In 2015 Team IES won Best Energy Use Results in the ASHRAE Lowdown Showdown competition and the winning streak continued after the IES team won Best Workflow at SimBuild 2016 in Salt Lake City. To win this award the team met the brief to design a net zero 50,000 ft2, 3-story Outpatient Health Care facility in Omaha, Nebraska.
Going under the name Insane Energy Savers, the team consisted of the following members: Kent Beason, Joanne Choi, Cory Duggin, Alexandra Gramling, Ken Griffin, Amy Jarvis, Shona O’Dea, Igor Seryapin, Irina Susorova, Tristan Truyens, Brian Tysoe, Scott West and Xiangjin Yang.
The design started by modifying the massing and program to be as climate responsive as possible, while still maintaining the core mission of an outpatient surgery center. Any non-critical spaces were migrated to the second and third floors where a common atrium was added in lieu of the circulation program areas. Exam rooms and office spaces were placed along the perimeter to allow cross ventilation from them through the atrium. Based on wind roses for the shoulder seasons, when natural ventilation is most viable, the building was rotated for the south façade to be in line with the predominant south eastern wind.
Stair stepping the south façade allows the building to self-shade for the entire cooling season and allows for passive heating in the winter as well as passive reheating of air-change dominated spaces on the first floor. Since Omaha has a significant heating season, the R-value of the walls, roof and glazing were optimized to reduce heat loss.
The air change constraints in the first floor program caused the team to consider it separately. A separate dedicated outside air system (DOAS) is used for the critical spaces coupled with earth tubes to precool and preheat the required ventilation air. The non-critical areas use another DOAS with a south facing vertically mounted transpired solar collector for preheating since the windows will be open for cross ventilation during much of the cooling season. All spaces and both DOAS use a geothermal, water-cooled VRV system for their cooling and heating.
The tilted roof of the atrium was designed to hold photovoltaic panels with a 19.6% efficiency. Wind turbines were also used to produce the remainder of the energy required to get net zero.
Click here to see view the Insane Energy Savers’ Lowdown Showdown presentation slides.