Impact window ratings can be a little confusing. At ASP Windows and Doors, we’re experts in supplying and installing the best hurricane impact windows. We provide you with an overview, so you can make an informed decision when buying impact windows.
Let’s begin with the basics. Two terms you might come across when doing your research are Design Pressure (DP) and Performance Grade (PG). This entry will describe these terms and their relevance to your safety during hurricane situations.
Some Background on DP Ratings
Design Pressure rating is an older value representing the capability to withstand wind pressure. This rating, symbolized by a number, encompassed three different criteria: water infiltration, air infiltration, and structural load. The higher the number on the scale, the better the resistance to the benchmarks.
Let’s consider a window or door service in Houston with a DP rating of around 50. It should pass a test pressure of 75 pounds per square foot or about 200 miles per hour. However, some manufacturers misrepresented that rating when providing hardware. DP ratings only have to meet two out of three components on such a test. Most fabricators only disclose the lower segment, but some misleading manufacturers utilized the higher number to misrepresent the effectiveness of their product.
The PG Rating
Therefore, the Performance Grade rating came into existence to encourage more accurate measurements of efficiency. A product with a PG rating must meet all three of the criteria above, including water infiltration, air infiltration, and structural load. A hurricane door with a PG rating of 40 may possess two aspects that rate in the 50 range, but the door receives the lowest score.
The Simplest Way to Read Ratings
Let’s simplify the numbers. The Saffir-Simpson Hurricane Wind Scale classifies hurricanes in the following format:
- Category 1: 74-95 mph
- Category 2: 96-110 mph
- Category 3: 111-129 mph
- Category 4: 130-156 mph
- Category 5: 157+ mph
Imagine every 10 points in the DP rating as the equivalent of a hurricane level. A DP rating of 30 should be able to survive a Category 3 hurricane, a DP rating of 40 should withstand a Category 4 hurricane, and so on.
Keep in mind that these ratings apply to sustained winds. They do not consider wind gusts, projectiles, or tornadoes that often accompany hurricanes. Another thing to remember is that although the Category 5 hurricane starts at 157 mph, we are recently enduring storms with sustained winds of over 200 miles per hour, which might necessitate a new distinction as a Category 6 hurricane or even higher on the scale.
Allow ASP Windows and Doors to Evaluate Your Home’s Safety
Are you unsure of the DP or PG ratings of your windows and doors? Call ASP Windows and Doors at 786-870-4735 and allow our team of certified technicians and specialists to evaluate the safety of your home. Don’t entrust the safety of yourself and your family to subpar windows and doors. Be positive that your home is ready for anything a hurricane might throw at you.