Performance and Price

For all those Replacement Window questions
Post Reply
Message
Author
TMFE
Posts: 10
Joined: Tue Aug 30, 2011 10:30 am

Performance and Price

#1 Post by TMFE » Thu Sep 22, 2011 10:05 am

Will I see a difference between the following differences in the window specs, enough to pay a higher price point? Which is more important U value, SHG, or air leakage?

U value:
1) Window 1: 0.30
2) Window 2: 0.30
3) Window 3: 0.28

SHG:
1) Window 1: 0.30
2) Window 2: 0.29
3) Window 3: 0.27

Air leakage:
1) Window 1: 1.13
2) Window 2: 0.07
3) Window 3: 0.05

The U and SHG values between all three windows are pretty close. However, the Air Leakage values has the highest difference between window 1 and the other two windows.

Will you notice a difference between an Air Leakage value of 0.07 and 0.05? Is it worth an increase in price.

How much of a difference will I feel between an air leakage value of 1.13 and the other window values of 0.07 and 0.05?

I'm considering Window 2 and 3, but wasn't sure if the small difference between the U, SHG, and Air leakage value is enough to really feel a difference in the performance.

And also with Window 3, the U and SHG is pretty close, but not sure if the high air leakage value (1.13) will really effect the performance of the window.

Please advise.

EcoStar Remodeling
Posts: 210
Joined: Thu Jul 28, 2011 5:28 pm

Re: Performance and Price

#2 Post by EcoStar Remodeling » Thu Sep 22, 2011 10:15 am

Any particualr reason you won't disclose the window brands, the price and where you live? Those are all important factors. Blind posts like this usually don't get a very good response, at least one that has any real value. How do you expect an answer as to whether something is worth the additional price when you haven't included any pricing information?

Sounds as if you are trying to justify a lower cost window and somehow you think performance numbers alone will allow you to do that. A Lexus that gets 18 MPG has a greater value than an Dodge that get 25 MPG.

User avatar
HomeSealed
Posts: 2402
Joined: Tue Feb 16, 2010 6:14 pm
Location: Milwaukee, Madison areas
Contact:

Re: Performance and Price

#3 Post by HomeSealed » Thu Sep 22, 2011 11:27 am

I do agree with Eco's points, as performance #'s do not tell the full story. A window that is designed and constructed better than another could conceivably have the same #'s (or even worse in some cases), but the superior window will retain its level of performance.
Based on numbers alone, you won't feel any perceptible difference between the three. As to which number is most important, I would say the U value, although all three are important in the fact that they reflect different areas of performance. You could have the best U value in the world, but if the window leaks air like crazy it will not perform well, and the same could be said if you reverse those two. All three of them are close enough however that any difference that you could/would experience will be more likely due to the overall build quality of the product, as well as the installation.

randy
Posts: 1010
Joined: Tue Dec 20, 2005 11:27 am
Location: Houston, TX
Contact:

Re: Performance and Price

#4 Post by randy » Thu Sep 22, 2011 11:37 am

Did you mean to say AL rating of 1.13? Normally, I would assume that you meant .13, but since it was written twice in the post, I thought I'd ask. AAMA requires a window to be rated at .30 or below to obtain AAMA certified.

You would absolutely notice a difference between .07 and 1.13. Between .05 and .07, probably not.

TMFE
Posts: 10
Joined: Tue Aug 30, 2011 10:30 am

Re: Performance and Price

#5 Post by TMFE » Thu Sep 22, 2011 11:42 am

Correct Air Leakage is 0.13. Sorry for the confusion.

TMFE
Posts: 10
Joined: Tue Aug 30, 2011 10:30 am

Re: Performance and Price

#6 Post by TMFE » Thu Sep 22, 2011 11:50 am

Thanks for helping me have a better understanding about performance ratings. So at the end of the day, the quality of how well the window is manufactured will determine if the window will continue to perform at the same U, SHG, and Air Leakage value down the road (2, 5, 10 years+).

I understand that installation is a HUGE factor in window installment.

I've researched a lot about installation. But I've read different recommendations when it comes to the type of installation that should be used.

I've read that Expanding Spray foam, if not used properly could expand too much and cause air leakage. I've read that if the installer doesn't use SHIMS that the window will begin to settle and leak air in a year or two after the installment.

Do you have any advice as to what is the proper way to install a window, the caulk that should be used, if shimming is an absolute must (no matter if the window is a tight fit, less than 1/8th of an inch, etc), and the type of installation that should be used?

randy
Posts: 1010
Joined: Tue Dec 20, 2005 11:27 am
Location: Houston, TX
Contact:

Re: Performance and Price

#7 Post by randy » Thu Sep 22, 2011 11:59 am

Tell us more about the installation. Also, what part of the country are you in?

1) Type of window being replaced - aluminum, vinyl, wood.

2) If wood windows are being replaced, are you doing a full frame replacement?

3) If aluminum or vinyl windows are being replaced, what is the exterior cladding material - brick, siding, stucco.


To answer some of your questions. Yes, if expanding foam is not properly applied, it could cause more air leakage. It could also void the warranty on the window, cause the jambs to be so compressed against the sashes so as to restrict operation, and it could lull the installer into such a false sense of security that he neglects other important steps. Having said all that though, properly applied minimal expanding foam is absolutely the very best way to insulate and seal the perimeter of a replacement window.

Ordering windows so tight that there's not 1/8" gap around the perimeter is not wise and can, in some cases, void the manufacturer's warranty.

User avatar
HomeSealed
Posts: 2402
Joined: Tue Feb 16, 2010 6:14 pm
Location: Milwaukee, Madison areas
Contact:

Re: Performance and Price

#8 Post by HomeSealed » Thu Sep 22, 2011 12:22 pm

I agree 100% with Randy that low-expansion foam is best. The likelihood of it causing any issues when the proper material and procedure is used is slim to none. As for shims, they are generally recommended. The circumstances of an individual window installation will really dictate the if, where,and how many. The hardened expansion foam will also act like a shim to some extent, essentially locking the window in place.
Some of your other question depend on the details of the project as Randy alluded to.

TMFE
Posts: 10
Joined: Tue Aug 30, 2011 10:30 am

Re: Performance and Price

#9 Post by TMFE » Thu Sep 22, 2011 12:25 pm

Thanks Randy.

I live in Woodbridge, Virginia (30 minutes South of Washington DC). I'm replacing wood windows with Vinyl windows. The front side of my house is brick and the other two sides are Vinyl siding. I have 4 windows that are 102 cubic inches and the other 8 are under 102 (I can't remember the cubic inches, but I know they are much smaller).

I will be doing a full frame replacement.

Is there a specific type of expanding foam the installer should use or request the installer to use?

randy
Posts: 1010
Joined: Tue Dec 20, 2005 11:27 am
Location: Houston, TX
Contact:

Re: Performance and Price

#10 Post by randy » Thu Sep 22, 2011 4:31 pm

Some contractors prefer the old fashioned method of using fiberglass insulation around windows. The problem with this method is that fiberglass is not an air OR moisture barrier. Using fiberglass insulation only helps if the cavity around the sides of the window are completely sealed, so as to be airtight. This is typically not easy to accomplish, and therefore, foam is superior.

As to the type of foam, there are numerous brands that will work just fine, so long as it is a polyurethane, closed cell, minimal expanding type.

I would respectfully suggest that you let Windows on Washington come out and show you his installation process and products. There's just really no one better in the DC area. Under his name, on one of his posts is a "get a quote" button that will get you to him, and only him.

He'll cover everything that I have and far more, since he can see the job. I have no doubt that he will stand heads and shoulders above the other companies you've spoken with.

TheWindowNerd
Posts: 1675
Joined: Sun Feb 22, 2009 5:52 pm
Location: SE PA & NJ; CT
Contact:

Re: Performance and Price

#11 Post by TheWindowNerd » Thu Sep 22, 2011 5:48 pm

+1 for WOW

Post Reply