Building Analytics for Critical Environments
Fifteen years ago, a hospital in Macomb Michigan added a new surgery center wing to their expansive campus and needed building analytics. On the surface, the new addition began as a way to provide quality care with expert surgeries, but deep within the bowels of the hospital, the essential mechanical and control assets serving the new surgery center were suffering from performance issues and band-aid approaches from the very first day of occupancy.
Patient safety and comfort is essential to any high-performing healthcare facility. Since the very opening of the new addition, the surgery center had continual problems with the operating rooms (OR) maintaining proper pressure relationships, which in turn lead to constant issues with temperature and humidity requirements. The ORs were not able to maintain the proper positive pressure relationships required at the design airflow of 25 Air Changes per Hour (ACH), so the Facility Team was forced to increase in the ACH rate in all OR spaces in order to achieve the required positive pressure relationships.
Facility Managers shouldn’t have to run their systems to failure.
This increased Air Changes per Hour (ACH) had a significant cascading impact on the entire system. In order to properly condition the increased airflow required for the modified ACH, the air handling unit (AHU) serving the ORs had to work excessively hard, which included a tremendous increase in its need for more cooling capacity. This demand for more cooling capacity forced the two air-cooled chillers serving the addition to operate well beyond their design capacity, so they were never able to function properly.
For fifteen years they believed the two chillers were the issue within the system as they could never properly meet the cooling requirements of the modified system, so they continued down the path of running the chillers to failure, blowing compressors, replacing equipment, and never being able to truly solve their issues. Eventually, the chillers failed beyond repair and two rental chillers were brought in to keep the system operational. It wasn’t until the addition of building analytics that they were able to discover the root cause of their system troubles and finally put an end to all their headaches.
The demand for more cooling capacity forced the two air-cooled chillers serving the addition to operate well beyond their design capacity, so they were never able to function correctly.
THE PLAN
Three years prior, the Corporate Director of Facilities spearheaded a plan to implement building analytics & fault detection across his entire portfolio of hospitals, 11 sites in total, which proved to be an extremely forward-thinking and beneficial decision for solving the issues at the surgery center. When the root cause continued to go unsolved and the hospital was entering its third year of having two rental chillers on-site, the leadership of the hospital demanded a resolution immediately. In response, the Corporate Director of Facilities decided to leverage the building analytics (fault detection) for the surgical center and have a trusted Engineer do a deep dive into the data to determine a path forward. His Engineer started to analyze the data and worked on-site with the facilities team in order to fully understand the nuances within the facility: the pain points, the trials, the continuous equipment replacement, and the high cost of failure that the facility endured for many years.
The Engineer began by reviewing the original design documents and the most recent test and balance reports to evaluate system functionality compared to current Michigan State guidelines. The Facility Guidelines Institute (FGI) and ASHRAE Standard 170 are the authoritative sources that the State of Michigan adheres to, and those standards state that the minimum required rate should be 20 ACH (Air Change per Hour), while the maximum air change rate (per hospital standards) should be 25 ACH.
The first obvious problem was that due to the continuous increase in OR airflow over the years in order to maintain positive pressure, all spaces were operating at an air change rate in excess of 35 ACH, with some ORs above 40 ACH. This excessive airflow not only causes pressure relationship nightmares, but it makes maintaining temperature and humidity set-points near impossible. This was the first clue to the Engineer of uncovering the root problem. The chillers were not the problem; it was how they were being operated, they were just trying to respond to system conditions that they simply weren’t designed for. The need for the facility team to excessively increase airflow was due to the poor design of the operating room doors which were never able to seal properly and therefore lead to the constant problems controlling the pressure relationships.
It wasn’t until the addition of building analytics that they were able to discover the root cause of their system troubles and finally put an end to all their headaches.
