Do you have a link for the Scenic windows? The Intus is a solidly built window to be certain.

The 350 is a solid window but I don't care for the pocket sill design.

Oberon476 - could you elaborate on thst a bit?

Reasons I've been told and found were European glass is low Iron/clear and thicker.

I wouldn't recommend anything from Pella, ever. I'd recommend going ahead with the Okna quote, as you might find the price to value equation meets your needs.

Ultra - can you support your statement with some arguments?

Have to call around today for Okna window quotes.

Pella's vinyl windows are generally flimsy with poor fit and finish which leads to excessive air leakage and susceptibility to bowing and warping in the heat. The 350 is beefy and much stronger than their other vinyl windows, but they ruined it by incorporating a pocket sill into the design. On top of that, it's ugly.

Pella has always done a much better job of marketing than building windows, as a google search will reveal. The number of total fed-up homeowners out there is quite staggering if you'll spend some time researching it.

Yes I've noticed. I just dint understand the wide and varying array of opinions. From Harvey is the best to Pella is the best provided you get the best in range.

I forgot to add the quote from Harvey (via contractor):

Triple Pane Harvey Tribute: 24,361 - 25 units, installed.

Windows on Washington - The website is www.scenicwindows.com but it seems to be an expired or unclaimed domain name :-/

I have a brochure but can't upload it on here.

On a separate note, I noticed you recommended an OKNA dealer in/for MA on another forum. Would you be able to provide some recommendations please? Not having much luck yet.

WoW - I called the company and was advised that they're in the process of getting the website online. Have a call with them later today.

I have an issue with a company that doesn't have a website in the year 2015. Even a crappy site is better than nothing in my opinion. And being in the process of "getting the website online" sounds a bit strange to me. That and there are no reviews on Google unless you are in the UK would be the next red flag.

Transnational,

About what region is the home in? I will point you towards in the right direction based on that.

We refer to it as Metrowest area. About 10 miles south of Nashua, NH.

transnationalq,

If I was consulting with you on a glass package my first question would be what do you want to achieve? High solar heat gain? Solar protection? Windload requirements?

What's more important to you, lower U value or higher (or lower) SHGC?

In an apples to apples comparison there is no advantage to either Euro or North American glass. You did mention low iron and thicker glass in Euro windows, and they both can be an advantage depending on your requirements, however you can find both in North American windows as well; and don't think that low iron is a standard in Euro glazing, it isn't, it's an option just as it on this side of the pond.

Oberon476 - The SHG is something of a vague and uncertain area. I'd like not to lose VT, and have low Uw values. We're in Massachusetts - summers are hot and humid, winters and cold and dry with snowstorms not being unheard of but it is not tornado country.

I've attached a rather rudimentary sketch of the orientation of the house. What kind of SHGC would serve us well in this orientation and climate? This house at best will have much improved insulation and air sealing (currently none) but not anywhere near passive standards. We're hoping also to achieve a good level of sound insulation being that we are on a corner plot and the living room, dining room and two upstairs bedrooms are on the side of a somewhat busy road that serves as one the main arteries in and out of town.

I'm currently thinking of changing my windows so searching for a good company with qualified products. You can try to visit web site, I like that what I've found here...

Canadian spam. Delicious and thicker cut.

What does that comment make you Ole Joe bob? Kindly stop trolling this thread if you can't add any value.

OMG, how rude Ole joe bob Billy bob! I suppose man shouldn't behave like that... And actually I thought this is a proper thread to tell about a window company, as transnationalq asked, isn't it?

Its hard for people on the internet, even experts, to make specific recommendations when there are so many site specific details that affect window performance. Your orientation diagram is useful but open to interpretation. There is still building shape, landscaping and overhang designs that needs to be accounted for. An ENERGYSTAR certification or other third party energy rater could help you with these decisions as well as verifying the home is properly air-sealed and insulated.

If the window installation leaks even small amounts of air, the Ufactor becomes less meaningful.

As stated before, the home must be orientated correctly, have the right amount of glazing, right type, as well as the proper thermal mass absorbing materials on the inside of the home.

When it comes to passive solar design considerations, I think thermal mass is over rated. Amount of glazing, orientation, shape and overhang shading are where to focus efforts. More thermal mass may help, but its cost-effectiveness is always in question and it could hurt comfort by slowing down thermostat response.

I'll agree with you Springtime Builders. There is a certain style of house where thermal mass is going to matter but the right kind of glass in the right location is important for every kind of house for optimum light and heat gains. U values will ensure minimal loss of heating/cooling.

Replying to your earlier comment Springtime Builders - our house is a straight and simple old colonial. No fancy designs. No overhangs. It is difficult but I tend to send photos of the house with orientation and whatever details might help a supplier make a suggestion but truth is, I have not come across a supplier who will talk about this in great detail. They're selling a certain window with certain specs so they will most likely just reiterate the specs on those along with their advantages.

They can't do much when I say but the VT value is pretty low or I'd like a slightly higher SHGC.... What should I expect from them anyway if none of their products meet the specs in the way I would like. Nothing I guess. It'd be the same when I find a window that tempts the socks off me with specs but falls outside of budget. Its my problem, not theirs. It is what it is.

It'd be nicer to work with someone who worked with a wide array of windows with varying qualities and options in Uw, SHGC, and VT but unless I go to a custom window builder I don't see that happening.

Springtime...can you explain the shape point you highlighted above. What does the shape of the glass have to do with anything? Orientation, square footage, glazing type, and shading all make sense, but what does shape have to do with the realized passive solar that isn't addressed by the previous three (size, shading, and facing)

Notice that I mentioned thermal mass as 1 of 4 things when it comes to passive solar maximization of effectiveness. If the home has good Southern exposure, and the area that would most benefit is covered in light colored carpet, you are not nearly maximizing your effort. I lump color of interior materials into the thermal mass equation. I think we can all attest to the differential temperature that is observed in a darker substrate vs. a lighter color substrate. Ask a person to walk on concrete in the summer vs. asphalt and ask them if color makes a difference.

At the end of the day, you can retrofit the home so that it can be heated with a candle if you like. The question is whether that retrofit will pay for itself. The same question goes for the differential expense of a custom window and glazing vs. the more universally accepted practice of Low-e. I know you are a researched, but I think you are approaching analysis paralysis. It is a condition that I often suffer from so I am speaking from expertise.

Unless you can tell me that your home has been air sealed and insulated, the windows (whatever custom version you get) won't even approach the saving or payback ROI that you would realize from that.

Most vendors won't talk about passive solar or any more depth about VT because they don't know. Better to have them not talk about it as compared to make something up.

For 10 points on VT as compared to clear glass, I am opting for Low-e all day long. I roughly doubles the thermal performance of the unit and while it does cut down on SHGC, it is easily recouping that expense in kind by dramatically lessening the rate of energy movement out of the home through the glass. Summertime cooling will also see a benefit.

For the sake of argument, lets assume your home has about 15% window to 85% wall exposure. That is pretty light as compared to many homes, but you mention the home is older. As far as window types, lets compare a clear glass, double pane, argon filled equip window with a U-Factor of 0.45 (that might be generous) and the same window with Low-e and a U-Factor of 0.27.

So, we have used the math that favors the clear glass in both the area of the windows and the performance and downplayed the performance of the Low-e window.

Guess how much more efficient the entire walls system (i.e. all the walls and windows average together) of that home is with the Low-e window......? 25% more efficient. The ENTIRE WALL system (windows and walls averaged together) is +25% more efficient with the windows with Low-e. Unless you can demonstrate how the home is set up for Passive Solar to take advantage and try to make up the delta, the Low-e window is going to be more efficient.

Now...if you don't like the tint or the hue of the windows...these are aesthetic questions that cannot be answered via spreadsheets and numbers.

That comparison above was for clear, non Low-e glass. I am aware of the other glass options aimed at maximizing SHGC and still having a Low-e coating. There is no magic bullet though. What you gain on SHGC does come at the expense of U-Factor points. Cardinals Low-e 180 is a good coating and does a good job of balancing the two. Still costs you 20 points over clear glass on SHGC.

No problem Wow, I meant the shape of the house in relation to the southern exposure. Decks and covered porches negate most heating for levels of windows below them and jogs or bumpouts have the effect of shading the windows next to them depending on the time of day which I try to illustrate in that passive solar blog.

The problem with carpet is it's insulating effect, not the color. Slabs on grade is where cost-effective thermal mass ends to me and it should be kept exposed or tiled in areas of direct sunlight for best effects. Thermal mass and it's color gets hard to model and measure while the window stuff is much more influential.

I agree with taking lower VTs for better energy performance but not sure about using it as an energy performance metric compared to SHGC. For homes that pay attention to passive solar design, its easy money choosing low-e, high SHGC windows for the best, year round energy performance in mixed and heating dominated climates for the south sides of the home. Its the most cost-effective way to heat a home or building.

Just a brief reply for now....I'm not shooting for passive house standards. The journey there would be a long, arduous and expensive one with a possible pay back of 20 years which I'm certain we won't stick around long enough for.

The matter of VT, and SHG with a low U value remain significant though. Why give up free heating? Why give up natural light?

Yes, the tint is aesthetic and no maths can justify it. It could just be a matter of time before I relent.

I like the 'analysis paralysis' bit! I'm definitely feeling it. I'd rather decide based on having explored all options thoroughly and come out wiser if a bit time poor. :-)

Numbers are the numbers though. If the home isn't set up for it, it just isn't. I get the feeling about the tint and reduction is passive solar, I just don't think the numbers will bear out that your investigation will net anymore efficient home.

If it isn't air sealed and insulated...start there. Leave the window decision for a later date.

Thanks Springtime. I see what you are saying. Shape, at that point, seems to be redundant of the other descriptors you previously mentioned. Orientation and square footage seem, to me, to encompass the shape question, but I see what you are saying in terms of building design.

It's going to have insulation and air sealing done - courtesy MassSave. No point in putting off decisions for one thing based on another. The work has to be staggered over time as everything from ordering to action has mounting lead times.

Yeah, shading should encompass all, but can mean many different things that affects performance: overhangs, landscaping, shape facing south, and exterior or interior shutters or blinds. Exterior shading is most effective. I see shape facing south as a different performance criteria than orientation and square footage but they are certainly related.

Transnat and others, be aware of the difference between passive solar design and passive house certification. The german originating (and now US version) certification is like a super strict version of Energy Star although they often include some amount of passive solar design. Passive solar design is mostly about window placement and SHGC selection to achieve free heating with the sun.

In my experience, specifying low-e high SHGC glass for south windows rarely costs that much more. On a window quote I just got today, the supplier said that Cardinal's passive solar glass,LoE180 added 3% to the window price which is likely paid back in heating performance the first year in our mixed climate. It was still less than Cardinal's 366i89 option and ive seen the LoE180 come in the same as regular lowE offerings before.

My point was not to put off one project in lieu of another. Just that the Air Sealing and Insulation will definitely save you more and if you are in a conundrum about which glass/window to go with, give you something to start with of some impact before the colder temps set in.

I do agree that higher SHGC can be usually be specified for cheap. The question is whether a given manufacturer orders their glass or makes it in house. If they make it in house, most folks do not keep a multitude of glasses on hand. If you find someone that keeps more than one type of glass on hand, it usually a medium and low SHGC for the warmer climates.

I guess it depends how you define a certain criteria. Shading, orientation, and square footage seem to cover all the variability in my mind, but I do realize you are doing this on a daily basis and probably use terms that have recognition with client. Makes sense.

transnationalq ,

You are the beneficiary of an excellent discussion here. Both entertaining (for a nerd like me), but also very informative.

In all cases LoE coated glass in a window is preferable to non-LoE coated glass for energy performance, but what LoE to use?

Here is an interesting quote from Dr. Joe Lstiburek, principle of Building Science Corporation (https://en.wikipedia.org/wiki/Joseph_Lstiburek):

"Don’t bother with the passive solar. Your house will overheat in the winter. Yes, you heard that right. Even in Chicago. Are you listening Passive House? You should go with very, very low SHGC’s, around 0.2, in your glazing. If this sounds familiar to those of you who are as old as me it should. We were here in the late 1970’s when “mass and glass” took on “super-insulated”. Super-insulated won. And super-insulated won with lousy windows compared to what we have today. What are you folks thinking? Today’s “ultra-efficient” crushes the old “super-insulated” and you want to collect solar energy? Leave that to the PV." -- Joe L

Personally, I happen to like passive solar simply because it feels good in the dead of winter and I would use 180 on my south-facing windows, however and speaking of passivhaus, the Germans (specifically Dr. Wolfgang Feist) do promote higher SHGC, but they do it because of comfort and not specifically for energy performance.

I am most grateful to everyone who has contributed to this thread and discussions on windows. Ran in to an ancient thread of your's elsewhere and was interesting to see how a decade of conversation had progressed.

You quote about low SHGC. I had the opportunity to meet a very passionate custom windows guy today in his 'shop' here in Massachusetts. As much as I like a high VT and midrange SHGC, this chap was adamant that it just did not work for New England climate and also supported mid 0.2 to mid 0.3 SHGC values.

I'd be interested to see if persons with certain installed spec windows would share their experiences. Orientation, shading would play a role as well but it'd be interesting to learn about their experiences.

Got to reading about LoE coatings a few nights ago...still in the learning phase. :-)

Oberon,

Leave it to Dr. Joe to lay it out in plain English. I am surprised he didn't work in a more colorful term in there somewhere.

Happy researching transationalq. There is plenty to read and you have a fantastic resource in anything that comes out of Oberon's brain/keyboard as well.

Here is the Building Science Corporation page with Dr Joe's quote, Zeroring in. Here is a Green Building Advisor thread where a poster questions using High SHGC glass based on Dr. Joe's comment.

I take most of Dr Joe's writings as gospel but this paragraph deserves much more elaboration than simply dismissing all passive solar design. I think (but you would have to ask the good Dr) that he is dismissing passive solar in favor of super insulation which I agree with. Good insulation with verified airtightness is far more effective and important than passive solar design.

Dr Joe writes for the masses. The masses ignore orientation and proper shading for windows. Low SHGCs everywhere are certainly the best choice when orientation and shading are ignored.

Good passive solar designs in mixed or cold climates rarely overheat in the winter. It's the fall and spring when they generally experience overheating, not winter.

South-facing window to floor area is the main criteria for avoiding overheating, not SHGC selection on south facing windows. In mixed to cold climates, energy modeling, including passive house, suggest that south-facing windows with proper shading, provides better energy performance with high shgc glass.

Passive solar designs are less comfortable, mainly in the late fall and early spring during warm weather, when properly sized overhangs are being bypassed by the lower track of the sun. In my experience, and most other's feedback, passive solar designs are much more comfortable overall than homes that ignore passive solar principles.

This GBA article that Martin points to in the above thread is a good one for those going after net-zero optimized thermal performance considering south-facing windows. Still, houses need windows and the energy performance of those windows are improved by good passive solar design, which includes choosing an appropriate amount of south-facing, high shgc glass with good shading.

Probably makes better sense at this point to start a dedicated thread to Passive solar for future readers. For the previously well established reasons (orientation, shading, shape, mass, etc.) most homes don't comes close to approaching the effectiveness of passive solar. Based on transnationq's drawing of her home and orientation, I am not sure it fits there either. Your website demonstrates the importance of shading as well and how that must really be worked into the design. Most of the track built construction (also the same people using the windows that require replacement) takes none of that into question and putting something of moderate SHGC on the home will not deliver the performance they are looking for. I still think, for a majority of the homes North of NC, triple pane is the proper option. Obviously that depends on the price of the upgrade, but triple pane glass will give them the better solar control in the summer and deeper insulation values.

I agree. Shame all this stuff will probably end up buried. Hoping triple panes continue to drop and how come exterior shutters aren't as popular over here? Seems like all new construction in Europe had them and they were great. For that matter, hurry up with the SHGC that can change depending on the season.

Springtime - I agree about external shutters. Not only great for blocking out strong sun/heat but great for avoiding crazy early morning sun and late sun when getting the kids to bed :-)

I think the thread will probably turn up in searches...all will not be lost.

I'm waiting on radiant windows and integrated solar solutions.

Odd, I thought I had included the link to the complete GBA thread as well...oh well, thanks for posting it, Springtime Builder.

As an amazingly appropriate follow up to that thread, and a heck of a read (including links to a couple other interesting blogs), this is worth checking out!

http://www.greenbuildingadvisor.com/blogs/dept/musings/gba-prime-sneak-peek-reassessing-passive-solar-design-principles

Timely GBA post indeed Oberon, thanks I hadn't seen it yet. I just posted a lengthy comment and glad to see other commenters there with experiences similar to mine.

Martin usually offers these subjects in an interesting manner to create response and conversation. Did you notice he didn't title it "Passive solar design is dead"? Based on the response he got from Solar thermal is dead and its sequel, I bet he wanted to really bad!

I think this one is more appropriate for the OP....

http://www.greenbuildingadvisor.com/blogs/dept/musings/study-shows-expensive-windows-yield-meager-energy-returns

That's the one I linked to on the bottom of Oct 3 that Oberon was probably referring to. It's about a study that looks at the cost-effectiveness of adding south window area to net zero projects in Canada. Be sure to read the comments before making any judgements about passive solar design or expensive windows. Windows are often seen as an energy saving investment but there are many more considerations involved besides upfront costs and energy performance. I think windows are one of the best places to invest in quality products even if some studies suggest they don't pay back in energy costs compared to solid wall area.