Smart Glass, also called electrochromic glass, dynamic glass or switchable windows, is being touted as a technology that will help reduce the effects of climate change if homeowners embrace its use instead of their old glass windows.
Smart glass allows the homeowner to tint or untint window glass as needed at the touch of a button. The technology uses electrochromism, which is the capacity for some materials to change color or opacity when a low voltage current is applied.
No more fiddling with blinds or curtains to open your home to the outside or alternatively, to block it out. The convenience is certainly compelling, but in the home setting, is it really more environmentally-friendly than traditional ecological solutions such as energy-efficient glass block? Is it all hype? Does the cost-benefit analysis make it worth it?
Let’s take a look at the major pros and cons of smart glass windows vs glass block windows to see how they compare.
Smart Glass – Pros
Smart Glass Windows offer home energy savings
Currently Smart Glass is most used in commercial buildings with large windows or glass walls that make controlling the glare and heat from the sun very difficult. In this setting, smart glass has a big impact, using the sun’s energy in the winter to contribute to heating and deflecting the sun in the summer, minimizing the need for air-conditioning. For example, the Empire State Building was outfitted with smart glass in 2012, and within a year had saved $2.4 million in energy bills.
The same principle applies in the home setting, and since building operations generate about 27% of global CO2 emissions, it makes sense to ensure that heating, cooling and lighting are as efficient as possible.
Smart Glass Windows offers convenience of adjustable light transmittance
There are, of course, other ways to achieve solar control in the home. Blinds, curtains, or awnings will all allow some degree of control over how much light enters your home. However, drapes might not be practical in modern commercial buildings or home design that incorporates a lot of glass, and the convenience of smart glass in these settings is undeniable.
Even in more traditional home design, the convenience of smart glass is compelling. The homeowner can easily tint or untint windows with the press of a button or even a voice command and has minute control over exactly how much light is transmitted. Or the homeowner can install sensing devices that will automatically adjust the lighting. In the daytime, the glass can be adjusted to allow enough light for the occupant to see and be comfortable while still protecting privacy. At night the glass can be turned to black out which blocks 99% of light.
Smart Glass Windows block UV rays
Smart glass blocks between 40-98% of UVB and UVA rays depending on whether it is turned on or off. It also blocks about 40% of infrared light, which is the frequency that produces heat.
UV rays can fade furniture, rugs and artwork. They can even damage hardwood floors. Installing smart glass will help protect the interior of your home from these rays.
Smart Glass Windows have great style and versatility
Glass connects the inside of the building to the environment and has been a growing trend in North America for the last hundred years. Smart glass solves the privacy issues of this type of design and increases the element of elegance that large panes of glass induce. Smart glass allows architects the creativity to experiment with design.
Smart Glass Windows: Cons
Smart Glass Windows usually require electricity to work
Granted, it doesn’t require much electricity to work. And some technologies don’t require any electricity at all — they work much in the same way as sunglasses that automatically adjust to the level of light do — but this technology doesn’t allow for precise adjustment either.
Of the technologies that do require electricity, different ones require slightly different amounts of it, but they are all low — 3-7 watts per square meter. For example, one hundred and fifty square meters of electrochromic glass at 7 watts per square meter, uses less electricity than a 60 watt incandescent light bulb.
Of course, in power outages, you will be left exposed unless you have a generator or back-up drapes! Smart glass might not be a good fit for the off-grid crowd.
Smart Glass Windows have a high initial cost
The cost will depend on the specific technology used to produce the smart glass, as well as the manufacturer. The cost is about 50% more than a dumb window. In 2022, this translates to about $50 -$100 per square foot. Does it work out in the cost-benefit analysis? Smart glass will last about 20-30 years and with today’s home operating costs will save you about 20% on your energy costs. You do the math for your situation.
As smart glass becomes more popular, the price is likely to come down. In the meantime, there are cheaper versions: self-adhesive switchable glass.
Glass Block Windows– Pros
Glass Block Windows are eco-friendly
Glass block are made from sand and limestone, last at least 50 years and are completely recyclable, all of which reduces construction waste, and helps the environment.
Glass blocks also contribute to lowering energy costs in the home with some glass block meeting federal Energy Star guidelines. For example, Seves ‘Energy Saving’ Glass Block, has a U-Value of .19, which indicates a great insulating capacity. As well, solar reflective glass reflects heat away from the interior during summer and prevents heat from escaping during winter. It also protects against harmful UV sun radiation.
Glass Block Windows provide light transmittance
Glass block allows natural light into your home while still protecting privacy. Glass block comes in a wide range of colors and patterns so you will be able to choose the right amount of light transmission for your light and privacy needs.
Glass Block Windows are secure
Some Glass block is built with security in mind. For example, our THICKSET® 60 & 90 product line, as well as our VISTABRIK® and Vetropieno™, are much stronger than conventional glass block due to the thickness of the glass. These products can also withstand severe storms such as hurricanes and tornadoes.
Privacy also can contribute to security, and as mentioned above, you can choose various patterns and colors according to the amount of privacy you require.
Glass Block Windows are highly functional
Glass block can provide a more peaceful atmosphere as well as peace of mind since they are resistant to:
Glass Block Windows offer a unique style and great versatility
Glass block come in a variety of colors and patterns, giving designers and architects the ability to use their inherent qualities of light, color and texture to create unique spaces. The functional qualities of glass, such as its strength, light-diffusing qualities and durability make glass block amenable to a wide range of uses from extremely functional such as basement windows to the extremely beautiful, such as glass block walls.
Glass Block Windows – Cons
Glass Block Windows are heavy
While their weight also contributes to their security and functionality, it also means that you must take this into account when you are designing your space. Extra support may be needed. Despite their weight, glass block should never be used as a substitute for load bearing walls.
Glass Block Windows do not offer traditional ventilation
Glass block are air tight, but what is a benefit in some situations can be a downside in others. Most glass block absorb heat but do not allow for ventilation, potentially creating a very warm and airless space. When designing a room that uses glass block, especially in humid areas such as bathrooms, be sure to include a glass block window vent to allow for fresh air and proper ventilation.
The Verdict: Smart Glass Windows vs Glass Block Windows
It really depends on what you are using them for. Each has their benefits in very specific circumstances. Smart glass is the obvious choice if your house design dramatically employs great expanses of glass, whereas glass block offers a charming aesthetic that is affordable and provides exceptional security and functionality. Both are environmentally-friendly options.