Reducing construction costs with big fans

RED Studio utilized large-diameter, low-speed fans to move air through the construction company’s 3000-m2 (33,000-sf) office space. The increased air movement allowed for much smaller rooftop HVAC units that require little ductwork.

System costs
Proving the system’s workability and efficiency was just one step in the process of convincing Kiewit to give the ‘go-ahead.’ The more crucial discussion was the upfront cost. Santini’s team basically designed two mechanical strategies—one with the fans, and the other without.

The mechanical engineer obtained the costs of a system without fans with some help from his contacts in the industry. It was then reverse engineered. They went back to the fans and designed a system that eliminated most of the ductwork and reduced the HVAC tonnage.

“With the price of the 17 fans and the price of the mechanical, it actually came in slightly less than a conventional system—about five to seven per cent less,” Santini concluded.

“We told them there would be no cost implication, that it was cost-neutral. Then we reinforced it with the sustainability aspects, from the point of view of air quality, thermal control, and energy efficiency. We didn’t even factor in energy efficiency in the cost breakdown. Sustainability was the icing on the cake,” Santini said.

Kiewit’s Toronto operates believed in the design, and the company recognized the financial and environmental benefits. The project was given the green light.

Long-term, energy efficiency is where most of the savings are. Initially Kiewit’s facility management group took issue with the fans because they were such an uncommon solution. The budget given to the RED Studio team was divided up differently than it would have been in a traditional system. The management group had trouble comprehending a mechanical cost that was dramatically less than what they expected, due to the reduced ductwork and smaller roof units.

“They also weren’t used to seeing a line item for overhead fans, so it became an education,” Santini said.

When the dust settled, both the RED Studio team and Kiewit’s team were happy with the design, and even their mechanical engineer—who at first was a little reluctant—became a big supporter.

As there are 17 fans, there are 17 separate zones of control, which is highly unusual for a building of its size and type. The zones meant each bay of users would have the ability to get more or less air by speeding or slowing the fan.

The fans make a strong esthetic statement in the building—and fit in perfectly with the nature of Kiewit’s business.

Additional challenges
Lighting was one notable challenge for RED Studio’s design. Typically, lights are suspended from the deck, but the presence of the fans precluded that in some spaces. This meant Santini’s team had to go back to the drawing board yet again, and rethink its lighting strategy for the entire building.

Rather than lighting the work surfaces from above, the team designed a lighting system that illuminates the ceiling from below, providing uniform, reflected light off the white surface. High-efficiency outdoor light-emitting diode (LED) fixtures—which normally light urban areas and roads—were brought inside. The fixtures were mounted at a height of 2.7 m (9 ft) within the structural columns themselves, serving the second purpose of a lighting ‘tree,’ and keeping the ceiling clean and organized. The use of high-efficiency outdoor fixtures is grounded in Kiewit’s involvement in road construction and environmental stewardship. The reduced number of units and LED fixtures’ longevity and proximity to the floor all add up to less maintenance. The approach was also cost-neutral compared with alternatives, and resulted in an IES Section Award of Merit for lighting design.

With the lights mounted onto columns, the only thing that is seen hanging from the ceiling are the fans. The fans performed on several levels—mechanically, esthetically, and as an air quality measure.

“As an architect whose primary function and focus is on health and well-being and environmentalism,
I want to make sure that the people are taken care of. So if I can get a mechanical strategy in there that works better than what people are used to doing, I will repeat this formula as often as I can,” Santini said.

Large-diameter, low-speed ceiling fans have gained acceptance for the comfort, energy efficiency, and long-term savings potential they offer. As the Peter Kiewit Infrastructure project shows, with a little ingenuity, they can also represent an upfront savings over more traditional HVAC systems in offices and other public spaces, with the result being a healthier environment for both workers and the planet.

vicky_broadus_BigAssFansVicky Broadus has nearly 15 years of experience as a journalist and is a writer for Big Ass Solutions, which is the parent company of Big Ass Fans and Big Ass Light. She can be reached via e-mail at

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