Retrofitting, renovating, or replacing an existing HVAC system in a multi-story building can be an intricate endeavor, challenging engineers and mechanical contractors with enhancing the system while navigating the building’s current use and original infrastructure. In these projects, additional considerations can include addressing potentially outdated building codes and safety standards alongside accommodating new requirements for system size and capacity.
Fresh Meadow Mechanical Corp., a premier New York-based mechanical contractor, is well-versed in tackling retrofit challenges, having built an extensive portfolio of successful projects over the past 25 years. When the return riser system at a New York City residential building required a complete replacement, building owners entrusted Fresh Meadow with executing the project as quickly as possible to minimize disruptions to tenants and ensure the building’s system was operating at peak performance ahead of New York’s cold weather season.
However, the replacement project was anything but straightforward. The scope entailed completely extracting the original riser that ran from the first-floor ceiling to the 18th-floor mechanical room as well as designing, installing, and commissioning a new dual-temperature system within a highly compressed 21-day schedule. Engineers had to accommodate additional thermal expansion in the new return riser design but faced difficulty meeting new requirements within the riser shaft’s tight dimensions. The final and most critical caveat was that Fresh Meadow needed to employ added measures to minimize disruptions and maintain safety during installation since the building would remain fully occupied throughout the project. To overcome time, noise, and space constraints, Fresh Meadow required a total project partner and turned to Victaulic, a global provider of pipe-joining and flow control solutions, to help meet the project’s demands with engineered solutions.
Space Restrictions in the Riser Shaft
During the design process, Fresh Meadow realized that the system needed an additional expansion loop to accommodate new load and thrust requirements, but the building didn’t have space to spare. Fresh Meadow worked closely with Victaulic’s Piping Movement and Design group to apply an alternative solution that allowed for thermal expansion.
"There was simply no room for an expansion loop within the existing shaft. The owners would need to modify their occupied building, inevitably encroaching on hallway space and evaluating building code, in order to compensate for pipe growth caused by temperature changes using traditional methods like expansion loops," explained Mike Russo, chief operating officer of Fresh Meadow. "Instead, using the Victaulic self-contained [Style 155] expansion joint assembly was advantageous because we could work within the existing shaft."
Fresh Meadow installed two Victaulic Style 155 expansion joints with three Victaulic Style A10 riser anchors at specific levels of the multi-story building to accommodate for thermal expansion and contraction. The engineered solution provided the necessary thermal movement capability without the need for additional coordination, review, and field work that would impact both the schedule and budget.
Minimal Disruptions in an Occupied Building
Construction projects in occupied spaces can be loud and often require cordoning off restricted work areas that interrupt the regular traffic flow in a building. Even with a fast-paced schedule in place to minimize the duration of disruptions, the riser replacement project would still impact occupants for three weeks.
By utilizing Victaulic grooved system solutions, Fresh Meadow controlled the impact on residents, eliminating the need for a hot work safety program and avoiding welding fumes. This approach ensured residents wouldn’t face safety concerns, need to follow diverted traffic patterns on every floor, or experience a noticeable, unpleasant smell from hot work fumes and gases.
“We didn't have to shut anything down or interrupt the tenants at all. We also knew we wanted to cut down on the noise and could do that using Victaulic," said Keith McKee, Fresh Meadow's superintendent for the project. "The only noise was tightening the couplings with an impact gun, which made the building managers happy.”
Optimized Solutions Fast-Track the Project
In addition to minimizing the impact on the residents, the grooved system offered a key advantage during the installation process. Standard pipe lengths on retrofit projects tend to be larger than service elevators, which translates to more time spent cutting pipe spools and, in return, more time spent welding an increased number of joints. The contractor avoided increased material handling time and welding time by using grooved connections, which allowed them to join riser sections within minutes and stay on schedule.
JUST A LITTLE OFF THE TOP: With the needed pipes being taller than the floor-to-ceiling height, they were cut in half for transportation and then grooved connections were used for installation, saving a significant amount of time. (Courtesy of Victaulic)
"The pipes were taller than the floor-to-ceiling height, so we cut them in half to get them upstairs. Adding joints may have slowed us down in a different project, but Victaulic grooved connections made it a more efficient installation. We got the building back online much faster than if we had utilized other methods. It was the adaptability we needed for this retrofit," said McKee.
Going floor to floor, Fresh Meadow cut the riser out of the wall, rigged it down a 17-story shaft, and then removed the obsolete pieces from the lobby level. While the removal phase spanned four days of the 21-day project timeline, leaving only 17 days for the new system installation, Fresh Meadow and Victaulic were confident the team would meet the completion deadline.
Fresh Meadow utilized Victaulic QuickVic™ Installation-Ready™ couplings on the project, which are designed to expedite pipe joining. The two-piece housing design features “shift-limiting slant pads” that allow installers to perform one-touch tightening with high-performance impact guns. The installation process was further streamlined by leveraging Victaulic’s Piping Movement Design team, who provided detailed pipe layout drawings that enabled Fresh Meadow to quickly find and install components as needed. They also coordinated expedited material deliveries so the project could progress from design to installation without pause.
Attention to detail and forward-thinking during the design phase, combined with Victaulic’s Installation-Ready grooved couplings and engineered motion control solutions, contributed to the exceptional success of the project. Ultimately, Fresh Meadow remained ahead of the 21-day schedule, completing the entire scope — extracting the old riser system and installing a new one — in only 15 days.
