555 Tower | Bellevue, WA Accelerating Building Commissioning with ATS Active Testing (ACT) The 555 Tower, located in downtown Bellevue, WA, stands 600 feet tall and features 21,000 square feet of retail space. ATS provided environmental controls for the shell and core of the facility and was brought back in 2025 to provide tenant improvement buildouts for 21 floors in the building. To provide a quicker, more robust checkout process for tenant improvements, ATS deployed its custom Active Commissioning and Testing (ACT) program to support the close-out phase of the newly completed tenant spaces.
Metric
Result
Floors Tested
21 (20-40)
Equipment Tested
451 Units
Total Duration
<24 Hours
Estimated Labor Savings 150-200 Hours Diagnostic Output
Automated Test Logs and Analytics
Traditional commissioning of large tenant improvement projects can take weeks of manual effort, with teams physically inspecting hundreds of HVAC units to verify performance. By using the ACT program, ATS automated this equipment testing. Instead of taking days or weeks, each floor took less than two hours to complete, and the entire project was completed within 24 hours. “Checking this many devices at this level of detail typically takes a commissioning team of two people about two to three weeks to complete. By implementing ACT, we saved 150 to 250 labor hours while producing additional troubleshooting results that normal commissioning would not have been able to provide.” - Stephen Zellner, Analytics Development Manager, ATS Automation
Smart Testing, Real Insights
Instead of collecting isolated data points, ACT simulated real operational scenarios by changing heating and cooling setpoints and monitoring how each unit responded. Airflow, discharge air temperature, and control sequence accuracy were also measured and logged. The results were sent straight into the ACT program, where a custom ruleset flagged anything out of the ordinary, such as chilled-water valves that didn’t respond, airflow that didn’t adjust properly, or temperature setpoints that weren’t achieved. ATS engineers then used the Alerton building automation system to investigate and correct these issues. The findings were presented to the tenant improvement project team, complete with data-backed recommendations to improve performance and efficiency.
From Findings to Fixes
The data told a clear story. Some equipment showed sluggish or incorrect valve responses. A few air handlers failed to meet airflow targets. There were balancing issues, control sequence errors, and minor calibration