Mount Angel ID Roundtable Discussion-Part II

Part II of III - Daylighting (see Part I and III)

The following article, focused on daylighting, continues the roundtable discussion about integrated design, among principal project team members responsible for design of the Annunciation New Center for Theological Studies graduate theology building at Mount Angel Abbey. The participants in this segment of the Roundtable are:

Kent Duffy, FAIA, a Principal of SRG Partnership, Inc. He was the project architect, and also served as Principal in Charge and Project Designer.

G.Z. "Charlie" Brown, FAIA, Professor of Architecture at the University of Oregon and Director of the Energy Studies in Building Laboratory (ESBL). Under his leadership the ESBL designed, built, and monitored the performance of a full-size classroom prototype, in order to facilitate project team investigation and evaluation of daylighting, night ventilation of building mass, integration of mechanical and electrical systems. The prototype also informed and defined the passive systems approach that was incorporated into the project.

Father Michael Mee served as the Chair of the Building Committee. He began working on this project several years before the actual design process started, as the Monastic Community and Building Committee composed their ideas about project aspirations, and maintained his involvement through the construction phase and occupancy.

Kent Duffy: When we think of LEED standards for daylight, we shoot for an average daylight factor of two. The Mount Angel Abbey Academic Center aims higher than that, so that we can still get the minimum amount of light we need into the building during the winter days when there's not very much light available in the morning and in the afternoon. This objective resulted in an "oversized" skylight (compared with typical LEED designs, as well as most daylighting projects) with operable louvers to let the appropriate amount of daylight into the classrooms at any given time. Sensors determine how much daylight is available. Then a control system adjusts the louvers to the proper position to allow just as much light as we want into the space. And I must say that there was sudden applause in my heart when we walked in here before the classroom was finished-with 9,000 foot-candles outside, we closed the louvers, and there were 45 in the room-which was exactly what we hoped for.

One of the big challenges was distributing the light effectively throughout the room. It's not hard to put a skylight in a room, but it is hard to put one in a room without getting a big pocket of glare on one spot and almost no light in another, with a huge contrast between the two. We needed to find an effective way to distribute the light. So these triangular shaped tubes present a flat surface essentially parallel to the sloping plane of the ceiling. They distribute the light to the perimeter of the room. And the tubes are triangular because we wanted to not look up and see the reflector in silhouette against the skylight. So, by getting raking light across the angled faces, we reduce the glare on the silhouette of those elements and distribute the light throughout the room while keeping the ceiling from being dark.

G.Z. Charlie Brown: One of the things that we try to do, in our research role, is provide clear evidence that something will work before we try to use it in the design process. So, when Kent came and looked at the little black box model for our high performance classroom project, we'd already determined that, "Here are some measurements that show, from a daylighting standpoint, that it will probably work." Kent was kind enough and confident enough to say, "Well, I'd like to use that in a building," and we said, "We would love it, but... this is a model, we need to build a full-size prototype in order to assure ourselves and the client that this will work." And in my view, it works. It has a few little flaws that can be refined in future projects.

The skylight louvers allow us to control this skylight. But, in our full-sized classroom prototype, when we put the louvers in, we still ended up with a bright spot in the middle of the room and we got even lower light levels along the edge. The average daylight factor dropped to about four percent, which is about where we wanted it to be, except that distribution was terrible. We made it worse rather than better when we put the shading louvers in.

So, the next thing we did was put in an earlier version of the reflector. And if you'll look at the model, you can see the reflector in it. This is what it originally looked like. All of a sudden, with the reflector, we were able to demonstrate a totally different distribution of light within our model. It's about the same on average-it's a little higher here-but the middle has gone down while the sides have gone up. Now, that's pretty amazing to say I've got a big hole and, all of a sudden I'm not going to get most of the light right under it, I'm going to get more on the edges. We didn't have this in mind. We were trying to solve this problem as we went along. All of a sudden we put this model in the Overcast Sky Box and measured the results and, lo and behold, it did this marvelous thing.

Daylighting Reflector in Classroom

A product manufactured by CPI is used in the skylights. It was designed for solar shading, not for daylighting, so it follows the sun and does all sorts of things. To CPI's credit, they did a lot of work on this product for our application. We did a lot of modifications to the controls to get it to work as well as it does. So, then we said, let's see what happens with the kind of louvers that are in the CPI product. We learned that the average daylight factor was 3.8-very close to the 4.0 we were after, and the distribution was completely even, much more even than what you would get out of an electric lighting system. So, it was at this point we were leaping about the Lab, saying, "Eureka! Eureka!"

Okay, so this chart shows the illumination with a four percent daylight factor and these are months of the year and these are times of the day, these are all the times when it was above 20 foot-candles with a four percent daylight factor. Twenty foot-candles was the minimum target that we had for this space. You can see there is a lot of the time that you can achieve that with a four percent daylight factor. And if you shift that distribution a little bit in time you can do even better. So, this is a use pattern issue. Can they use this building when the light level is adequate? We talked to the Abbey and we looked at it and we said this happens to match really well the use patterns of the school. We spent a lot of time trying to figure out the right amount of light penetration and reflectivity off of the reflector to get it to work right. We built the first reflector in the full size prototype classroom. It was so ugly that we didn't even finish it. But number two was one that we did a better job at. We spent a lot of time building a series of reflector sections for Kent, trying out round, triangular and flat shapes.

Father Michael Mee: The monastic community wanted a building that expresses our Benedictine values of quality and permanence. One example of that is the lighting, which goes beyond just the energy efficiency the lighting provides, to a theological aspect. The students who study here are studying theology-the study of God-and preparing themselves for the priesthood. They sit in these classrooms so filled with wonderful light, but, of course, they're to be enlightened in these classrooms, as well. It's not enough that they're bathed in light, their minds are to be bathed in light, they are to be enlightened. And for us that source of light and enlightenment is the same as God. So, if you will, the building itself is teaching.

Article by Jeff Cole, Konstrukt, Inc for BetterBricks. For details about Mount Angel Abbey, please see an overview brochure on the Annunciation New Center for Theological Studies developed by SRG Partnerships, Inc.

Photos of Mount Angel building are credited to Lara Swimmer Photography. 

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