Trial / Demo
To deliver a world-class museum experience for patrons and staff, IES Virtual Environment (IESVE) was used as a comprehensive performance design and risk-mitigation tool for energy, comfort, UV control, and solar offset.
The Pritzker Military Museum & Library is a non-profit, non-partisan institution located in Kenosha, Wisconsin, that’s dedicated to educating the public on military history, national security, and the role of the citizen soldier. Founded by Colonel Jennifer Pritzker, it features extensive archives, rare books, and artifacts from the Revolutionary War, right up to the present day, focusing on stories of service, sacrifice, and civilian-military connections.
Going beyond building performance
Naturally, a key concern was how the museum was going to operate once it was built, and with a project as complex as this, modeling had to take into consideration a multitude of factors that were specific to exhibits, conservation and artifact protection. That’s why the design team used IESVE to not only look at energy consumption, but also the thermal comfort of the whole space. The huge amount of glass in the design meant there was the potential for artefacts to be damaged by sunlight or temperature variations that could have led to significant compromises or re-designs if these disparities weren’t flagged before construction. And IESVE modeling played a pivotal role in guiding decision-making throughout the project, particularly for these more complex systems. IESVE was also used to study condensate resistance on building elements given the humidity requirements and all steel and glass construction. The scope of modeling enabled:
• Whole-building operation and energy use. What does a 24/7 conditioned building look like from the perception of energy consumption and operating cost?
• Indoor environment and comfort: The accurate forecasting of thermal comfort of occupied spaces, not just pure energy metrics.
• Solar impact on artifacts: Modeling how sunlight enters the very glassy building exterior and its impact on archival materials that could be damaged or destroyed by sunlight.
• Solar glass/panels and frit design: IESVE modelled the performance of different solar glass/solar panel configurations and frit patterns – as well as the need to filter specific UV wavelengths that could degrade artifacts.
• Interaction with on-site solar generation: Discovering how much building energy demand is offset by the solar field.
These modeling insights were designed to help avoid discovering post-occupancy that sunlight on the highly glazed façade was damaging artifacts, as well as ensuring they met strict environmental conditions inside. So, while continuous, 24/7 conditioning could mean increased costs, modeling meant that solar offset was already quantified and factored into operating energy and cost forecasts.
IESVE was used to evaluate daylighting levels and determined that during a majority of the occupied hours for staff and visitors, the natural light levels were above 250 Lux (550 Lux was recommended level) After evaluating the Annual Sunlight Exposure (ASE), it was determined 86.6% of the hours were above the 250 Lux threshold. Glare was also evaluated using Daylight Glare Probability (DGP) and this kept glare in the imperceptible to perceptible range.
Similarly, post-construction validation using real measuring tools including lux and irradiance meters showed the real glass system even outperformed IESVE predictions.
In the acceptance period in commissioning, it was validated that UV-A transmission was less than the design criteria of 2% - and the highest level measured was 1.5%. This subsequent measurement-based validation of the museum’s modelled glass system was a further vindication of IESVE capabilities, that helped refine a system to protect the unique artefacts and ensure the comfort and safety for all its visitors.
Customizing glass and solar specifications based on solid data modeling
A core component of the project was how to predict the outcome of a huge variety of solar panel and glass designs. Many options were considered, and using IESVE meant that each iteration could be modelled accurately to discover its impact. From changing one part of the structure from a glass to a solid roof, or altering the frit patterns on solar glass, or using more traditional solar panels, each element was modelled to ensure the best outcome. The challenge was to try everything, but ultimately, get everything right.
IESVE enabled:
• Multiple solar-generation concepts: Numerous iterations of solar panel layouts and system configurations with physics-based data.
• Testing a glass roof concept where the frit pattern itself was made of amorphous-silicon solar collectors.
• Combinations of this custom solar glass with conventional PV panels.
• Calculating the energy yield of non-standard products including custom amorphous-silicon pattern integrated into glass.
• Compare energy production of these concepts against more typical solar fields.
IESVE allowed rapid iteration of many solar design options, including unconventional PV-in-glass frit concepts, providing the performance data needed to choose between a visionary but costly glass-roof solution and the eventual, more efficient, solid roof and separate solar field. The studied combination of monocrystalline (roof mounted) and amorphous silicon photovoltaics (solar roof glass) amounted to 58.1% annual offset of total energy consumption. Ultimately the project moved to a ground mount array.
How IESVE matched innovation with efficiency
Across this project, IESVE was used to predict and validate building performance including 24/7 energy use and costs, thermal comfort in a highly glazed museum environment, UV control and artifact protection through glass and frit design, and even post-construction verification that the real glass system exceeded modelled performance. Ultimately, by giving the museum solid data, it supported envelope and solar design decisions by exploring every aspect they wanted to integrate and comparing each outcome with their overall goals.
Why IESVE?
“One of the huge benefits of IESVE was the fact that as a single, integrated platform, it not only allowed us to explore a range of options relating to glass design and solar panels, but it also looked at energy, loads, HVAC, daylight, solar, airflow, and compliance – all from the same tool. This was alongside acting as a risk and validation tool that not only compared predictions to onsite measurements, but ultimately, became integral to align our high-performance and conservation goals with a museum everyone could be hugely proud of.”
Benjamin Skelton, President and CEO, Cyclone Energy Group
(All images credit: Tom Rossiter Photography)
