Mixed-Use High-Rise Retrofit, BOSTON, MA
For this mixed-use high-rise building, we accomplished a turnkey complex riser retrofit despite challenges such as manpower limitations due to COVID-19 restrictions, and a tight schedule.
Even though the elevator machine room was beneath the condenser water risers, and all work had to be completed during a few winter months, we engineered solutions to help minimize disruption and completed the project ahead of schedule.
We also created an animation of our project solution to demonstrate feasibility in a timeframe where cooling was not needed.
This confidential real estate customer wanted to achieve greater property marketability through riser modernization in a 32-story building. The upgrades had to be completed in a tight, weather-dependent timeframe.
The primary challenge of this project was that 14 stories of 18-inch, schedule 80, piping risers had to be replaced within three winter months when cooling wasn’t needed. The only two possible alternatives (provide temporary cooling or run a new set of risers and schedule a cut over the following winter) would have greatly increased project costs.
The secondary challenge was the project took place during the coronavirus pandemic. Increasing manpower wasn’t an option given COVID-19 restrictions and tight quarters in the pipe shaft.
Our solution was to design and install a steel structure connecting to the cooling tower support steel that carried a five-ton trolley and a five-ton, 460-volt electric chain hoist. We custom-fabricated the chain hoist so that it could be mounted just below the roof, and both the chain and the controller would reach to the base of the riser at the 18th floor mechanical room, 160 feet below.
We cut the condenser water pipe into seven-foot lengths, rigged them into the shaft opening, connected them to the electric chain hoist, and welded them in place. We also installed a ventilation system at the top of the shaft to help prevent odor migration into tenant spaces.
We brought in a structural engineer to design the rigging steel, pipe hangers, and platforms where welding was performed.
It was mid-December before the weather was consistently cold enough to take the cooling towers off-line. We demolished the existing risers and installed the new risers, finishing the project two weeks ahead of schedule.
This prominent building is a LEED Gold certified, 730,000-square-foot, 32-story, office tower located in a downtown financial district. This client chose us because of our extensive experience performing complex air conditioning system retrofits on a turnkey basis.