INDUSTRIAL: Lee Mechanical’s 250,000-Pound Sheet Metal Answer to the Data Center Boom

The data center market doesn’t wait. Facilities feeding the infrastructure behind America’s explosive demand for computing power operate on relentless timelines, and when one of Lee Mechanical’s long-standing clients needed a major mechanical expansion at its southeastern Wisconsin facility, the Franklin-based contractor was ready

“This has been a client of ours for quite a while,” says Ken Ahler, President of Lee Mechanical. That established trust mattered on a project of this scale and sensitivity. This was a 200,000-square-foot mechanical infrastructure expansion within an existing one-million-square-foot facility that was completed over roughly 10 months in 2024 for a company that sits upstream in the data center supply chain, providing products and systems that feed directly into the data centers being built across the country. [Per the client’s requirements, the facility and its operator remain unnamed.] 

The Scope

Lee Mechanical was brought in as the design/build contractor working directly for the client, handling mechanical, plumbing, fire protection, controls, startup and commissioning, as well as general conditions management across the expansion. At the center of the project was a new chiller plant built to support 16 custom air handling units that modulate temperatures for 80 server test racks — systems where precise environmental control is a requirement.

The chiller installation alone illustrated the scale of what the team was up against. Getting 52,000-pound chillers into position inside an existing facility isn’t a standard logistics problem. Lee’s team engineered a custom-fabricated equipment dolly specifically designed for the task.

This mechanical infrastructure expansion project involved 52,000-pound chillers. Lee Mechanical custom-fabricated an equipment dolly to use to get each of them into place.

By the time the job was complete, Lee’s team had installed approximately 250,000 pounds of sheet metal and logged 48,000 total work hours over the course of the project. More than 35 skilled tradespeople were on the job at peak, including sheet metal workers, steamfitters, plumbers, HVAC control technicians, sprinkler fitters and service technicians.

“That’s a large project,” Ahler says when asked how 250,000 pounds of sheet metal compares to a typical industrial job in the region.  

Air Over Liquid

What made this particular project distinctive within the data center world was its heavy reliance on air-cooled systems and, correspondingly, the sheer volume of sheet metal involved.

Ahler is candid that the technology landscape is already shifting beneath the industry’s feet. “The data center market is shifting more to liquid-cooled technology,” he says. “At the time this project was done, air-cooled technology was still the predominant approach, but now we’re seeing a shift toward more piping-heavy projects.”

For sheet metal contractors, that evolution is worth watching. Projects like this one where the cooling architecture drives a massive ductwork and air handling scope are becoming less common as liquid cooling gains ground. That makes this particular build something of a high-water mark for air-cooled data center infrastructure work.

Working in Someone Else’s House

The technical scope was matched by a logistical one. The expansion took place inside a fully occupied, actively operating production facility, which meant every phase of the work had to be choreographed around the client’s own employees, schedules and daily operations.

“Navigating major construction like this in an
occupied building poses challenges,” Ahler says. “Whether that’s coordinating shutdowns or managing employee traffic within the building, it required constant communication.”

Lee’s project manager and on-site foreman held weekly planning meetings with the client; projecting two to three weeks ahead to identify which areas of the building required access; arrange for staff to be temporarily relocated; and ensure that egress throughout the facility to restrooms, cafeterias and work areas was never compromised.

But the coordination went beyond schedules. It required a shift in jobsite culture. “We had to communicate to our team to keep in mind that we’re working in someone else’s house right now,” Ahler says. “We wanted to make sure they knew we weren’t just passing through. This meant reminding everyone to clean up after themselves and be professional. We’re guests.” 

A Market Reshaping Southeast Wisconsin

For Lee Mechanical, the data center supply chain sector is a market that has meaningfully changed the company’s trajectory. Ahler says the segment has driven roughly 30% revenue growth over the past two years.

“This particular market has definitely impacted us,” he says. “Something we’ve seen in the past two years — jumps in revenue and in size — impacted by this industry.”

It’s a trend that shows no signs of slowing in Wisconsin. Microsoft began building data center infrastructure in the state three years ago, with projections that construction activity will continue through at least 2033. Multiple additional data center sites are currently under development across the region, and contractors with the workforce, relationships and technical depth to serve that market are well-positioned — provided they can adapt as the technology evolves.