Window Manufacturing Quality Between Companies

Hi, I'm new here. I'm considering replacing the windows in my home and just from a quick search I can see that there is a lot of things to consider when shopping. I haven't called out a contractor yet because I want to educate myself before talking to a salesman so that I do not rely on him for my information.

I know I'll have many questions before I've made my decision, but I'll just ask one for now:

Are there any notable differences in the manufacturing process between different window manufacturers? For example, I read somewhere that different companies seal the spacers differently. I’ve also read about fusion welding. Can someone who is very knowledgeable on the window manufacturing process chime in and explain to me in as much detail as you can spare the different types of manufacturing methods and give me an idea of which ones you think are superior (and why) and which window manufacturers use which method?

Thanks in advance!

7 things to look for.
Total U -factor of .29 or less on double pane glass. Be careful you are quoted total UFactor and not center of glass.
DP Rating of 50 or higher
Air leakage rate of .09 or lower. Don't let a salesman tell you air leakage isn't important or they just use pass or fail .
Truly welded sloped sill..NOT a snap in sloped sill and NOT a pocket sill.
A non metal spacer, ask for a composite spacer system. Although a true stainless steel is acceptable. Alot of companies falsely claim their spacer is stainless steel when in fact it's a tin plated alloy.
A shgc of between .24 and .30 on double pane glass if you live in the northeast.
Last but not least, quality install.
I noticed most high quality windows have all of these criteria.

In my list I would like to see the following:

1 - U-Factor of 0.28 or below
2 - Air Infiltration rate of 0.10 and below
3 - VT number of 0.50 and above without grids
4 - SHGC of 0.28 or above without grids in a double pane
5 - Sloped sill (welded only)
6 - DP of 40+ (good indication of structure and mil thickness in the vinyl)

All of the above items are moot without a great installation.

Hi thank you both for your replies...both are very helpful. I was actually more interested in how the windows are made in the factory. It's difficult for me to give an example because I'm so new to this, but one example was something I read about super spacer not being as effective in triple pane glass because they heat the glass unit but the center pane doesn't get hot enough therefore the super spacer only adheres on the outer panes not the center. Maybe I'm totally off on this but for example do manufacturers heat the windows? If so, is it industry standard or do some do and some not? Do all manufacturers now fusion weld? I read that Alside's pocket sill windows are all made from one extruded piece.

These are all just an example of what I mean by the manufacturing process. I'm mostly interested in the differences in manufacturing between companies and not so much something that is industry standard. If all windows are fusion welded then I'm not so interested in that but perhaps not all companies manufacture a pocket sill window using one extruded piece? That's what I'm curious to know.

I haven't got to the NFRC values in my research yet, but will be there soon and you guys have given me a head start already

Most vinyl windows are going to be fusion welded, virgin (i.e. no recycled content) vinyl, and sloped sill.

You want a one piece, completely welded sill as compared to a snap in or 2-piece sill.

Sloped sills are superior to pocket because of the potential for issues in pocket sill windows.

Spacers are a bit of grey area. If you ask 10 people the same question, you might get 10 different answers. Most of the spacer systems are well proven and dependable with some of the non-metallic ones have a bit better edge of glass performance.

Overall design and tighter tolerances typically lead to better performance numbers. Lower U-values, air infiltration,etc. Those numbers will tell more about which windows and manufacturers use better manufacturing processes and quality control in my opinion.

In 2008 I purchase the ReliaBilt 7100 Series Vinyl Double Pane Double Hung Windows from Lowes. Lowes also installed them. I think Lowes did a get job with the installation.

I have more windows to replace at the rental. I'm moving back in the rental in April 2012 but I may sell the rental in 2014. So I want to watch my cost.

Should I go back to Lowes and purchase the same windows or can I expand my search to find comparable windows at a lower cost that will visually match the ReliaBilt 7100 Series Vinyl Double Pane Double Hung Windows.

I will be using my own experienced installer this time to save many.

Thanks,

Cathy

Cathy,
Are you the same poster as the original?
Yes you can use a different window.
Like Simonton 5050 or 5300 or soft lite bainbridge or sunrise essentials.

No that's not me

Cathy R

I don't mean to be harsh Cathy, but why even waste your time doing research if you are just looking for the cheapest window that money can buy? If you have your own installer, you won't likely find anything cheaper than what's on the shelf at HD or Lowe's, so you may as well just go get them from there. If on the other hand you are looking for the best value, meaning a high quality window at a good price, you are going to need to start from scratch. Companies like Okna, Sunrise, Gorell, and softlite all have more affordable options than their flagship lines that will still provide great performance and reliability for the long term. Some of them can be found at local builder supply houses like ABC supply, Allied, Richards, etc.
The fact that you have an installer that will actually install them for less than Lowes is a red flag as well, but that's an entirely different topic.

I don't think home sealed is being harsh at all, he's trying to be helpful. Cathy, you are looking for a cheap window and a cheap installation..guess what, I guarantee you will be back on this board in a year or two asking why your windows are warped and why they leak air..I can save you some time and tell you why today..you are trying to by low quality windows and looking for a low quality install.. We all make our own decisions in life and I am quite certain you realize you are doing the wrong thing here.
There is no such thing as finding that one good window cheaper than everyone else and then finding that one talented installer who happens to be be down on his luck due to a bad economy and will do the install cheaply just because he needs the money.. That's a fantasy and it doesn't exist. You get what you pay for in life.