The resulting design encourages air flow throughout the stadium, while keeping the playing surface dry enough to continue tournament play. Since the venue is never completely sealed shut, the presence of outdoor conditions is still felt by everyone inside, and the temperature inside will usually be within a few degrees of what it is outside.
“Think of the roof as having an effect similar to standing underneath an umbrella during a rain shower,” Payne said. “It protects the spectators from the rain, but you are still aware that it is raining.”
The design process began with analytical models that demonstrated how the wind in the area around the stadium typically behaves — such as seasonal wind directions and wind speeds — and how the air would ultimately flow through different configurations of the stadium. It was also critical that the air had a pathway to flow through the stadium without influencing conditions on the tennis court.
The stadium seating consists of a lower bowl, with an open concourse on its upper level to allow breeze to pass through from all directions. Additionally, the upper seating is built only on the east and west edges, with the north and south faces featuring an impressive terra cotta-louvered façade. This façade has been carefully designed to allow cross ventilation of the stadium, but keep out most rain and direct sun.
In addition, an underground air pathway was developed that will passively cool the courtside seating without impacting gameplay.
“Since the ground temperature is typically a few degrees cooler than the ambient temperature, it is used as a passive cooling system as the air flows through the chamber, keeping the temperatures at court level more comfortable,” Payne said.
The system requires wind speeds of at least 5-7 miles per hour to maintain the desired temperature levels. If wind speeds fall below that threshold when the roof is closed, fans will operate to provide the required air movement within the stadium.
“Although the fans will be operational at the USTA’s discretion, they will not be needed most of the time for the system to work as intended,” Payne said.
Payne said that WSP also demonstrated how the retractable roof and the ventilation system could be used to improve game-time climate conditions even when games aren’t being played, such as closing the roof between sunrise and when play starts to protect the thermal mass of the stadium from the direct sun.