Thanks to a publicity-shy owner, ENR missed the opportunity to write about the just-complete Sacramento Municipal Utility District's East Campus Operations Center (SMUD EC-OC) net-zero-energy-use project while it was under construction. The project was modeled after the Research Support Facility at the National Renewable Energy Laboratory and included some of the same designers.

This blog offers just a few of the challenges and solutions faced by the design team for the SMUD EC-OC, which was designed to achieve net-zero annual energy use by architect-engineer Stantec in association with the RSF's architect, RNL. Turner Construction was the builder.

The following is straight from Stantec, which also provided mechanical-electrical-plumbing (MEP) engineering services for the RSF. The SMUD project just received the highest rating from the U.S. Green Building Council's green building rating system (LEED Platinum).

According to Stantec:
"The RSF actually served as the learning module for this project and SMUD was designed to be the 'next generation' in commercial design. Many of the same design practitioners from NREL used the “big room” process to make a list of lessons learned and a design wish to develop the approach for SMUD. The primary outcome was that no one major innovation would achieve the results. The following is a list of broad and specific examples of where that comes to life:

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CHALLENGE:  It is possible for any building to be net zero, if enough photovoltaics are deployed. It’s just not economical to purchase the number required on traditional buildings. On this project, there was a significant focus on designing a building that used significantly less energy, to offset the traditional focus on photovoltaics in projects targeting net zero.
SOLUTION: The team utilized the attributes of multiple systems (e.g. radiant slab, thermal storage, dry air source heat pump, among others) which, in the end, did not incur additional cost compared to a traditional construction approach.
CHALLENGE:  In preconstruction design through the use of energy modeling, it was found that due to having radiant heating and cooling in the slab, the building would lose a lot of heat and cooling through this building structure interface.
SOLUTION: A 'drop ceiling' was designed at these locations to separate the radiant tubing from the slab and to incorporate insulation at these locations. The details at these locations were extremely complex but necessary to address this unique situation.
: All building heating and cooling systems needed to meet the multiple requirements of thermal load variations, acoustic requirements, aesthetics and physical constraints.
SOLUTION: An energy audit was facilitated for all consuming items on the entire campus, including large/small electronics, heavy equipment, cooling systems, lighting, and elevators. In addition, we gave careful attention to the complexities of heat flow through and around wall insulation gaps in order to characterize so-called 'thermal bridges' through building walls.
CHALLENGE: Industrial buildings provided the largest challenges. Example: The high ceiling in the warehouse required detailed analysis to assure complete high-to-low conditioning during the winter.
SOLUTION: On the other hand, the massive contents of the warehouse presented an opportunity to reduce cooling needs by means of conditioning during only the cool hours of the day, then letting the massive contents drift in temperature during the warmer hours.