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Volume 23 No. 13
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Kings to try new approach to keeping fans cool and comfortable

The Sacramento Kings’ strategy for developing a green arena was a layup. The city stands out as the capital of California, a state with some of the nation’s most stringent sustainability requirements for construction.

Every year, Sacramento ranks among the country’s top markets for green technology, and the NBA’s newest facility falls in line with the city’s leadership model, according to Kings President Chris Granger.

Giant glass doors at the entrance will play a role in the arena’s ventilation system.
Photo by: Sacramento Kings
“If it matters to Sacramento, it matters to us,” he said. “We went through countless focus groups and surveys as we thought about the building and what matters to people. Very clearly, sustainability was the No. 1 driver of our city and our fans.”

Working closely with arena architect AECOM, Golden 1 Center, named for a statewide credit union, is expected to earn LEED Gold certification after it opens in October 2016. The $477 million arena will be “uniquely Sacramento,” celebrating local culture and the environment, Granger said.

Beyond the typical green elements such as low-flow toilets and solar displays, though, project developers took the next step in sustainability with a displacement ventilation system, tied to heating and cooling the building.

It’s the first of its kind at a major league facility, said Alastair MacGregor, a vice president with AECOM and the

firm’s leader for high performance buildings in North America.

It works like this: the system’s air conditioning unit flows from beneath the seating bowl to deliver a more efficient method of cooling the building’s interior. In most arenas, cool air comes from the top of the building, forcing its way down to the bowl where it collides with warmer air created by the body heat of thousands of fans. Essentially, the two sources of air flow push against each other, wasting energy and resulting in a less efficient system, MacGregor said.

By comparison, the displacement ventilation system, powered by a smaller chiller, provides cooler air at a lower velocity with fewer electrical fans required. The system is designed to provide a better environment for arena patrons, both in thermal comfort and air quality.

For smaller events such as high school and college graduations using half the lower bowl, the system’s design has the flexibility to cool only the space being used, thus extending its efficiency, MacGregor said.

“How many times have you been to a sports event and the venue is really cold when you arrive, and when you leave, it’s on the verge of being uncomfortably warm?” he said. “The reason for that is the HVAC systems pre-cool the buildings to take advantage of that five- to seven-degree swing.”

It’s something the Kings steered away from in arena development by embracing a new model on that piece of design.

Granger said, “We think it’s a really smart way [to condition the building], and a more comfortable way rather than just blowing cold air at people.”

There’s a premium attached to the technology, with additional duct work required over traditional systems, but the Kings expect to recoup those expenses long term through energy efficiency and fan comfort, MacGregor said.

The $477 million arena is taking shape as it moves toward an October 2016 opening.
Photo by: Sacramento Kings
A weather pattern unique to Sacramento and the arena’s grand entrance will integrate with the ventilation system.
At night, a weather phenomenon called the Delta breeze, a sea breeze coming in from the southwest, cools the city by 10 to 15 degrees. The intent is to capture those breezes through smart use of the monster glass doors forming the arena’s primary entrance — measuring 60 feet tall and 150 feet wide — to help reduce the team’s reliance on the overall ventilation system, Granger said.

Separately, the Kings gain LEED points through recycling and reusing 99 percent of debris tied to the demolition of the old downtown mall, site of the new arena. The demolition produced 100,000 tons of material, some reused to help build Golden 1 Center.

Water conservation is a no-brainer in a state going through a severe drought over the past several years. Project officials expect the arena to save 2 million gallons of water annually through various measures, MacGregor said.

One example is the arena plaza outside the building. From a landscaping perspective, planters are placed strategically around the arena to capture and recycle rainwater, “when we do have it,” Granger said.

Moving from Sleep Train Arena near the airport on the outskirts of Sacramento to a downtown arena provides multiple benefits by reducing vehicle miles traveled and related greenhouse gas emissions per attendee by about 50 percent.