Solar Decathlon Design Challenge 2020
Honorable Mention -
Honorable Mention -
Sunblock Elementary is a retrofit school in Tucson, Arizona. The design goal is to fully recognize the potential of the school as a station to produce clean, renewable power, while acting as a hub to uplift the community. Elementary schools in Arizona are funded less than the national average, and all schools would greatly benefit from spending less on energy bills and more on students. The Tucson Unified School District has over 100 schools that share similar building types. The strategies used here could be replicated to positively impact many more communities.
Innovation: Radiative Sky Cooling
During the course of a day, the solar panels generate renewable electrical energy to supplement the electrical demand of the occupied building. Consumptive patterns oppose the production of electricity by solar panels so this grid stress issue was what we chose to tackle innovatively through radiative cooling and thermal storage. This is a new combination of the existing technology in PV panels and technology from the late 1970s that utilizes a roof pond radiative system. A huge benefit of this cooling strategy is that the mechanical system will require little-to-no alteration.
In terms of comfort and environmental quality, the design focused on bringing in natural light, using a light color palette, and incorporating biophilic design.
The main area of the school needing changes following these guidelines were the circulatory spaces, which had no access to natural daylight. The California energy commission noted that exposure to natural daylight was linked to higher levels of concentration and better short-term memory. The Heschong Mahone Group produced a report showing that workers in a well daylit building worked 6-12% faster. We brought in more daylight by installing clerestory windows in the central corridors. We also used a color palette comprised of light colors that would bounce light around the space better.
High Performance Envelope
The project uses continuous air, water, vapor and thermal control layers to take control of the space conditioning energy invested into the school. We used AeroBarrier to improve the envelope air-tightness, reducing leakage of conditioned air to the exterior. Mineral wool insulation helps retain thermal energy inside the building. A membrane material provided the vapor control layer to prevent moisture drive past the thermal control layer as this presents a condensation risk. Waffle membrane finally provided a rain screen air gap and waterproof layer to keep bulk water away from the interior mass timber panels.
The existing corridors in the school did not have access to day lighting. This was addressed by moving the hallway roof up to allow for clerestory windows. Clerestory windows experience less solar gain than skylights and provide an even light quality. This makes the hallways more inviting for students. It also means that there can be less reliance on artificial lighting.