Friday, May 27, 2011

Understanding Your Window Ratings!


U-factor measures how well a product prevents heat from escaping. The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. U-Factor ratings generally fall between 0.20 and 1.20. The lower the U-value, the greater a window's resistance to heat flow and the better its insulating value.

So this window is way good!! =) (.30 US measurement)

Solar Heat Gain Coefficient

Solar Heat Gain Coefficient (SHGC) measures how well a product blocks heat caused by sunlight. The SHGC is the fraction of incident solar radiation admitted through a window (both directly transmitted and absorbed) and subsequently released inward. SHGC is expressed as a number between 0 and 1. The lower a window's solar heat gain coefficient, the less solar heat it transmits in the house.

Visible Transmittance

Visible Transmittance (VT) measures how much light comes through a product. The visible transmittance is an optical property that indicates the amount of visible light transmitted. VT is expressed as a number between 0 and 1. The higher the VT, the more light is transmitted.

So far it would seem this window lets in pretty good light and yet still saves energy. I am really happy about the energy thing! =)

STC Rating

This is the sound proof ratings. It starts at 26 and goes to 54 (being sound proof). 26-28 is the for normal range single pane glass (average of 27) and the range for double pane glass is 26-33 (with an average of 28).

Personally if the average of double pane glass is 28, I'm good with 26 for a single. I wouldn't think it would be that much difference. lol


  1. Thanks for the info....what about screens, do your windows come with screens? Nothing I ever thought about until yesterday and the windows where up and horse flies where buzzing in. I emailed my PM but he is off until Tuesday.

  2. This is very informative...THANKS!

  3. I emailed my PM. When I hear back I can let you know what he told me.

    And thanks!!

  4. Thanks for the info! That's great! Our windows come w/ screens, I made sure to ask because when my parents built a house, they didn't come with the house.

  5. The windows do come with screens. That was one of the questions we had for our PM and he said it is the last thing they install to keep them from being damaged.

    Great post Noey!

  6. Thanks All! I was wondering if it was something they do last or not at all! That is so good to hear!

  7. I'm curious...has anybody tried to latch any of their windows? I noticed that some of our window latches don't line up very well. It feels/looks like they'll break off if you force them. I suspect there's a way to adjust them, so I'll mention it to the PM. Excellent break down of the window stats Noey. Thanks!

  8. steve, i've heard of some people saying the same thing about their windows....also, i found this????....

  9. Some of the info. Was over my head but good to know that they are top of the notch windows. As for screens it did not even cross my mind so good to know that they do have screens. :)

  10. Yes...screens are one of the very last things they install! =)

    My windows are pygrym or something like that. Not patriots.