Over time, mechanical, electrical, plumbing and fire protection systems deteriorate and performance declines. For many old and historic facilities, upgrades to these building systems can be complex and require innovative technologies to remove and replace the existing equipment. KCI used virtual design and construction (VDC) to coordinate the installation of new air handlers at a healthcare facility that was built more than six decades ago.
The facility’s three air handlers were installed during the original construction of the facility in the late 1950s to regulate and circulate air throughout the building. Considerably past their useful life, the units were consuming nearly twice as much energy as a comparable new code compliant system due to an antiquated design and aging control system. Utilizing VDC, engineers evaluated the feasibility of different replacement air handlers and determined the best method of installation.
VDC is a process that leverages digital tools to optimize engineering and construction efforts. Light detection and ranging (LiDAR) scanners and drones document as-built conditions with an accuracy of up to 1/16th of an inch. This data is processed into a 3D building information model (BIM) that serves as a digital representation of the physical and functional characteristics of a site.
The task of collecting and processing field data is expedited while increasing accuracy when recording existing conditions. In less than a day, our team scanned the congested mechanical room and, within the week, created a detailed 3D model of the space. KCI’s engineers then used the digital model to address a host of challenges associated with replacing the outdated system.
When the building was originally constructed, the mechanical room was placed in the middle of the hospital and over the years, the facility has grown around it. With limited space, new units had to fit into the same areas occupied by the existing air handlers. Our team also had to develop a plan to swap out the systems without disrupting normal activities while still meeting necessary air quality requirements. Due to stringent Infection Control Risk Assessment (ICRA) standards, the replacement of the air handlers needed to occur without exploratory demolition. An additional obstacle was the size of the doorway entrance. While modern equipment rooms require a six-foot corridor, the hospital’s older design meant that access was limited by a five-foot entryway. Using the digital model, KCI’s engineers were able to virtually test equipment types and installation strategies to identify a solution that would meet technical specifications and logistic restrictions of the tight space. “We were imagining how this was going to be built even before we got to the hands-on stage,” said mechanical engineer Michael Price, PE. “Virtual design and construction ensured us that our solution was viable.”
A plan to expand the existing doorframe couldn’t completely solve the access challenge, so it was also critical to identify vendors that could customize two new air handlers to replace the existing system of three. In working directly with a fabricator, our design team used the model to break down the units so that each component would fit through the expanded doorframe.
With equipment selected, a phased plan was developed to switch out the systems. In order to maintain service, one unit would remain operational with the use of a temporary fan, while the other two were removed.
Once the new unit was installed, the third air handler could be removed, and the second installation could occur. Mapping out a plan through virtual design and construction created cascading benefits to both the schedule and budget. The virtual model not only saved our team weeks of fieldwork and site visits, but also allowed designers to evaluate alternatives and make decisions in advance of the process. Potential conflicts were identified ahead of time, eliminating associated rework and change orders. Additionally, specific installation details and safety plans were outlined, helping to speed up construction, avoid costly mistakes and safety incidents.
Finding the best solution to execute this project was a balancing act, but with virtual construction, we were able to test out different scenarios prior to real construction, when they were easier and cheaper to solve.
Timothy Reynolds, PE, EMP, CEM, CxA, LEED AP BD+CPractice Leader
With VDC, our team was able to reduce a complex building process and seamlessly coordinate the replacement of the hospital’s outdated air handlers. The end result is an updated system that will meet the needs of patients and staff for years to come.