Brent Hull Discusses Pilkington Spacia Glass
rockies63
| Posted in General Questions on
Has anyone used Pilkington Spacia Glass? Apparently it has a very high insulating factor.
Brent Hull’s Passion for Craft Podcast: Minute 1:30)
https://www.youtube.com/watch?v=sWSiRrN57O0&t=20s
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
rockies63,
You should note that the limited info available at the link provided says that the Spacia offers up to four times better thermal performance than single pane. That translates to up to R4 in my mind. R-10 is offered by Alpen with capability of going higher with expensive Krypton fill. The product is quite specifically aimed at upgrading windows that may not have room for standard IGUs or for historical buildings, special architectural covenants in place.
There are no magic bullets for windows just yet. There is progress on active coatings that can alter a windows infrared profile to allow solar gain in winter and block solar gain in summer. If it makes it out of the lab, look for first applications on commercial buildings.
Haven't used that one, but have handled similar the Vitro product VacuMax. These are Vacuum Insulated glazing, per the Vitro literature it achieves R14 in almost the same thickness as single pane glass. Two things I noticed: the little "pillars" aren't as noticeable as I thought they would be from any real distance; and the edge of glass may be slightly bigger than more traditional frames may accommodate.
https://www.vitroglazings.com/products/special-applications/vacumax-vacuum-insulating-glass/
I would call that a magic bullet based on the R-values ;)
RE #2
Aaron,
If you have handled them, does that mean installed and assessed performance? The literature says R-14 but the fine print reads,
"Above data is for reference only. Calculation method not approved yet by National Fenestration Rating Council (NFRC) for VIG units."
Do you have outside verification of the value stated? It would indeed be a magic bullet if true. The fact that it seems to be a niche product like Spacia tingles my spidey sense. It could be the little dots on an ~3/4" grid make the aesthetic a hard sell. Or it could be that they are simply too pricey for general use.
They may have actually achieved R-14 if the gap relative to Spacia is what it appears. Spacia says its units are just over 6mm thick with a 0.2mm gap. The VIG units suggest the gap is possibly 2mm as the final unit size is noted to be "just 8.3mm". That rather sizable jump in the gap could be the magic bullet ingredient. At 0,.2mm I suspect that radiant transfer is at play between the panes to a much greater degree.
I am most curious to see a photo of a VIG unit taken by ordinary folks. The spacer dots or pillars must show at certain light angles. As former professional advertising photographer I am aware of how much one can enhance or suppress the visual presence of such a feature.
Brent is a killer craftsman, but his window knowledge is way off.
#1: https://www.gsa.gov/climate-action-and-sustainability/center-for-emerging-building-technologies/completed-assessments/building-envelope/quadpane-windows Quad ThinGlass 3 year ROI.
#2. Alpen makes WinSerts window inserts, enable 3-5x R value without replacing windows. Solves terrible aluminum frame problem on historic buildings. 10x cheaper.
#3. Vacuum insulation isn't the golden child everyone's making it out to be. Can't wait for it to all be imported from China only to fail (not). Look at the history of VIGs and tell me how is funding the multi-million dollar facilities now?
#4. Who upgrades from a R-1 to a R-2 window and uses that as a comparison to NOT upgrade windows. We are LEAPS beyond those #'s.
See the Empire State Building: 6,514 insulated glass units from the windows (rate of 150 per night), to add a low-e coated suspended film in the center of the units to create a triple pane, low-e coated window.
With Krypton gas fill, the new Alpen glass achieved center-of-glass U-factor reductions of:
North: -73% (from U-0.48 to new U-0.13)
South/East/West: -59% (from U-0.48 to new U-0.20) plus -52% solar gain reduction
Re-using over 95% of the existing glass.
"World’s Most Famous Office Building Exceeds Energy Efficiency Savings for 3rd Consecutive Year; Annual Savings 16% Above Target" Empire State Building with high-performance glass was estimated to cut the building’s energy costs by more than $400,000 per year.
#5. You can make Thin Triple IGUS that RETROFIT into double pane windows. But who has the manf capacity to do that... YET. The wave is coming.
The thing I wonder about is that I have read that if a sealed glass unit is manufactured at a low altitude (on the coast, for example) and then transported to a high altitude (up in the mountains) that the change in altitude can cause a pressure imbalance within the unit and the edge seal can fail (no matter if the units contain air, argon gas or krypton gas).
With the Pilkinton and VIG units there doesn't seem to be that problem - or is there?
rockies 63,
Given that the units are claiming a vacuum between the panes, altitude is largely moot. The little dots keeping the panes apart would actually be less stressed at higher altitudes. For the record, if you have not looked at Alpen windows, you should. The take account of the pressure issues by incorporating external bags to provide safe passage over the mountains. Once set in a house, you crimp the fine capillary tube and the pressures are stable. I have Alpens and favor them for their performance.
An important note if you are building at over 4,000 ft . Many manufacturers will not ship with argon or krypton above that level. The windows are just air. A pretty big hit on the U value.
How do the Alpen windows compare to those triple pane architectural windows that a lot of passive house architects (like Steve Baczek) get from Zola and Schuco?
There's also this LiteZone glass from Canada that only uses air between the panes (they just make the glass unit but can recommend window manufacturers that will install the unit in their window frames)
https://www.litezone.ca/
https://www.litezone.ca/air-filled.html
https://www.litezone.ca/pressure-equalized.html
https://www.youtube.com/@litezoneglassinc.2704
Here's an excellent video from Litezone explaining how their windows can achieve up to an R17 insulation value.
https://www.youtube.com/watch?v=fkt67aXtjjM&t=21s
Mentioned in the video (at minute 54:00) are several manufacturers that can install Litezone glass IGU's in their frames.
One is Fenstur Windows in Duncan, BC, Canada (Minute 39:40)
https://fensturwindows.com/
Another is Polar maxima in Quebec Canada (Minute 54)
https://polarmaxima.com/
Ferguson Corporation in Calgary, AB, Canada can make curtain walls with Litezone IGU's
https://ferguson.ca/
It seems Canada is pulling ahead when it comes to high efficiency windows and doors.
You can even install the units in the openings without using a window frame - just using wooden stops