When I read a headline such as A Piece of Glass Thinner Than a Credit Card Could Solve America’s $25 Billion Energy Problem, there is a pretty good chance I’m going to investigate and a lesser chance that I will write about it – but here, we go.
The Wall Street Journal article states that double-pane windows have hardly changed in their 100-year history, although I find it hard to believe they existed a hundred years ago. More likely, they are speaking of the old double-hung, rattling windows with counterweights with crappy storms on the outside. Want to see what those look like? Here is a fine video for that. While I watch it, I can feel the cold pouring through the sashes and cavities surrounding the unit.
Building Shell Heat Loss
The Journal says windows lose 10-20X more heat per square foot than typical walls. Per my specification, a standard window has an R-value of roughly 3. Windows rated to ENERGY STAR specifications have an R-value of about 4.5 for “northern” climates. ENERGY STAR wall specifications call for composite insulation levels to be roughly R-25, so a ratio of 10-20X is unlikely. Nevertheless, window insulating values are critical.
The headline $25 billion in savings is based on $200-$400 in annual wasted energy per home due to “drafts, air leaks around openings, and outdated heating and cooling systems,” as gun decked by the Department of Energy and referenced in the Journal’s article. Statista reports there are 85 million single-family homes in the United States. Well, golly! If I take the midpoint of $300 per household and multiply by 85 million households, I get $25 billion in annual savings potential. However, the demons in the details reveal that the average savings potential includes loss reductions from ALL air leaks, not just window leaks, AND HVAC equipment replacements.
The Journal goes on to evangelize these windows. These windows “could enable the construction of new homes that are so well-insulated that even when the power goes out in a winter storm, they stay warm for days,” and “these windows can meet the most stringent hurricane-related building codes in the country while being significantly lighter than conventional stormproof windows.”
The Secret Window Ingredient
The secret ingredient of these uber-insulating windows is gorilla glass, like glass on smartphones. Traditional sheet glass is manufactured by floating molten glass on top of molten tin. This process is inexpensive but results in microscopic imperfections that make it brittle. Gorilla glass, demanded by Steve Jobs for the iPhone, “cascades” a different chemistry “in a waterfall as thin as a half millimeter” to produce glass that is nearly flawless and, therefore, not as brittle.
How tough is it? Imagine a sheet of glass the size of a queen bed with a thickness of less than a credit card. It blows my mind to think of even picking that up without breaking it.
These svelte sheets of glass are sandwiched between traditional clunky glass, and each gap between sheets is filled with inert gas (e.g., argon) to form a super-insulated window. This manufacturing process allows the insulating value of the window unit to “skyrocket,” per Lawrence Berkeley National Laboratory swami, Stephen Selkowitz.
Company Behind the Technology
Here is the fascinating part: Alpen, a company out of Colorado, is the designer and manufacturer of these windows. Hmm, I once had a presenter on a panel of mine for new technologies at AESP’s SummerCon 2023 in Indianapolis. The man’s name? Brad Begin, CEO of Alpen High Performance Products. On January 8, 2024, Glass Magazine reported that Andrew Zech took the helm as CEO, replacing Mr. Begin. Zech is noted in The Wall Street Journal piece.
Assessing the Technology
I was headed in the direction of my research here anyway because I had already considered these windows for a new home I am planning to build some year. The technology seems legit. However, a holistic design is necessary, as usual. Huge windows using this technology allow solar energy to pass into the home in winter, but this is a negative in summertime without appropriate glazing orientation and shading devices. I recommend any giant glass walls facing north or south with appropriate shading to avoid unwanted solar gain at the wrong time (summer).
The glazing technology has another benefit: storm and hurricane resilience at 40% less material and weight.
There is a good chance you’re thinking, “OK, Jeff, how does the cost of these windows compare to standard “energy-efficient” window costs (presumably, ENERGY STAR equivalent)?” The Journal reports a 20% cost premium. My conversations with Mr. Begin, the former CEO of Alpen, did not deter me on price, although I am an energy freak, so consult with your hardcore ROI partner as necessary. Only tell them I sentcha if they approve.
Implications for Decarbonizing Buildings
The mantra of efficiency first, ahead of adding renewables, applies to building envelopes and electrification of HVAC, specifically, space heating. To avoid breaking the grid with massive peak loading in cold winter mornings, heating loads must be minimized. The way to do that is with envelope improvements, including breakthroughs in the most “heat-leaking” area: the mundane window.
Storm Bonus
Speaking of storm and hurricane resilience, millions of Americans are experiencing skyrocketing home insurance costs or dropped coverage altogether. Why? Infamous wildfires, like the Eaton and Palisades fires in California last January? No. Hurricane Helene that devastated parts of Florida, Georgia, and North Carolina last year? No. Tornadoes? No. Floods? No.
What the H is it, Jeff? The lowly ice ball – hail produced by so-called “convective storms.” (I would say every storm is “convective” in the sense that warm air rises rapidly and is displaced by cold sinking air, producing a powerful atmospheric engine I described eons ago.)
Figure 1 from Phys.org provides a good idea of the complex three-dimensional churn (convection) in a tornadic, hail-producing storm system. Figure 2 from the University of North Texas illustrates hail production. The freezing point is roughly 15,000 to 20,000 feet.
Ice forms and falls out of the updraft as a small hail stone. It grows as it is again lifted by the updraft to add more ice at higher altitudes. The loops continue until the stone is too heavy for the updraft and falls to earth. It doesn’t take much, in my opinion, to produce a golf ball-size hailstone. An updraft speed of only 64 mph will do it. Golfball and walnut-size hail can destroy a roof with flimsy asphalt shingles and damage cars and windows.
Figure 1 Anatomy of A Tornado and Hail-Producing Storm
Figure 2 Hail Production
