Schuco NFRC Values

[tgtrim]

I have been reading and learning much about vinyl replacement windows over the last few months through this discussion board and other sites and thought I was ready to make my window purchase. As it turns out, I was not as ready as I should have been.

About three months ago I started shopping around for replacement windows and after a few quotes and alot of reading on this site, I decided on Schuco windows. Approximately six weeks ago, I signed a contract with the Schuco salesman in my area for 1 picture and 13 double hung windows. The salesman pointed to the 0.22 U-factor in the brochure and told me I needed to purchase the Corona 4000 Vinyl window with triple glazing, Krypton gas, and Low E2 coating to get windows with that exceptional rating, so I did. Schuco does not have the entire set of NFRC values for this window on their website, so I went to NFRC.org to obtain the remaining numbers. What I found was what I belived to be the correct set of values which were 0.22 U-factor, 0.27 SHGC, 0.36 VT and 63 CR for the window recommended by the saleman.

Two days ago, the windows arrived but to my disappointment, the NFRC ratings were not what I was led to believe. The numbers on the NFRC label read 0.29 U-factor, 0.34 SHGC, 0.45 VT and 55 CR, which are significantly different. According the the NFRC website, these values can be obtained on Schuco double pane windows with krypton gas so I verified the windows were triple pane using the candle flame method. I immediately called the salesman who told me to let the installer continue because the sashes could be exchanged after the installation if need be and he would get on the phone with Schuco to find out what happened. I received a call later in the day informing me that the numbers on the NFRC label were indeed correct for my windows because they have Low E2 coating on only one window pane and that I needed to have purchased Low E2 coating on 2 panes to get the lower values. I was in shock when I heard this because it is not listed as an option anywhere in Schuco's literature and I was not informed of this by the salesman during the contract signing. Is this true? If so, why is it not listed as an option in the literature? The salesman also told me the cost for the second Low E2 coated pane would have been significantly higher. How much higher could it be? I guess that is not really important now.

Anyway the installer finished yesterday and I had to pay him the balance due from the contract since the NFRC label also listed Vertical Slider Corona 4000 Vinyl window with triple glazing, Krypton gas, and Low E2 coating on it which is exactly what was on the contract. Legally, I could only hold back 5% of the balance as stated on the contract (fine print). If I had to do it over again I would have listed the NFRC values as part of the contract. It never entered my mind to do that. Shame on me I guess.

Can any of the other Schuco dealers/installers on this board help me out on this one? I need to understand what is fact vs fiction so I can go back to my salesman with intellegent information. The way it stands now, the salesman is going back to Schuco to see what they can do for me. At this point, I do not expect to hear any good news, if I hear anything at all.

I thought I was paying for the best window Schuco had to offer but I received something less. Although the NFRC numbers on the windows I have are not bad, I feel I could have done just as well with another window company for less money. I wanted the best performng window from the best window company and that is not what I have.

Thank you for taking the time to read my very long post (Sorry about that) and for any responses that might be forthcoming.

Tom

[Delaware Mike]

Tom,

Only one time have I ever had one of my Schuco customers who had done a lot of online research specifically request that glass package that you wound up with. She had her reasons so I didn't push the issue.

I wonder what the sales guy considered to be that much higher? I would think that $700 would be about the total differnence between the two not knowing this particular companies' price structure. That would be on the high end.

I really hope this is an honest mistake. I know of one company that once used to pass off Sungate 100 as Solarban 60 to save a nickle.

[Window4U (IL)]

If a salesman told you specifically that you were getting a window with a U-.22, then that is what you should have gotten.
My guess is that a mistake was made on the order sheets. Triple with 2 panes low-e is a #406 glass package, and with one coat it is a #405.
If they did make a mistake, I hope they take care of it for you.
Good luck.

[researcher]

I find this odd; why even have a #405 package available? It does not make much sense to me.

[tgtrim]

Delaware Mike and Window4U:

Thank you for your prompt replies. I am still waiting for a return call from the sales guy. It seems like it would be easy to make a mistake on an order for a #406 package and end up with a #405 package instead (handwriting, typo, human error, etc). I am still hoping for a good result but I am not optimistic.

Researcher:

I agree with you. If the double pane, krypton, Low E2 windows have the same 0.29 U-factor, 0.34 SHGC, 0.45 VT and 55 CR values (SCH-M-16-00058-00001 on the NFRC site) as the triple pane, krypton, low E2 on one pane windows (#405 package), why spend the extra money on the third pane? It does not make sense to me either. Other than sound level, can anyone see an advantage to getting the #405 package over the cheaper double panes?

Tom

[Window4U (IL)]

I find this odd; why even have a #405 package available? It does not make much sense to me.

I'm guessing it would be used in a solar heating project for allowing more solar gain.

The Schuco glass packages available are:

Double pane with no low-e or gas #003
Double pane with low-e /argon gas #405
Double pane with low-e /krypton gas #405
Triple pane (1 piece low-e glass) /argon gas #405
Triple pane (1 piece low-e glass) /krypton gas #405
Triple pane (2 pieces low-e glass) /argon gas #406
Triple pane (2 pieces low-e glass) /krypton gas #406
These packages are all available, but individual dealers may choose to not include all of these in their own price books and lineup. Some dealers only offer one or two.

Just curious, what part of the country are you from tgtrim?

[researcher]

tgtrim

I think you will may find this interesting, It was written by Oberon in a different forum.
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BestValue, as a general rule, a triple pane will not significantly improve sound performance over a dual-pane IF the overall airspace is the same on both types of IGU.

The Canadian study referenced by Stephen Thwaites is an outstanding resource and I highly recommend that anyone who is interested in sound performance read it...I happen to have a hard-copy of that report in my book of "cool-stuff".

In that study you will have noticed that there are situations where a single lite of glass will actually outperform (sound) a dual pane IGU at certain frequencies. You may also have noted that the dual pane IGU in that example had a 1/4" airspace between the lites. It is the width of the airspace that is significant in that example.

Without going into lots of formulas and calculations, the 1/4" width of the airspace can actually enhance the transfer of specific frequencies thru the unit - this has the effect of actually limiting the effective sound attenuation in that particular make-up. Basically, the wider the airspace in the IGU, the better the overall sound performance...1/4" airspace is not the best for sound attenuation.

As pointed out in the reference, a triple pane with two 1/4" airspaces will have the same STC as a dual pane with a single 1/2" airspace. The potential advantage of the additional lite in the triple pane is off-set by the disadvanatge of the narrower airspace between the lites.

All of which brings us to your original post. Often (almost always) posts asking about sound and the difference between dual pane and triple pane performance simply discuss triple pane versus dual pane without regard to the actual make-up of the units. Your post was different in that you actually listed what the actual width of the airspaces are....we can use those numbers to draw some very general conclusions (not specific conclusions though. Your actual situation and circumstance would have to be evaluated before any sort of precise values could be assigned).

The IGU width (I am assuming airspace and not overall thickness) of the dual pane is 3/4". That is a rather common IGU set-up and is certainly acceptable in terms of both energy and sound performance.

But, the triple pane airspace widths are a very nice start in establishing sound perfomance criteria. The casement has an overall airspace of .96" and the triple pane fixed is 1.084" overall airspace width...nice numbers when dealing with residential sound issues. The typical dual pane versus triple pane argument really doesn't apply in this case because of the differences between the triple and dual IGU's.

There is some truth in the salesman's concerns about using two different thicknesses of glass in the IGU. Window glass does flex. It bows and twists and moves with changing winds, barometric pressure changes, thermal stress...etc. There are advantages to having the same thickness in the various panes of an IGU when dealing with these stresses.

Barometric pressure changes, for example, can cause the glass in an IGU to bow concave or convex depending on the high or low of the pressure. It is preferrable to have the panes bow by the same amount so as to avoid over stressing one lite over the other. In other words, if the lites are the same width, they will generally mirror one another's movement.

But, if the lites are different thicknesses, it can put more stress on the thinner lite to bow more than does the thicker lite - under the same stress. In the case of unequal thickness lites, the thicker lite may even bow less than it would in an even-lite-thickness situation forcing the thinner lite to assume a greater percentage of the stress.

Is it a potential problem? Again, like so many issues, it can be very dependent on the specific environment. In the SF Bay area, and using 3mm and 4mm glass (and not thinner), I would consider the risk to be minimal.

As always, install is vital. Even more so when you want to eliminate sound problems. Also, remember that your walls can also pass sound energy, or anywhere that air can leak into your home, sound will use the same access points. Sound is efficient in finding any weakness.

Make sure whatever windows you purchase are tight. A loose window will pass every sound imaginable.

And, as mentioned by several other folks, laminated glass is definitely always an option. In addition to sound attenuation, laminated also offers security from unwanted visitors and it stops 99% of UV from passing thru the window.

And, finally, since you are concerned about railroad noise, there are several government studies concerning railroad and airport noise and noise abatement available. I am not sure if they are available to the general public (although I don't see why they shouldn't be). They do tend to be very technical with lots of charts and graphs and numbers and stuff but they do have a lot of very good information on how to keep that sort of specific noise out of a house.

[tgtrim]

Researcher:

Thank you for the sound level post. After reading it, I believe it is possible that the triple pane windows do not carry a noise reduction advantage over the double panes. So again, why carry the #405 package?

Window4U:

Thank you for the package info. I live in on a heavily wooded lot about 30 miles north of Philadelphia, PA. Maybe the salesman was thinking I could use the additional solar heat gain in the winter when the leaves are off the trees and light in the summer when there is an abundance of shade. That being said, he still should have informed me of the difference in the energy values and offered me the cheaper dual pane package with the same energy values. Either my salesman is not fully educated on the Schuco line or there is something sleazier going on.

To other Schuco dealers on this site:

Have you ever sold the #405 triple pane package to any of your customers and if so, what were the conditions that existed to prompt the recommendation? I am still trying to wrap brain around all of this and would appreciate any information you guys can offer.

Thanks,

Tom

[Delaware Mike]

Tom,
Our one #405 customer had been concerned about how much darker the house would be with two panes of glass have the low-e coatings on them. She was worried about losing too much light. Her home is right off of 76 close to Villinova University. I mention this only because I didn't see the need for the triple glazing if she wasn't going to go for the #406 as she was comparing the cost of our Schuco windows to the local Renewal by Andersen proposal that she had gotten before we came out.

They were so high that anything that we did we looked like a bargin. She opted for internal grids, thus I wanted to go double with the nicer contour grid, but she wanted to stay with the triple? If the overall U-factor was about .26 I could understand this, but at .29 it doesn't seem like a good economic decision over their double-glazed low-e with argon.

[FenEx]

tgtrim

If you verified by a candle test that the units are indeed triple pane... I think you are simply a victim of improper NFRC sticker application by a factory worker. The highest U-factor listed for a Schuco Trip on a verticle slider is 0.23. Sounds like they placed a double-pane sticker on the products by mistake. A second pane of low-E would not drop the U-factor by 0.07 by itself in a triple-pane, krypton gas filled unit.

[Window4U (IL)]

Good catch FenEx.
It didn't dawn on me to check the NFRC numbers on the triple with one layer low-e. I wasn't aware of the numbers since I've never sold that package and took it for granted the stated numbers were right.

Ptgtrim, put the lighter down and just look at the spacer. Do you see a thin line running down through the middle, or does the spacer look smooth all the way across?
Like FenEx said, you either have mislabeled windows, ....or you have double pane instead of triple pane.

[tgtrim]

Fenex and Window4U:

I really hope you guys are right. It would make me feel much better about the whole window buying experience.

In addition to the three candle reflections, I did see a thin line running down through the middle of the spacer and the grids look like they only come half way across the spacer, which I think verifies the triple glazing.

Now that is highly probable that the values on my windows are incorrect, would it be possible to post what the NFRC values should be for the #405 window package. I talked to the salesman earlier who verified that is what he ordered for me. I tried to look the values up on the NFRC site but I could only find triple pane with 2 panes Low E2 coating listed.

Thanks guys,

Tom

[researcher]

You could have the salesmen bring to your home his sample triple pain and a heat lamp so you can compare his sample to the windows delivered; you would feel more heat getting through a 405 package. You may even see a difference just looking through the two as the 405 will transmit more light. But i think the heat lamp test would more obvious. And also make sure that his sample is indeed a triple pain.