I'm looking into replacing some old drafty windows in my house, and when I went to the showroom yesterday, every window had these NFRC stickers plastered on them. Honestly, it felt like trying to read hieroglyphics. U-factor, solar heat gain something-or-other, visible transmittance...um, what? I mean, I get that they're supposed to help me pick energy-efficient windows, but I'm a bit lost here.
Does anyone have a simple way of breaking down what these numbers actually mean? Like, is there one rating that's more important than the others if you're in a colder climate (Midwest winters are no joke)? Or maybe some tips on how to use these labels to compare different windows side-by-side without getting a headache? Would appreciate any insight or even just your own experiences dealing with these labels.
"Like, is there one rating that's more important than the others if you're in a colder climate (Midwest winters are no joke)?"
I totally get your confusion—I went through this last year when we replaced ours. For colder climates, the U-factor is probably your best friend. Basically, lower numbers mean better insulation and less heat loss. I just lined up the windows side-by-side and picked the lowest U-factor within my budget. Honestly, once you narrow it down that way, the rest of the sticker stuff matters less...at least it did for me.
Yeah, the U-factor definitely seems key for colder areas. When I was researching this stuff (first-time homeowner here, so lots of Googling...), I also came across something called air leakage ratings. Apparently, that's about how much air sneaks through the window frame itself—lower is better, obviously. Seems like pairing a low U-factor with low air leakage would be ideal for harsh Midwest winters. Anyone else look into that?