Low E-Glass Ratings (Building new home in Frisco, TX) (Mansfield: how much, transfer)

[mkh12]

I am builing a new home in Frisco, TX and my builder installed Low E-Glass (Double layer) on all the windows.
I got the following on the Window sticker:

Champion Window
Series 40 SH
Single Hung

Aluminum Frame. Insulated Glass
PP2 Low-E Glass.
A NFRC Logo on the sticker.

Anyone has idea what kind of Low-E Glass is this?
Is it with Argon Gass in between 2 Glass layer?
How many different kinds of Low-E Glass windows available now-a-days from different companies?

Thanks.

[loves2read]

Champion is a local brand--not a national one that some builders use
they send around flyers in the mail about redoing older windows in homes...
think they have plant in Mansfield/Crowley area
Champion Windows, Patio Rooms and Porch Enclosures, Vinyl Siding, Doors (http://www.championwindow.com/StoreLocations/Location.aspx?ID=82 - broken link)

did a google for them
Champion Windows, Patio Rooms and Porch Enclosures, Vinyl Siding, Doors

this is for replacement windows not new construction
aluminum frame/insulated is not as good as fiberglass frame IMO or vinyl--is yours vinyl coated?

doubt that it has argon althought the vinyl replacement windows they advertise do...

[nsumner]

Paging Brian... lh_newbie answer the page please...

[lh_newbie]

(entry music please)

Several items:

1. If it doesn't say argon filled, it isn't.
2. There are a couple types of low-e glass - from what I've seen, several manufacturers are switching to a new type that is less expensive AND performs better. I've heard it called PR2 or Low-E2. Marketing folks. Gotta love 'em.
3. These windows are aluminum frames. Aluminum is a VERY good conductor of heat, which is VERY bad for windows. Aluminum-clad wood, wood or vinyl all have better thermal properties.

Excluding the terms low-e and aluminum - it is most important to look at the ratings of the windows:

SHGC - Solar Heat Gain Coefficient
U-Factor - how well the window resists heat transfer
Transmittance - how much visible light makes it through a window

SHGC - a number from 0 to 1.0, represents a % of how much solar heat is allowed through the window. 0.75 means it allows 75% of the sun's heat into the house (blocks 25%). Windows in the 0.3 to 0.4 range are quite common in our region and would highly be recommended - I've seen lower, but doubt anyone but a custom builder is putting them in.

U-Factor - again, a decimal number, with lower being better. Most folks are more familiar with R-Value for insulation - this is the inverse, so an R-value of 2 is equal to a u-factor of 0.50; an R-Value of 4 is equal to a U-factor of 0.25. Higher R-Values are better, just like lower U-Factor numbers are better. Better insulated windows will slow how much heat is transferred into your home during the summer and slow the heat loss from inside your home in the winter. It's pretty common to see numbers in the 0.3 to 0.4 range also. FYI: This is the overall u-factor for the entire window - not just the glass - it includes the glass AND the frame, so no need to worry about what type of frame you have if you can get these numbers.

Transmittance is just the % of light that makes it through the window, represented as a decimal number. It is very common to see lower transmittance as the window blocks more heat, so a number of 0.50 (meaning only 50% of the visible light makes it into the home) is not uncommon on a good window. Tinted windows will go much lower than this.

[lh_newbie]

For what it's worth, I got some relatively low cost replacement windows for the master bath when it was remodelled. They are vinyl, made by Jeld Wen and are dual-pane, low-e - it is not gas-filled. It still gets a U-Factor of 0.33 and a SHGC rating of 0.35.

Ah... also, if you have windows that are on the North side of your home... aka, no sun... then SHGC is irrelevant and U-Factor is the most important. Fun stuff, isn't it?! Most builders just put the same windows in the home and don't engineer window glazings for the orientation. That's way too much work for a volume builder. It might be worth watching them install the windows, also. Many builders get the windows with tabs and simply nail them up and don't put insulation between the gap of the home's framing and the window frame. Who cares how good a window is if it isn't installed properly and allows air to get around the window design.

Some folks "look down" on vinyl windows because they're less expensive than wood. I personally like them - they don't need painting EVER (in fact, you cannot paint them - it won't stick) - although they really are limited in color selection (Jeld Wen only has 2 colors - white and an off-white). Generally speaking, vinyl windows have the most potential for best insulation if built properly.

Hope all this info is helpful. You're builder is now going to hate me. LOL!

[KantLockeMeIn]

I'd also look into double hung tilt out windows. Where I moved from it was the standard... I didn't even notice the aluminum single hung windows that are typical here until after we moved in. Trying to clean them is a pain.

[lh_newbie]

Single-hung means that just the bottom panel in a window slides (many can be tilted in to clean). Double-hung means both the bottom and top panel can be moved/tilted in for cleaning (or precariously hang out your window - eeks). If you are building a 2-story home and do single-hung windows, you have to use a ladder to clean the outside of the upstairs windows. With a double-hung, you simply tilt it in, clean it and put it back. Single-hung are totally fine on a single-story home.

[loves2read]

you are not going to get those windows changed out at this stage---
just better make sure they are installed correctly with flashing done right and caulked to prevent infiltration...

[lh_newbie]

Yeah, I didn't notice that you said ALREADY installed. Of course, he'll be happy to change them out - at your expense, of course. Change order. At this point, the recommendation to ensure they are properly caulked and insulated will be your primary energy savings method.

FYI: I was curious, since the new Low-E coatings are not much of an upcharge anymore (last time I talked to my window guy - about 6-8 months ago). We are looking at replacing a couple horizontal sliders in some bedrooms, here are the specs, comparing the "old low-e" with the new in a vinyl window:

Low-E.....................U-Factor=0.34 SHGC=0.34 VT=0.58
Low-E 366...............U-Factor=0.34 SHGC=0.23 VT=0.52
Low-E 366 Argon......U-Factor=0.31 SHGC=0.22 VT=0.52

So, as you can see the new low-e coatings block an additional 11% of solar gain - which in our house, the windows we are looking to replace in the next year (one in the kitchen, one in a half bath, one in a full bath and two in bedrooms) would all face East or West, where we have no trees - so this additional 11% of heat blockage would be wonderful. The new low-e does block a little more visual light though (6%), which is hardle noticable. I did include the argon filled for comparison also - as you can see, it primarily affects the U-Factor (insulating value). While it doesn't look like a big change, that is a drop of roughly 10%. 0.34 is equal to R-2.94; 0.31 = R3.22. So that does make a difference - but probably not so much in our climate where SHGC is far more important (we will not be getting argon filled windows, but will definitely get the new Low-E glass).

And finally, for comparison purposes, here are the same specs for the same window in wood:

Low-E .....................U-Factor=0.35 SHGC=0.29 VT=0.53
Low-E 366................U-Factor=0.35 SHGC=0.22 VT=0.49
Low-E 366 Argon....... U-Factor=0.326 SHGC=0.22 VT=0.49

Since a wood frame needs to be a little larger to support the window, VT drops as well as SHGC (less glass). Here are the specs for an alum window:

Low-E..................U-Factor=0.49 SHGC=0.37 VT=0.62

They didn't have specs for Low-E 366 on this window, but you can clearly see that the U-Factor is substantially higher. Due to the strength of aluminum, the frame itself is smaller, meaning there is more glass, which is why the SHGC and VT numbers are higher.

Brian

[pardpatton]

what is the city code requirement for windows in a residence in dallas ?