Understanding the Miami-Dade and Broward County Hurricane Impact Standards

The Miami-Dade High Velocity Hurricane Zone (HVHZ) standards are the most stringent hurricane protection building standards in the United States. All buildings in Miami-Dade, Broward, and the coastal areas of Palm Beach counties must adhere to these standards because of the severity of hurricanes here. Three important ratings that comprise this standard are the missile impact testing, design pressure testing, and cyclic pressure testing.

Missile Impact Testing

The missile impact tests simulate debris hitting the window during a hurricane. In the large missile test, which simulates large debris, such as a tree branch, an air cannon shoots a 9-pound two-by-four piece of wood at 50 feet/second at several spots on the window to see if the window will remain intact.

The small missile test is used to simulate smaller debris, such as gravel, that would hit a window in a tall building. In this test, the air cannon propels 2-gram steel ball bearings at the window at 130 feet/second.

In either the large or small missile testing, the window must remain intact to pass the certification.

Design Pressure (DP)

The DP rating tells you how many pounds per square foot of wind pressure a window can withstand. To test this, engineers install the window in a wall in a specially designed chamber. The chamber creates positive and negative wind pressures on the window to simulate the wind forces in a hurricane. Simultaneously, the window is sprayed with a large volume of water to simulate the driving rain that the window will face in a hurricane. Engineers also measure how much air leakage occurs during the wind and rain testing. The combined results of the wind, water, and air leakage tests form the window’s DP rating. The higher the DP rating, the stronger the window. HVHZ-approved windows are tested and approved to withstand winds of 170+ mph.

Cyclic Pressure Testing

Engineers subject the window to thousands of cycles of positive and negative air pressures in the cyclic pressure testing. This simulates the air pressure fluctuations that occur with a hurricane. The window must remain intact for the entirety of the test. Cyclic pressure testing is different from the DP test because cyclic pressure testing evaluates changing air pressure conditions, while DP testing evaluates static air pressure conditions.

These three tests combined simulate the real-world conditions that hurricane impact windows face:

• How much wind can the window resist?
• Will the window withstand being hit by debris?
• If the window is hit, will it withstand wind pressure for the remainder of the storm?

To meet HVHZ hurricane standards, a window must successfully pass all of these rigorous tests.

CitiQuiet Windows and Doors is one of South Florida’s leading suppliers of hurricane impact windows and doors. Visit our showroom in Boca Raton or call us and we will come to you to help you find the hurricane impact windows that will best meet your needs.

Since 2012, CitiQuiet Windows and Doors has been engineering and installing high-quality impact windows, doors, and shutters for residential and commercial buildings throughout Palm Beach, Broward, and Miami-Dade Counties. 

Based in Boca Raton, CitiQuiet Windows and Doors offers a turnkey service to clients including initial design, engineering, permitting, installation and finish work.  From elegant French doors to hurricane impact-resistant windows and sliding glass doors, CitiQuiet Windows and Doors has your solution. 

At CitiQuiet Windows and Doors, we carry only the highest-quality products from the nation’s top manufacturers – and we stand behind everything we sell.  For a free estimate, contact CitiQuiet Windows and Doors at 561-241-9463, visit us at citiquiethurricanewindows.com,  or stop by the showroom today at 6530 West Rogers Circle, Suite 29, Boca Raton, FL 33487.