Design Pressure (DP) rating on Simonton, BFRich etc.

For all those Replacement Window decisions - just read, review or post a question. You will be helped!
Post Reply
Message
Author
ineedhelp
Posts: 12
Joined: Sun Apr 22, 2007 8:27 am

Design Pressure (DP) rating on Simonton, BFRich etc.

#1 Post by ineedhelp »

I have been researching on the web and the discussion boards various windows and the costs involved. I checked out Simonton 5500 yesterday at a store in Central Jersey and I liked them. The other windows I liked are BFRich (local installer recommendation) and Schuco (very expensive). Here is a question. I noticed that the DP rating of the Simonton 5500 is only DP-25 while the DP rating of the BFRich DP-50. The U-factor, SHGC and other factors are comparable. Did anyone else look at the DP factor? WHy is there is a difference like this?
Any help will be greatly appreciated.

Bill
Posts: 443
Joined: Wed Mar 16, 2005 10:11 am
Location: New Jersey
Contact:

#2 Post by Bill »

Design pressure can be a bit confusing; some of the worst performing windows thermally can have the highest DP ratings.

Design pressure consists both structural rating and water penetration. The standard Simonton 5500 double hung has solid plugs in the corner of the sill that covers the balance channel holes and the primary method water drainage is the sloped sill. The DP rating can be raised to DP-50 by simply changing the solid plugs to slotted plugs that will act like a storm drain allowing water from a strong storm to drain into the main frame and out the weep holes in the front.

I have posted pictures of the solid plug and slotted plug below please click on the images to enlarge.

Image
Image





We are achieving the higher DP rating without adding any sash reinforcement so obviously the window was only lacking in the water penetration side not the structural side of the DP-50 rating. This window sold under the Storm Breaker Label can actually be upgraded to a DP-65 with additional reinforcement.

Here in New Jersey we would only need the higher DP rating if we are coastal where the storms off the ocean pack a punch and are much stronger. Being you are Central Jersey the DP-25 with solid plugs will serve you better. I would not want the slotted plug because you can get a bit of a chimney effect of air coming in the weep holes and up into the sill.

I hope this helps.

Bill

ineedhelp
Posts: 12
Joined: Sun Apr 22, 2007 8:27 am

#3 Post by ineedhelp »

THanks, Bill. That is a nice scientific explanation of the DP rating. I am sure there there are others who are looking for this information.
I think that by looking at the discussion, Simonton 5500 looks like great windows.
Thanks.

Post Reply