Hi snowlover,

I agree with Mike in that it really depends on your requirements. There are a few differences that I will discuss - if you have a minute (or several).

A dual pane window with a LowE2 coating and argon gas will outperform - energy considerations - a triple pane window made with clear glass.

The real advantage of a triple pane is that since there is that extra glass layer the manufacturer has the ability to coat two different surfaces with the LowE2 coating.

As a general rule, triple panes come in two varieties - one version has a relatively narrow space between the lites - kind of like taking a wide dual pane and dropping another lite between the first two.

Then there is the triple pane with a wider spacing between the lites - kind of like taking two "standard" dual panes and removing a lite from one and slapping the remaining parts together.

Both work, but there are some differences worth considering.

The narrow airspace version works best when two surfaces are LowE2 coated and krypton gas is used between the lites. Krypton gas performs at its energy-saving best in a narrow space of about 1/4" or so...which happens to be the typical space between the lites in a narrow triple pane.

In this configuration it is quite possible to get an R-10 on the window. But, this is a center-of-glass measurement and is not necessarily indicative of window performance as a whole. Still, this configuration is very energy efficient and works really well...the downside is that this version can be expensive.

The wider triple pane version would generally have an airspace of about 7/16" between each lite. Again, the advantage is in the LowE2 coating on two separate lites. In this case, argon gas would be the most cost effective fill - rather than krypton. Argon is cheap and plentiful and at the 7/16" spacing is almost as good as krypton in performance numbers - not quite as good - but the slight insulating advantage of krypton in this configuration doesn't offset the additional cost of krypton.

The biggest disadvantage of the wider triple pane is the physical size of the IGU - or more precisely the width of the glass package.

While manufacturers who use this version build their sash to accommodate the IGU width, not all companies can do so, so not all companies offer a triple pane package because of both the perception and the actuality of the unit width.

The wider version of the triple pane (argon fill) may be a bit lower than the narrower version (krypton fill) in center-of-glass R-value at about 8.5 or so. But, as a generalization, the wider version may outperform the narrower version if both use argon or air infill between the lites.

And as a comparison, a dual pane with LowE2 and argon will get to about an R-6 center-of-glass.

One interesting downside to the increased energy efficiency of the triple pane is the likelihood of increased EXTERIOR window condensation on cool mornings.

Often, people who replace energy deficient single pane (or dual pane) with more efficient LowE coated windows become concerned that their windows are having "problems" with exterior condensation on cool mornings.

This is actually quite normal and indicates that the windows are performing exactly as they are supposed to do. Well, by increasing the energy-blocking performance of the window it is quite possible to increase the likelihood of exterior condensation. Not a problem in the sense of a window flaw  but some people do find it objectionable.

Either way, a little sunlight "fixes" that problem pretty quickly. Although in certain areas of the country it is actually possible to have frost or ice formation on the exterior of super-efficient windows in the winter time  which beats having it on the interior I would venture to suggest!

Ultimately, the best window in the world wonÂt do you a bit of good if the installation is flawedÂso once you decide on a particular window; make sure that the installers know their business!

Thank you so much for your time and all the information...I just want to be well informed before making this decision and not feel like I'm making it in the dark.

I just had a demo from penguin windows Triple pane $15,000 Life time warranty transferable,1 Bay, 2 small bath& kit,4-reg/large

Oberon has great info Snow and also keep in mind that the extra layers of Low-E2 on the multiple glass surfaces lower the visible light transmission so in essence the money you could potentially save with increased efficiency could be lost with darker rooms and the need for artificial lighting.

Pella "triple pane" window is not a sealed window, it's just there to hold a screen. You want a REAL R9 triple pane window.

I'm having a hard time getting these guys to give me even a price on triples.

Solution:
Energy Star,Northern Zone windows will be required to have a U rating of .22 by Jan 1, 2010.

Wait till 2010.

Who has the best deal on these windows? cameron109@yahoo.com

We also made the fatal decision to purchase Pella Windows. We would like to give you an update. We are spending the 3rd summer homeless because of our fateful decision to purchase Pella Windows. Pella has sent to our home teams of men. The last team of 4 Pella employees was in our home in January 2011. At that time, that team told us that Pella would be glad to manufacture a 3rd set of 49 windows and have them installed by the end of February 2011. We agreed to this process. It is July 7, 2011 and we have not seen anything from Pella since January 2011.

We installed the first set of 49 Pella Architect Series double hung douglas fir windows in October 2009, the second set in February 2010 and are awaiting the third set. As you can see from our first post, we paid in full for our window order in 2009 and have been sorry for that decision ever since!

We posted a Youtube video at http://www.youtube.com/watch?v=T8vYK2cy-9Y about our home and created a website at pelladecideforyourself.com. We hear from families on a nearly daily basis that are in our similar boat. Pella has proven, unfortunately, to hundreds of families that we know of, to be a company that does not stand behind their product. As a Christian family, we are extremely disappointed with Pella because they are located in a well known Christian Community. We have had to, after 3 summers, contact an attorney. We do not believe in law suits, but we are homeless, for no other reason than the fact that our brand new Pella Architect Series double hung douglas fir windows leak water/air/snow.

Please make your window purchase from any other company than Pella. They are involved in a class action law suit involving their Pro Line Windows. It is obvious that they just cannot stand behind their product, as they have been cheating families for years.

You will find that Pella triple pane windows are cheaper than most other triple glazed windows. However, you may also notice that the energy efficiency of other triple panes tend to be better than the Pella product. This is because, the Pella triple pane window is not a sealed window. The interior glass panel is removable. This makes the Pella triple pane window more like a standard double pane window with a snap-on panel of glass on the inside. Obviously with this set up, there is only one space that can hold the argon gas, as there is really only one sealed compartment. It seems though the Pella design actually works better for noise reduction than the standard triple pane window design.

Customers who have purchased the Pella triple pane designer series have generally expressed satisfaction. Some however have been disappointed, thinking that the energy efficiency should have been better for triple pane windows. But once you understand upfront what you are getting, and you are comfortable with that, you will probably be satisfied with the quality as many other customers are.

Just to expand, Pella has fully sealed triples in its newish premium vinyl line (350).

If going with Designer, I'd probably look at getting a second low-E coating (on the hinged glass panel). This would close the thermal gap with sealed triples to a decent extent.

I would not put Pella vinyl in my dog house and anything else Pella only under major duress!!

Agree, pella does not offer a high quality vinyl. their new 350 series isnt bad but not up there with the higher end vinyl offrings.
Those brands would be Sunrise, Okna - HiMark - Soft Lite, and Gorell.,

Having actually researched this I can say that the best windows are quadruple glazed windows. However Triple glazed is excellent too. Just ensure that you buy from a manufacturer that uses a gas fill. I got some from Klearwall and they used Argon gas which has great insulation properties. To ensure that your triple glazed windows are good quality I would suggest you look out for a Passive House certified product

Hey " Greenfinger1" , dont think you can come to this board and start spamming your company. You make it sound like a scam . No one ever joins a board just to say how happy they are. Get a life and erase your post.

Read up on Passivhaus standards and what is required to make a home truly efficient and comfortable.

cwaguespac, the post is a year and a half old............

I just had my triple pane install and boy are they dark. I wasn't expecting this. Anyone else had this problem?

Triple pane really isnt dark unless you choose a window with a low shgc.

ive never had one customer complain.

however, i know Pella use lowE 366 and thats very dark and not meant for the east coast. I also would never recommend Pella..

Bonnie,

who made the window? and do you know what LowE coating was used?

Shame on your salesmen for not educating you about losing visible light..if your using triple insul glass in your climate you dont need as many coatings if LowE because alot of those climates want the solar heat gain..