Best Value Window And Door Company

2128 E. Holt Ave. Milwaukee, WI 53207                               414-483-1716

Who Makes The Best Window?


Answer : That would depend on what you mean by "BEST". I once saw a Canadian window at a trade show, the Arctic Shield (?) that was a triple pane low e with  krypton gas fill. The Vinyl frame was 10 inches wide with a wood core. It had an incredibly low U factor something like a .12 or .11. I was told this works great in northern Canada or Alaska where winter temperatures often exceed - 40 F. The trade off that you have though is a very wide framed window with a comparatively small glass area and glass that is so dark it looks heavily tinted. I suppose someone could make the claim that this is the best window since this is the most energy efficient window.


If you live in the desert south west you might consider windows with double (or more) layered low e glass on both panes. You would not notice the darker tint to the windows since the sun shines very intensely most days of the year. The purpose of this glass is to strongly block out long wave radiation heat from the sun. Unfortunately, the more the more long waves from the sun that you block out, the more visible light you will also block out, hence the darker glass. The extra low e does not lower the U factor significantly if at all. So that means it has little or no effect on the conductive heat inside your house exiting through the glass during winter. In technical terms, the lower the solar heat gain coefficient, (SHGC) the lower the visible light transmittance rating.(VT)     


 For Wisconsin where most days are overcast, you do not want a window with a VT rating of less than .50. This would give that type of low e an almost unnoticeable slight tint and would be excellent (but not the best) at blocking inside heat loss. Keep in mind that for a window to meet energy star standards in the north region it's SHGC rating can be anything. That means the long radiation of the sun is not intense enough to be taken into consideration.  The low e glass that is best for Wisconsin will block out the reflective radiant heat that is the main problem in the northern hemisphere. This is the heat that reflects off of surfaces and comes in through the glass. This low e glass also has an added benefit of having what's known as a Winter Solar Heat Gain Coefficient. When the sun is low in the sky during winter, this low e will allow the sun's long wave radiation to come in ( but still block out the harmful UV rays) and will add heat to the inside of your home. The heavier low e glass and triple pane do not have this quality. The little added energy efficiency of the  window with triple pane low e and Krypton gas is at least somewhat offset by the U Factor .30 window's winter solar heat gain.


So, the answer to the question  "Who has the best window?" would depend on what part of the world you live at.

For Wisconsin  U Factor .30 or less, a  SHGC (solar heat gain co - efficient) rating of .30 to .27,  a VT (visible light transmission) rating no less than .50, (unless you don't mind dark glass)  a non metal spacer system like super spacer or duralite. Metal spacers between the glass cause expansion and contraction during Wisconsin's seasonal changes which will eventually result in seal failure. Very important - make sure the window has a lifetime warranty on all parts, including glass breakage.