When the Building Is Aimed the Wrong Way, Standard Glass Fails - Smart Glass Doesn’t
OUR INSIGHT
We simulated the electrochromic glass using hourly, facade-by-facade tint schedules inside EnergyPlus — rather than static glass properties — so the energy savings could be credibly isolated from the fins and HVAC system already in the design.
The Challenge
A 232,000 sf all-electric office campus in Redmond was designed with nearly every building rotated 45 degrees off True North, the worst possible orientation for managing solar gain and glare. Fixed fins and standard high-performance glazing were already in the design, but the glazing manufacturer needed to know whether their electrochromic product could outperform that baseline in real annual conditions, not just peak-day assumptions. The specific risk was that façade-by-façade solar dynamics on a rotated campus would create glare and thermal load patterns that a single SHGC value and static shading system simply could not address.
Our Role
We worked with the electrochromic glazing manufacturer to develop a detailed energy model of the specific control specifications for their product. Our work gave them a project-specific, code-referenced energy analysis they could submit with confidence, one that held up to the level of scrutiny a campus-scale procurement requires.
The Result
A completed EnergyPlus energy model comparing different scenarios: WSEC 2015 baseline, proposed design with fins, and electrochromic glass design, across the full 233,000 sf building. The electrochromic design reached an EUI of 37.1 kBtu/sf-yr, a 19% total energy reduction and 46% heating and cooling reduction relative to the WSEC baseline, with lighting savings of 48% and an annual energy cost savings of $0.21/sf-yr. The model also quantified the reduction in peak cooling tonnage, giving the design team a defensible case for right-sizing the central plant, a downstream capital decision the energy savings number alone would not have supported.
Services
Electrification | Technology Research | EnergyPlus | New Construction
OWNER: Confidential
CLIENT: Glazing Manufacturer
LOCATION: Redmond, WA
YEAR: 2019
SIZE: 232,000 sf