Rendering produced before Lam Partners began working on the project, by Shepley Bulfinch
Princeton Firestone Library has undergone a major multi-phase renovation. In the course of space planning, it was determined to re-purpose the atrium separating the older building from the 1980s era addition into the reading room for the library’s rare books collection.
Lam Partners was hired in the fall 2015 to develop a strategy for mitigating light levels from daylight, to assure the library staff that no more than 500lux (46fc) would be present on the desk surfaces at any point in the year.
Glazing across the atrium pre-renovation was 14% VLT (Visible Light Transmission) glass with a 50% opaque brise-soleil mounted below the glass, resulting in an approximate overall 7% VLT (middle image below). The last image is a rendering produced by the architect before the Lam Partners joined the project.
The skylit atrium space, joining the original building with an addition from the 1980s, is over 140′ long, 16′ wide, and will be broken into two zones. The light blue zone in the plan and sections will before regular library reading materials, while the darker blue zone will be reserved for reading and research of items in the Rare Books Library.
Drawings by Shepley Bulfinch.
INITIAL SOLAR ANALYSIS
Illuminance distribution on July 11, at 2pm, a worst case time in mid-summer months due to the off-axis orientation of the space. Clearly the existing glazing cannot accommodate the target of 500lux maximum.
This temporal map below shows yearly illuminance at the circulation desk (center of bay 3), based on typical weather data for nearby Trenton, NJ (the nearest city to Princeton with a TMY3 EPW file).
The images below are dynamic sliders – move the slider to see the light move through the space over the course of the day. The image in the the bottom right is the illuminance at the task plane level.