hospital study, we chose to investigate further in a building that was designed with innovative and low-energy ventilation strategies. Lillis houses the School of Business at the University of Oregon. It is 4 floors, not counting the basement, and one of the several ways in which we sampled the microbiome here was to vacuum dust in almost all of the rooms (in all, 93% of the building was vacuumed!) Architectural design and ventilation are circled here because, while there are many factors which we looked at that may influence indoor microbial communities, these are the two variables that I am discussing today.
11. One of the interesting comparisons that resulted from our dust sampling was between the north and south banks of offices on the 3rd floor. The offices on the north side were naturally ventilated through individual office windows, while those on the south were mechanically ventilated. This plot is an ordination diagram where each point represents one sample, or one community of microorganisms. Points that are closer together represent communities that are more similar, and points farther apart are less similar. NMDS = Non-Metric Dimensional Scaling UniFrac: comparison of microbial communities using phylogenetic information So we’re seeing that N and S offices fall out differently along the vertical axis, which represents a gradient from similarity to outdoor microbiomes like soil and water at the top, to similarity to human microbiomes at the bottom.
12. direct outdoor air vs. filtered and possibly recirculated. We know that filters are changing the incoming microbial community to some degree. direct from window or passing through rooms vs. ducted, and the length of the path. Ventilation air may pick up different microbes from different types of pathways. sized for OSA (based on odor removal, typically around 15 cfm per person), cooling people (300 cfm), cooling spaces (300 cfm for a 150 sf room), or cooling mass (600 cfm). Higher ventilation rates are a primary way to dilute or displace potentially contaminated indoor air. However, increasing ventilation rates will tend to drive up energy costs unless some or all of the loads are handled with natural ventilation. during occupied hours, usually daytime vs. during unoccupied hours, usually night-time (like for night time ventilation of thermal mass, which I’ll describe in a moment). This could be important because the outdoors is the main source of air, and there can be different airborne microbes depending on time of day and climatic conditions. Next I’ll very briefly describe a couple built examples of natural ventilation methods
13. This is the Moss Street Child Care Center at UO, a project that the Energy Studies lab worked on. The building was designed to use natural ventilation to cool all of the classrooms. Air can move freely through the corridor which is adjacent to an interior courtyard, then through the low louvers and windows into the classrooms where it then exits through the outlets high on the exterior wall. The building also uses a thermal mass system, but I’ll talk about the details in the example on the next slide.
14. This is Da Vinci Middle School, another building that the Energy Studies lab worked on. It was designed to achieve net zero energy use and was awarded LEED Platinum certification. The inlets and outlets for this building are sized to bring in enough cool air at night to remove all of the heat that gets absorbed by the thermal mass during the day. Air enters through the operable windows at the exterior walls, moves across the concrete floor and CMU walls, and exhausts through the turbine ventilators at the roof.
15. Designing truly sustainable buildings is extremely challenging. Cooling and ventilation are responsible for a large portion of building energy use, so natural ventilation is an important strategy for achieving sustainable buildings. If it also influences indoor microbial communities in a positive fashion, then it will change the way that buildings are currently designed. We will no longer see the massive floor-plates that fill entire blocks and rely solely upon mechanical ventilation systems. Buildings may once again become more narrow, with operable windows allowing daylight and fresh air to enter every space.