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Rack #1, which is 18’2”, has four joints of 44x20 return air duct. The rack is fabricated in Nashville and then sent to a warehouse in Smyrna, Ga., where the electrical conduit/components are installed. This section is the first of 38 racks for the 4th floor West Wing patient rooms. 

The third �鶹��� contractor is Research Air Flo. “We’re handling TAB for the entire hospital complex,” says Kevin Derrick, Research Air Flo CFO. “We’ll be on site in earnest at the beginning of 2023. The D&T includes six energy recovery units, 16 AHUs, 800 VAV terminal units with reheat water coils, and about 5,000 grills. The tower has roughly 4 energy recovery units, 6 air handling units, 1,075 variable air volume terminal units with reheat water coils and 5,400 grilles. We’ll do the bulk of our work in 6 months with four staff present most of the time. As pockets of work become available or milestones approach, our crew will fluctuate up to eight, depending on the need.” 

Both BHW and Knox have ductwork on the mechanical third floor, where they cooperate closely. “We’re connecting to BHW ductwork, so we had to discuss where we start and stop,” said Andy Roy, Knox BIM manager. “BHW also owns the stairwell pressurization through the D&T up to about a foot above the 4th floor, where we connect as well.”  

The contractors contributed design ideas that brought major savings. “BHW gave CHOA almost a million dollars in savings by suggesting they change the grease duct in the two kitchens from double-wall to welded black iron,” Morgan says. “We also rerouted pipes and moved fans to shorten distances.”

Knox designers found that the original energy recovery units used very costly ductwork because they were located on the tower roof. “They would have required piping that got bigger and bigger until the top floor,” Roy said. “We were able to move the energy recovery units onto the 11th floor. This put them in the middle of the building, reducing the size of the ducts. Because they were inside the building, we changed to smaller units, and we also got rid of the expensive ductwork on the roof.”

This is the level three mechanical room.

The project has not been without difficulties. “From a balancing standpoint, the sheer size of having activities over 1.3 million square feet is new,” Derrick says. “The challenge for us will be to close out areas and be able to walk away from them rather than having odds and ends scattered all over.” 

A new challenge and opportunity with this project is prefabricating multi-trade racks prior to installation. “Having all the trades located on a multiservice rack in the tower is a new challenge and opportunity,” Roy says. “It forces the trades to work in one location instead of spread out over the floor, so careful organization goes into making sure the trades communicate when they leave the rack and how they crisscross each other. 

“The rack is prefabbed in the electrical contractor’s warehouse, then shipped to the site, lifted into place and connected. We use about 60-70 racks per floor for the patient tower. We’re coming in in stages. The goal right now is four racks per day will be built, four racks will be shipped out per day, and four racks will be installed per day.”

“Taking care of children who have dire problems at a young age is near and dear to us all,” Derrick says. “In the past 10 years alone, Research Air Flo has completed over 1,300 projects in hospital/clinical environments, including over 200 small projects in the Children’s Healthcare System. We’ve got a long relationship with CHOA and are pleased to be a part of this project as well.”  

“We think it will be great for the kids, for our company, and for our employees, to provide for their families,” Harris says. “This should be a very, very proud project for all of us.

“We always take pride working inside of CHOA hospitals,” Knox adds. “Between our three companies, we’re going to employ over 100 sheet metal workers.”