Sorry, double post...

Posted By Lee Dodge on 21 Feb 2012 01:12 PM


I can see that you are not yet convinced that having a high solar heat gain coefficient (SHGC) window in the sunny, predominately heating environment of Prescott, AZ is important. Nor a window with a high visible transmission, since you provide neither of those values. Assuming that those values are acceptable, that looks like a very attractive price.

I never said I was not convinced in incorporating high SHGC windows. I am 95% sure that I will. I just need to make sure that the overhang on the home will be sufficient & the home is positioned accordingly.

The values on that window are:

U = 0.14
SHGC - .027
VT = 0.47 
R Value = 7.1

These are NOT the windows I would use for the passive solar but they are the ones I was able to get a quote. These would be good on the north, west and east sides.

Anyone checked out Intus Windows?

Posted By www.greenss.net on 24 Feb 2012 09:36 AM
Anyone checked out Intus Windows?

Intus Windows are an awesome window and a true triple pane window design. Currently, no American window manufacturer can come close to the engineering and quality of a European window design like Intus. While some American companies like Serious Windows have made better strides.

For instance, an Intus true triple pane window has a U = 0.08 with a SHGC = 0.49, we are talking about R-Values of R8+
That is why European designed windows like Intus can meet the strict European Passive House Standards and windows like Pella cannot even come close.

Any serious passive home energy designer would never use single/double hung or sliders in their design. Those windows have terrible air infiltration/leakage when compared to casement, awning or tilt-in designs.

Maybe one day American manufacturers will set higher standards for their windows but when they are selling Pella and Marvin windows at Lowes and Home Depot, cheap, fast and mass selling is their priority, not energy design.

It's like when GM was pumping out vehicles that were getting 8MPG while other manufacturers were making cars that got 30MPG+. It was not until the gas prices rose and the US Government stepped in and mandated better fuel mileage did GM start to make cars that got better MPG. It will take a serious energy crunch to get American window manufacturers to rethink their business model.

Lbear,
Have you ever heard of Weather shield? Their endurashield can get numbers with a U of .18. Not bad for an american triple pane window.

Posted By peteinny on 17 Mar 2012 09:06 PM
Lbear,
Have you ever heard of Weather shield? Their endurashield can get numbers with a U of .18. Not bad for an american triple pane window.

I will take a look at them. I went to the website and it was partly crashed so I couldn't get any info on the windows...

Be sure you are comparing apples to apples data. European windows are tested at a different temperature and they usually just measure center of glass instead of full frame like American manufacturers. America has better glass manufacturers than Europe.

Posted By EnerLux on 19 Mar 2012 09:37 AM
Be sure you are comparing apples to apples data. European windows are tested at a different temperature and they usually just measure center of glass instead of full frame like American manufacturers. America has better glass manufacturers than Europe.

The European models give both a center of glass rating and a full frame rating, they list them as Ug = U-Value of just the glass, and then Uf = U-value of the frame, and finally a Uw = U-value of the entire window assembly; glass + frame.

The German/European companies that are based here in the USA use either "Guardian" glass or "Cardinal" glass. In the case of Intus Windows, the profiles (frames) are made in Germany by Innoutic, which is now part of Deceuninck, a Belgium company. They are the world’s leader in UPVC (Unplasticized PVC) window construction. As mentioned, the glass is made by  Guardian in the United States.  They are the maker of most glazing you see on large commercial buildings.  The spacers are made by SGG Swisspacers, a Swiss company.

Importing glass would be too costly and the chance of breakage would be very high. So companies like Intus use glass made here in the USA.

As I mentioned before, I've seen the triple pane windows made by companies like Pella and they pale in comparison to German windows. They can't come close to the engineering, frame technology, and energy numbers that European windows can come to. Also Pella's VT is horrendous when you get into the triple pane with a low U-Value. Pella had VT ratings of < .035  Any window that has < 0.40 of VT should NOT be sold as clear glass.

Here in America customers like "doo-dad" windows utilizing single and double hung design. Even though they are the worst in terms of air leakage because of the design, builders utilize them the most in new home builds and Pella is more than happy to keep mass producing those types of inferior windows.

To evaluate the return on investment on imported windows, it is worthwhile reading the blog on the EdgewaterHaus, a PassiveHaus, LEED, net-zero, etc. at http://edgewaterhaus.com/?p=938 .  The blog author looked extensively at window designs and apparently spent a lot of money just trying to see how different windows would fit into his custom house.  He narrowed his selection to Intus and Bieber, and selected the Bieber (http://edgewaterhaus.com/?p=1017).  

After presumably following the approach used on the windows in the design of the rest of the house, he ended up with a cost for the house that was $269,000 more than what the appraiser said that it was worth!!!  He was upset that the bank and the appraiser did not appreciate all of his skilled selection process.

Roger, who writes the blog on his soon-to-be-built EdgewaterHaus, has some sad stories to tell about imported German windows when summarizing his progress over a full year of planning with no construction contract signed during 2011 (from http://edgewaterhaus.com/?p=924):


"After rejecting some early window candidates, we settled on German manufactured, locally distributed Unilux windows in June. Touted as 'exceeding the Passive House standard' in the Unilux sales literature, we were ready to press the Staples 'that was easy button' to fit the Unilux windows into our Passive House. We vowed to tweak the Unilux windows and remainder of the building envelope to attain the PH standard."

"We ran the PHPP software (not an inexpensive proposition) a few times with various combinations of Unilux windows, and by 1 October, we did attain the Passive House standard. Hooah!"  (At least PassivHaus is making some money.) 

"We decided to abandon Unilux windows. Oh, we still like the windows, but after four torturous months dealing with the local supplier and the regional distributor who remained clueless on what our needs were and how to configure Unilux to best meet those needs, we decided that matters were unlikely to improve in ordering, importing from Germany, delivery, installation support, and any post delivery issues. I will share some lessons learned on windows in a future blog."

"We decided with much anguish to defer construction from Fall 2011 to Spring 2012. We had wasted so much time (and considerable money for design and energy consultant fees) specifying the Unilux windows that it was too late to start construction and have the shell completed before the arrival of snow and bitter cold temps. ..."

"Costs kept growing for all aspects of construction. ..."

"To be clear, our window frustrations were the straw that broke the proverbial camel’s back and led us to defer the start of construction to the spring. We desperately wanted to start construction this fall. We would have dealt with the other challenges as they developed."

If you have time and money to spare...

I got a quote from Intus and the windows are only a few thousand more than the inferior and poorly performing Pella triple pane windows. Pella is trying to pass their poorly engineered triple pane window that gets a VT of < 0.35. Any windows less than .40 is not clear glass. To add insult to injury, Pella windows are struggling to achieve anything lower than 0.20 without compromising high SHGC and VT.

I would rather spend $3K more on quality windows than deal with inferior made windows like Pella.

I am still waiting on quotes from other American manufacturers (Milgard, Marvin, etc)



 

We get it Lee Dodge, you prefer leaky single and double hung windows from Pella.

Not everyone wants to live in a square boxed home with single and double hung windows from Pella.

Please find someone else to harass. Your tactics are getting old. I know it's cold up there in Colorado and you might not have anything to do but please stop. Apparently you don't like me or better made windows, so please at least leave me alone.

Pella is trying to pass their poorly engineered triple pane window that gets a VT of < 0.35.

My Pella triple pane windows have a VT 0f 0.60. I selected them for a number of reasons, including that they are a quality product. If I was building a Passive House, I think we might have chosen with different factors in mind.

I think you need to realize that people seek different features in products, and that no one product is going to be the best at everything.

ICFHybrid-

It sounds like your windows will be primarily for passive heating, and presumably for lighting.  Here is an application of (operable) clerestory windows that are used both for winter passive heating and summer cooling: http://greenpassivesolar.com/2010/0...or-center/.  Kind of a bunch of interesting ideas all combined into one building at Zion National Park.   

Posted By ICFHybrid on 19 Mar 2012 09:34 PM

Pella is trying to pass their poorly engineered triple pane window that gets a VT of < 0.35.

My Pella triple pane windows have a VT 0f 0.60. I selected them for a number of reasons, including that they are a quality product. If I was building a Passive House, I think we might have chosen with different factors in mind.

I think you need to realize that people seek different features in products, and that no one product is going to be the best at everything.

ICFHybrid -

The triple pane Pella's with the VT of 0.60 have a U-Value of 0.32 to 0.50, depending on the exact type and series of triple pane window.

If you want the lowest triple pane U-Value window, you get a U-Value = 0.22  SHGC = 0.19  VT= 0.41 - That window is not that great in the VT department and the U-Value is still in the > 0.20 range. Now, if you want a high SHGC in the triple pane, you get a U-Value =0.27   SHGC = 0.49   VT = 55  - Better in the VT department but still you are in a U-Value of 0.27

If one takes an Intus triple pane window and0youI want a window with high SHG, I have the following options:
SHGC=0.49, U-Value = 0.11  VT=70
SHGC=0.62, U-Value =0.11  VT=73

Compared to the Pella triple pane, I get a lot more light with the Intus, an equal or higher SHGC, all while getting a dramatically better U-Value.

For every 0.01 reduction in U-Value equals a 3% reduction in heat loss. The Intus windows offer a 33% - 48% reduction in heat loss over the Pella windows.

The overall frame design, strength, engineering, triple gasket seal design, DP60+ ratings, Swiss made warm edge spacers, etc, make these windows the top of the line.

I hope that Pella does improve its design or some other American manufacturer comes out to give these windows a run for money, but unfortunately for now there is nothing really out there besides Serious Windows that make such a high quality window.

The triple pane Pella's with the VT of 0.60 have a U-Value of 0.32 to 0.50, depending on the exact type and series of triple pane window.

Again, the U-values on my Pella triple panes are 0.29

I think you will find that the passive house type windows don't have the same acceptance among architects who have certain design criteria in mind. That was the case for us.

Posted By ICFHybrid on 20 Mar 2012 01:17 AM

The triple pane Pella's with the VT of 0.60 have a U-Value of 0.32 to 0.50, depending on the exact type and series of triple pane window.

Again, the U-values on my Pella triple panes are 0.29

I think you will find that the passive house type windows don't have the same acceptance among architects who have certain design criteria in mind. That was the case for us.

As mentioned, a 0.29 U-Value window has 54% higher heat loss over a 0.11 U-Value window. Multiply that with 20 or so windows, depending on the home, and you have a tremendous heat loss due to the windows. The same applies in the summer with cooling loads when the A/C is used. Windows account for the 2nd highest energy loss within homes.

I agree that Pella windows has a wider variety of "architectural" designs over most passive window designs but at the same time the passive windows are not lacking by any means in terms of aesthetics. One can always employ creative finishing work like framing the window opening with natural wood if they desire to have the wood appeal.

Especially with ICF or a deep wall design, one can finish the window area with wood:

Lbear,

Are those Intus energy numbers full frame energy values based upon North American testing? Please provide documented proof of how the windows are tested.

What was the test size?

Who is the glass manufacturer and what coatings are used and on which sufaces?

What is the IGU width and gas fill?

Pella uses Cardinal glass and the XL Edge spacer, so it's not like Intus has any better glass. The warmest edge spacers such as Super Spacer only provides an additional 0.01 U Value to the overall performance. Krypton gas will provide 0.02 increase U value at the most over a 1/2" air space with argon gas.

Please provide some documented proof before you go bashing every single American manufacturer. I will agree with you that casement windows are the best. That is why my company only manufactures casement, awning, and fixed picture windows.

Posted By Lbear on 20 Mar 2012 01:54 AM 

Windows account for the 2nd highest energy loss within homes.

According to what I can compute, my windows provide more energy gain than loss in the heating season, and I do not need an A/C system, so there is no cooling energy to consider.  So for those people living in a sunny climate that is heating dominated, do not think of windows as a bad thing, but rather engineer them to help solve your energy problems.  Windows can be a good thing for energy conservation with proper placement, overhang design, and shading.

Multiply that with 20 or so windows, depending on the home, and you have a tremendous heat loss due to the windows

I have a hard time calling it "tremendous" heat loss. Maybe it's relative? Windows are a distant second compared to infiltration in terms of heat loss. Let's say about 20% of your total heat loss. You can go hog wild buying superinsulated windows, but if you even get a 50% improvement in the windows, that translates to only a 10% overall savings and you have to consider what insolation you have also cut off in the process.

If you are spending $2,500 yearly on heat, then your special windows might be saving you $250 a year. Unfortunately, if you have done a good job everywhere else, your heating bill might be only $1,500 or $1,000, in which case the special windows are down to a savings of $150 or $100 per year. What have you given up to get that savings and how much more did you have to spend for them initially?