Team Energy Derailment Keeps Things Real with TRACE 700 and Repeats Award Winning Effort!

2016 ASHRAE Building Energy Modeling Conference Design Competition

When it comes to highlighting the importance of whole-building energy simulation, ASHRAE and IBPSA are often at the top of the podium. The second annual LowDown Showdown challenge at the ASHRAE and IBPSA-USA SimBuild 2016 conference in Salt Lake City was no exception.  Building on the success and excitement from last year’s inaugural event, the 2016 challenge was to design a 50,000 ft² net-zero outpatient healthcare facility in Omaha, Nebraska with an emphasis on practical constraints such as cost and limitations on certain renewables. 

Trane TRACE™700 LowDown Showdown Energy Model for 2016 Conference

Fortunately this year’s team Energy Derailment, a combination of Customer Direct Service (C.D.S.) coaches and TRACE customers, embraced the challenge. Building off last year’s award winning teamwork, the team used their diverse background/skills, design expertise, modeling prowess with the power of TRACE 700 to take home the “Most Practical” design award. Given the significant focus this year on more realistic design, we couldn’t be prouder of the team and the end result. Keep reading to see how this team achieved success…

Team TRACE_700_Lowdown_Showdown

About the Competition...

Nine teams were assembled from a pool of more than 80 volunteers to compete in the contest, each using a different core vendor modeling software. The teams were provided a realistic ASHRAE 90.1-2010 compliant baseline outpatient healthcare model that established space usage, area, occupancy, plug loads and other requirements. The teams were then challenged to design and model a proposed building based off of this baseline with the goal of achieving net-zero energy usage. At the conference each team presented their design results to the attendees who were asked to vote on the designs. The results were judged using the following criteria:

  • Practicality: Cost effectiveness, constructability, real-world application
  • Energy: Performance metrics as recorded on the Results spreadsheet
  • Teamwork: Demonstrated collaboration among disciplines (architecture, engineering,  modeling) and overall project management
  • Creativity:Originality of solution, design, use of tools and analysis
  • Workflow: Overall process, problem solving, efficiency and QA/QC methodology
 

The Team

Team Energy Derailment included a passionate group of engineers, energy modelers, and architects with diverse backgrounds and an eclectic skillset. Together with TRACE 700 they formed a powerful team that was laser focused on maximizing energy efficiency within real-world design constraints all while making the challenge a fantastic learning experience. The team members included:

file

Conceptual Approach

As with any building design and more importantly a design with net-zero goals, the early stage integrative approach attributed to the success of the project. The team’s first step was becoming familiar with other examples of net-zero healthcare facility designs to learn from previous work. The team used a research paper from ASHRAE that highlighted a multitude of realistic energy conservation measures (ECMs) that could potentially apply to the project.  Armed with this information the team was able to jump in to the passive design features.

Space Layout:

Without well-defined owner’s requirements, David Bosworth, the team’s architect, took the reins early in the process with a unique approach to determining the programmatic layout. David analyzed each zone individually using adiabatic walls to eliminate exterior influences. The analysis proved enlightening.  It turned out that 14 of the 118 zones consumed more than 50% of the total building energy. 

Leveraging this information and the complex relationships between different space usage types, the team determined that centralizing and stacking these core high energy spaces would help optimize the efficiency of the HVAC system by reducing the distance conditioned central or outdoor air would need to travel to reach the zones.  In addition, the analysis demonstrated that the zones could be clearly divided into three distinct categories; core zones with high energy intensity, secondary zones that were similar to typical office space, and tertiary zones with low energy use intensity. Rhino was used to optimize the design layout by intelligently grouping space usage and programmatic relationships while utilizing the tertiary zones as a buffer for energy intense envelope loads.

file

This provided a complex spatial puzzle that David was then able manipulate to create the final aesthetic aspects of the design. The layout geometry was then imported into TRACE using green building XML (gbXML), an industry standard file format used to share building properties between 3D architectural and engineering analysis software.

file

Integrated Design and Analysis

Passive Design Features:

After the layout was finalized, the team worked to define the optimal building orientation, fenestration layout, shading, and massing to minimize the loads.  Applying a series of initial assumptions, David used a cloud based parametric analysis tool called Apidae to perform a sensitivity analysis to highlight which variables had the largest impact on EUI, HVAC sizing, and simple payback.  This effort allowed the team to spend more time focusing on the most important variables and how to turn the large amount of data produced by the parametric analyses into useful knowledge.

As mentioned earlier, simple payback was an important facet of our design. Cost curves created from a previous contractor survey were used to accurately assess various envelope options.  Once the optimal window-to-wall ratio and massing design were determined, the model was seamlessly updated in TRACE 700 using gbXML.

Lighting and Daylighting:

After finalizing the passive strategies, the team recognized that getting to net-zero energy was going to require a tremendous effort to minimize HVAC and process loads. The next step in the process was to perform an integrated lighting design with detailed daylight analysis.   

The team’s diverse mix of skills once again provided the answer.  Ajit Naik one of the teams skilled energy modelers tackled the design with a holistic approach that minimized artificial light and reduced the probability of glare. To do this he combined some specialized lighting design tools, AGi32 and Diva for Rhino, to determine the optimal lighting layout for each floor with high-efficiency LED lights exceeding IESNA requirements.

Working in parallel, David Holtzclaw focused his effort on analyzing the plug loads and electrical use in the building.  He found three areas where significant load and energy savings were achievable. The baseline model had very inefficient elevators, so David worked with representatives from Kone to find a highly efficient regenerative-drive elevator solution that cut the baseline elevator energy use by nearly 70%. He found that additional savings through high-efficiency office equipment and transformers provided reasonable simple payback.

HVAC Systems:

When it came to designing the HVAC system, the team quickly realized that health care facilities present many unique challenges. This meant dealing with stringent ventilation and air change requirements while maintaining proper humidity, acoustics, maintenance, and other health and well-being provisions. Brian Turner, RJ Hartman, and Spence Shan embraced the opportunity to push beyond their comfort zone and investigate systems they had never designed before. They took a holistic approach to the problem by looking at the building systems in their entirety.  Using this approach it became apparent with the high service hot-water usage that reuse of waste heat was going to be a key factor in achieving a highly efficient solution.

The team brainstormed several different HVAC system designs and settled on a single solution that could meet all of the desired design criteria. A cascading central geothermal system tethered to the service water heating system and combined with high performance VAV provided several advantages.  By centralizing the system the team was able to simplify maintenance with only a single filter location. This system design also provided better zone-level acoustics by eliminating compressors and other equipment in close proximity to the zones.

Finally, the VAV system was easily able to meet the robust air change rates required for many of the specialty space usages. The team then went to work on analyzing various system related energy conservation measures (ECMs) including supply-air-temperature reset, optimal drift points, CO2-based demand control ventilation, and airside energy recovery devices.

file

Renewable Energy:

Renewable energy features were the final aspect of the building to be investigated. The rules of the contest limited the maximum area of photo voltaic cells to 10,000 ft².  David Holtzclaw used the National Renewable Energy Laboratory SAM program to optimize the PV and solar hot water arrays for the proposed building model and location. The final results included 188 kW PV power generation and 865 therms of generated service hot water preheat.

Quality Assurance and Control:

Due to all of the moving parts and pieces of the project, the team needed a process for quality assurance and control.  The team decided to tackle this issue by assigning a single person the responsibilities for collecting, organizing, and vetting the various finalized energy conservation measures in the final models.  With over 17 ECM alternatives, sifting through each alternative to validate the input and results was no small task.  Erik Raith volunteered for this very time consuming role.  He worked closely with Ajit to process the results and help the team meet the extensive documentation requirements of the challenge. 

Final Results

Once the ECMs were fine-tuned and the final proposed model was simulated, the team completed all of ASHRAE 90.1-2010’s compliance forms and submitted a spreadsheet documenting the resulting energy usage and cost between the baseline and proposed design. Below are the final results of the project. The original baseline model’s annual Energy Use Intensity was 145.1 kBtu/ft² and the team’s resulting design EUI is 47.1 kBtu/ft².

file

Although the team was not able to achieve the net-zero goal, the final result was not only three times more efficient than that of the 90.1-2010 baseline, but also a realistic and practical design. The team had a positive experience working together and gained extensive knowledge developing a high-performance healthcare facility of which no one on the team had previously designed. In addition, our team was able explore creative solutions, expand our thought process, and build stronger industry relationships through the process which meant everyone took away something valuable from the event.

A special “Thank You” goes out to the members of team Energy Derailment that selected TRACE 700 as their tool of choice for the contest. The wealth of knowledge and skills each member brought and shared with the team as well the effort put into this challenge above and beyond everyday jobs was inspiring for us as coaches. 

Download TRACE 700 trial software
TRACE 700 software details.

Summary of Team Energy Derailment Energy Model 

Summary of Energy Derailment Energy Model