The Draper® FlexShade® ZIP is often used to protect outdoor spaces from sun, heat, wind, and insects. Because the ZIP is used in some especially windy areas, Draper wanted to see how much wind it could withstand. The only question was: how?
Did you know Draper the FlexShade ZIP and its larger cousin, the FlexShade ZIP XL, went through wind tunnel testing? In this “Did You Know?” post let’s talk about why we decided to take this course and what the testing showed.
Wind tunnel testing—what’s the point?
When a shade system is being used outdoors, it’s important that it be as resistant as possible to wind and weather. The FlexShade ZIP is often used to protect outdoor spaces from sun, heat, wind, and insects. Its wind resistance comes from extruded aluminum side channels that incorporate plastic inner channels. Cushioning pads dampen fabric movement, and “zip” details attached to the fabric’s edges keep it in place.
Because the FlexShade ZIP is used in some especially windy areas of the world, Draper wanted to see how much wind the product could withstand.
“We wanted to understand the limits of our product better,” said Clint Childress, LEED®AP, solar control solutions product manager for Draper. “With exterior shading, end users and designers want to know the performance in the elements. The testing helps show and give guidelines.”
How was the testing performed?
For the testing, Draper used Florida International University’s (FIU) Wall of Wind (WOW). Other wind testing facilities couldn’t generate the wind speeds we wanted to observe, plus they recycled their air and were concerned about flying product pieces damaging their equipment. However, the FIU WOW is an open jet wind tunnel, capable of generating wind speeds of 150 mph (241 kph) at 10.5 feet (3.2 m) above the ground. Three sizes of test shades were mounted to a metal support structure custom-built of 3″ x 3″ (7.62 x 7.62 cm) square steel tubing.
Tests were conducted under wind conditions that would be experienced in flat, open ground with few obstructions. Testing started at low speeds and wind was increased at 5 mph increments. Each wind speed was held constant for one minute before being increased to the next level. This process was repeated for each shade until the unit or one of its components flew off, or until maximum wind speed was reached.
What were the results?
Eleven units were tested, including two FlexShade ZIP XL shades. Twice the FlexShade ZIP survived until 145 mph (233.3 kph) and once made it to the maxed-out wind speed of 150 mph (241.4 kph). The screen survived intact with some fabric stretching and was able to be operated to the open position after the test. Only one unit of the eleven tested did not survive well beyond 100 mph (160.9 kph), failing at 95 mph. (152.8 kph). Based on our examination of the data from the tests, we are confident in the FlexShade ZIP’s ability to withstand wind speeds of up to 100 mph (160.9 kph) when in the down position.
To learn more about the Draper FlexShade ZIP click here.
To read our white paper and see complete results of all tests, click here. (This will initiate a PDF download.)