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Performance of Alpen Windows

rockies63 | Posted in General Questions on

In another question on the site someone asked about Alpen windows and in looking at the Alpen site they mention using thin glass instead of a suspended film for energy efficiency.

Thin Glass WILL Change High Performance Windows

There’s also this video from AE Building Systems discussing the different types of Alpen glass.

Has anyone used these units and if so, how did they perform (apparently they can hit an R(.5)? Were there any issues with handling or installing them?

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  1. matthew25 | | #1

    Bumping this thread as I am also curious about Alpen windows. Their Zenith R-10 series and new Tyrol R-11 series seem too good to be true. I’m also looking at Zola which makes an “arctic” R-10 window.

    As far as I have found, these two companies are the only ones making R-10 windows for the residential market. If someone else knows of other options, please share!

    Also looking for door manufacturers. ProVia makes an R-10 door (no lite) but haven’t found anyone else so far.

    1. andyfrog | | #22

      Litezone makes some ridiculously high R-value IGUs, but they use a less common approach with many layers of PET films between two glass lites. They seem interesting, though I wish it was easier to find customer testimonials and I can't find anyone using their IGUs in fiberglass windows.

  2. Jemari | | #2

    Also curious about any experiences installing, using, the Alpen Zenith line (fiberglass), and working with Alpen as a company.

  3. nynick | | #3

    Me too. i'm seriously looking at the Tyrol series and have several quotes.

    1. matthew25 | | #8

      nynick can you share any cost per sq. ft. values for some fixed vs operable Tyrol series windows? And what model line specifically? It would help me with budgeting for my future build. My email is matthewwilliamson55 [at] gmail if an email is easier.

      1. Tim_O | | #9

        It's pretty variable, but I got quotes on the TR-6 line to get a rough idea. Larger the window, the less per sqft. A 4x6ft fixed window was around $45/sqft and a similar sized tilt/turn was $70ish per sqft. I'd be curious to know how the TR-11 or TR-9 series compares.

        1. nynick | | #12

          These prices don't match mine whatsoever.

          1. Tim_O | | #13

            That's the very size dependent portion it seems. I had some smaller windows on my estimate that come in similar to your pricing. I didn't include shipping in my numbers here, that was another $2300 or so (Alpen to Detroit) for 15 windows and a patio door.

      2. nynick | | #11

        Yes, although I'm not really sure that's the preferred way of making comparisons. Generally speaking, Alpen and SHUCO were about 29% more expensive than Marvin double glazed double hung. You pay for quality windows.

        Here are some examples of Alpen prices:

        White, triple glazed, muntins included.

        Tyrol Series 6 Fixed 24x27-$535
        Tyrol Series 6 operable hopper 24x27-$728

        Tyrol Series 6 Fixed 28x53-$1029
        Tyrol Series 6 T&T 28x53-$1342

        Tyrol Series 6 Fixed Picture Window 69x53-$1055

        When making cost comparisons, make sure you consider delivery and sales tax. Since I'm in CT, there's no sales tax but there are delivery charges for Alpen. The Marvins were quoted from the local lumber yard, so there IS sales tax but no delivery. Shuco had a huge delivery charge from Poland.

        Hope this helps.

  4. pjpfeiff | | #4

    Not sure how helpful I can be, but I bought exactly one of their windows to replace a large picture window that is right behind our couch. It's a U-factor 0.14, so about R7. I took some measurements on a cold night and that, as I recall, were consistent with the rated U-factors (center/edge/frame). I hired some people to install it who I warned about the thin middle pane, but I can't really say whether they handled it with any extra care or not.

    I also got a quote from who can go up to ridiculous R-values. They were pretty responsive, but the shipping was too much for my small order.

    1. Jemari | | #5


  5. rockies63 | | #6

    Pjpfeiff: How does it feel sitting on the couch with your back to the window? Do you notice a big improvement in comfort from not having cold radiating into the room right behind you?

    I think with Litezone they only make the glass unit and supply it to the window manufacturers.

    Three of them are in Canada - Aluprof, Fenstur, and Duxton.

    One is in the Us - Vetrina.

    1. pjpfeiff | | #7

      Yeah, I think I can still tell that I'm in front of a window, but it's much better than before. One confounding factor, though, is that the installers discovered a big gap in insulation all around the window opening and filled it in. So part of the improvement is due to that.

      About Litezone, you can buy directly from them, but yes, it will be just the glass unit. They have some instructions for a "frameless installation" on the site, so that was what I was considering doing.

  6. scott_tenney | | #10

    We used Alpen windows for our home in SLC. The windows and doors have been great but there were some issues with a door handle and lock and the customer service was really poor - very slow responses.

  7. rkymtnoffgrd | | #14

    I priced and purchased Alpen 525 (Zr-5) Series (Fiberglass) for my Passive Solar build. This is the zenith line not the Tyrol. These are a "5M Thin Glass Triple", 1/8" Glass Thickness, Argon filled, with breather tubes, specified to different SHGC for different locations based on required solar gain.
    1)Front windows (passive solar) are U-Factor .19 and NFRC SHGC .48
    2)Side windows (no passive solar gain) are U-Factor .19 NFRC SHGC .31
    I purchased last year, in the height of the supply chain/demand and crazy high prices... And Alpen was not that much more expensive that Clearview and Anderson Energy Star options but the performance was significantly higher. For instance the "high solar" big windows (36"x72") you see in the front pictures were $812 from Clearview and $824 from Alpen. But U was .26 vs Alpen at .19.
    I installed the windows myself, they come with a breather tube that must be crimped shortly after delivery . These fiberglass windows are heavy and seemed very robust during installation. Crimping was straight forward, and the fact the windows were manufactured at 5K feet and then delivered and crimped at 10k helped ensure the gas stays intact. Alpen also distributes the "Thermalbuck" I purchased and used for installation for my exterior insulation...

  8. rockies63 | | #15

    You know, $824 for a 3 foot by 6 foot ultra high performance window is very good, in my opinion. Considering that your windows are going to be in that wall for the next 25 years I don't know why people freak out over high window prices. The critical thing is the installation - air and water sealing it and then the flashing and window trim.

    How did you find the Thermalbuck to work with?

    1. nynick | | #18

      Well, my window/door package is coming in around $77K, 29% higher than standard Marvins.
      I get it. They're good windows.
      What's your freak out price?

      1. Expert Member
        Michael Maines | | #23

        Nynick, if your total window/door package is $77K and a 3'x6' window is $824, that means you have the equivalent of 93 windows that size?! I think I would have freaked out about the quantity of glazing and/or the size of the house long before worrying about the cost.

        1. nynick | | #26

          Yes, Mike, I hear you. Unfortunately my home is a renovation/restoration of a small 1850's home, being sympathetic to the architecture of the day. In addition I am adding a conditioned "sunroom" which adds about 40 feet of continuous windows. Plus, theres a new detached 2 story garage going up, so I'm adding 17 more windows to the package. All in all, I think it's around 59+/- windows and doors.

    2. rkymtnoffgrd | | #20

      I knew about "Thermalbuck" for a while, I had intended on making my own using Zip R12, but when I found out that Alpen is the colorado distributor for Thermalbuck, I just had them put it on the order. I found that the Alpen ZR-5 series was in line pricewise with all the major competitor Energy-Star options, but the "listed" performance was much better. This is no doubt that Alpen was only one offering a T pane Argon filled window in that price range. It should be noted that "Energystar" rated windows are a long way from ultra high performance (like the some of the Tyrol line) but offers a much more reasonable payback and comfort in my opinion. They also provided my Provia Fiberglass Doors, which also seemed to be a really good blend of performance, durability, and price in my opinion. The entire house, with the doors was 22.8K delivered (With thermalbuck included!). After my search, I thought that was a great price for the 24 Windows with u-.19 and 3 doors...

  9. mhenson | | #16

    I purchased the ZR-6 fiberglass bronze for the new house we are building. We are in Colorado at 8,500ft Pete Beaupre at Alpen was my rep. He was very helpful and worked through all my questions, he tried really hard to get me to drive up to the factory and look at everything, but I never had time. The Windows were delivered after about 8 weeks. This was so late last year that we postponed the building until this spring. I have 28 windows ranging from 24"x17" all the way up to the picture windows that are 96"x72". We crimped them all and they are sitting in the barn waiting for spring. I hope they live up to their ratings. One thing he told me that was interesting is that the triple paned windows won't really save me much if any on heat retention, it is mostly about comfort and not getting cold drafts when you are close to the windows. Most of the windows are side sliders and 4-5 feet wide, all of them ran a little over $35K. U factor rating is .14 on all the small/medium windows and .16 on the large ones.

  10. entropic | | #17

    Thanks to all of you who have purchased Alpen windows for sharing. Another potential benefit of “better” windows (triple pane or not) might be air tightness. Does anyone happen to have air tightness metrics for Alpen windows?

    1. xbcornwellco | | #27

      Since you asked and no one replied yet. Air Infiltration operable @l.57 psf (@75 Pa), 0.02 cfm/ft 2 (0.1L/s/m2 ).. And fixed, <0.01 cfm/ft2 (<0.05 L/s/m 2 ). I know Alpen is obsessive about having no air leakage with their windows.



      I know Alpen puts their AT ratings on their energy label window sticker, but darn if I don't wish ALL window and door manf's were REQUIRED to do the same. No volunteer metric, but required. Seems like such an important metric these days with higher quality builds.

  11. jimkas | | #19

    We used ZR6 on a project in 2020/ 2021. This was an addition to and renovation of a 1985 home in the mountains SE of Denver. CZ7, 8200' with significant exposure S,E,W. These were film.

    The replaced windows in the existing structure were original Pella units. These windows has started to fail.

    It is hard to quantify energy savings as the project also included significant additional insulation, air sealing and changing the heating from forced air to radiant floors with high efficiency boilers vs 80% furnaces. The addition and related spaces added approx 1.5X the original square footage and it all coincided with the massive price inflation to fuel.

    However the comfort factor is enormous. Compared to the original windows you can sit near and in front of the large Alpens on the coldest days and nights and remain comfortable. The new spaces have large glass openings on some sides and are uniformly comfortable regardless of the outside temperature.

    The only hitch has been customer service. We had some issues as delivered and unfortunately are still working through getting them resolved. IT seems we have a good team in place now, but it took 12 months of a barrage of contacts to get them to respond, then the fixes were only partial and very halting. We are hoping this can be chalked up to the pandemic rush and attendant labor shortage and hope it is getting better.

    The products are fabulous in terms of fit, finish and function but did have a few issues. However getting the issues resolved has been a struggle. Thankfully they are mostly cosmetic.

  12. rockies63 | | #21

    I guess my freak out price would be anything over $150 per square foot, so that 3' x 6' window for $824 works out to about $46 per sq' (at 150 per sq' it would be $2700). Of course, that depends on the style of the window.

    One thing I've read is that the larger the unit the cheaper it is because most of the added cost is in the frame so a 72" x 48" window is cheaper than two 36" x 48" windows. Also, many people put in too many operable windows - one egress window per room is usually enough with maybe two in a large room for cross ventilation.

    Here's a couple of great videos on Litezone glass if you're interested.
    Part 1
    Part 2

    And this one from Matt Risinger.

  13. xbcornwellco | | #24

    "The pricing for the Alpen windows was not more expensive than even conventional windows despite having twice the performance, a better warranty, and similar lead times. We didn’t pay any more to get Passive-House grade windows".

    I personally LOVE Alpen, and you really don't know a high performance window until you see Alpen, IMO. Even the balloons, and NAMI certified gas retention system for high altitudes is one of the many cool and super engineered geeky things with Alpen. They've been around since the 80s, have their own indoor testing chamber, PH DUAL certifications, etc. Super, super innovative and kind company.

  14. PAUL KUENN | | #25

    I'm just about to install 6 Tyrol at .012 UF at 72x53" and have been impressed so far. WI Rep is pretty responsive when needed so no issues. 4 smaller at 36x53". One all glass door at .018 UF. One double French style door. 500+ pounds.

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