As an addendum to that video, here's an explication of what the ratings mean -
U-Factor - Measures how well a window keeps heat inside. The lower the U-Factor, the better a window resist heat transfer.
Energy Rating (ER) - The ER is the bottom line for energy-conscious consumers as it is the indicator of the window's thermal performance during the heating season. The ER is not a temperature rating. It is a scale rating the comparative performance of windows based on three factors: 1) solar heat gains; 2) heat loss through frames, spacers and glass; 3) air leakage heat losses, regardles ofhow or with what materials it was built. The ER can be used as an idicator of the effect the windows will have on your heating bill.
R-value: A measure of the resistance to radiant heat (temperature) loss. A higher R-value glass has a greater resistance to radiant heat loss.
Also, it's important to note I've read that a triple pane window can actually be excessive (money wasted). It all depends on the exposure the window gets. Example - my house gets full sun at the front, back and left side, but the right side of the house doesn't get any. My understanding is there would be little to no benefit if I installed triple pane glass as opposed to double pane glass on the right side of my house. Many people install triple pane windows in their entire house but don't know that it's actually of no benefit. Installers don't say this for obvious reasons.
I'll try to find you some info regarding this as it was a while ago I read all this. Memory recall can be incorrect or missing links
. I don't want to give you erroneous information.
