Leah Berenson

Leah Berenson

January 17, 2025

Innovative Water-Filled Windows Use Sunlight to Regulate Building Temperature

Over the years, scientists and researchers have made some incredible discoveries, many of which we use daily. In 2023, a gentleman and his colleagues created something incredible. The team developed water-filled windows, a breakthrough in temperature regulation and energy efficiency. 

Creators of the Future

A cabin on the water. Greenery in the background.
Image Credit: WFG

Water-Filled Glass is a British based company that was founded in 2020 by Matyas Gutai,  Daniel Schinagl, and Abolfazl Ganji Kheybari. Incredibly, the team developed water-filled windows that work as “energy-saving heating and cooling” systems. 

Two Prototypes of the Water-Filled Window

A diagram of a first prototype of water filled glass.
Image Credit: WFG

Two prototypes were created, the Water House 1.0 and the Water House 2.0, each offering unique benefits. The first, 1.0, was built in Kecskemet, Hungary as a “small garden room or cabin.” Meanwhile, the 2.0 version is in Taichung, Taiwan at Feng Chia University and is a “pavilion.” The Water House 2.0, “turned the challenge of solar gain into an opportunity by absorbing the heat with the water layer and working as a solar panel.” 

Ample Sunlight and Breathability

A body of water from inside a building with large windows.
Image Credit: WFG

Each structure is designed with large open windows for ample access to sunlight, while the water-filled glass works to minimize energy use. Instead, it functions differently in Summer and Winter, for optimal energy efficiency. 

Reuse Energy

A diagram of heating.
Image Credit: WFG

In the summer, the water-filled glass absorbs heat and disperses it to “mechanical systems” throughout the home, such as hot water for the dishwasher or a shower. 

Minimizing Energy Consumption

A real life image of water-filled glass.
Image Credit: WFG

Meanwhile, the water-filled glass operates to “improve thermal comfort.” As a result, it minimizes energy consumption and keeps the area comfortable and cozy in the winter. Purportedly, the heat can be reused, contingent upon the kind of water-filled glass system that was installed. 

Several Options for a Water-Filled Window

A diagram of a water-filled glass power system.
Image Credit: WFG

Fortunately, there are several systems available so most people can find something that works, no matter what climate they live in and there are numerous “areas of applicability” according to the Water-Filled Glass website. However, the most common uses are for things like sunrooms and cabins. 

A “Retrofit” Water-Filled Window

A diagram of the water-filled glass.
Image Credit: WFG

Moreover, the team developed a “retrofit” system that can be applied to windows that are already in place, and 4 other systems. So, 5 systems in total, meeting various installation needs, regardless of their current systems.

Underground Installation

A diagram of how the water-filled window works.
Image Credit: WFG

For instance, some use underground pipes for cooling and heating, while others are “connected to a thermal storage.” The first is more appropriate for new buildings before the foundation is laid. However, another option provides comfort and energy savings without connecting to a mechanical system. Instead, thermal energy is generated primarily from the water-filled window. 

Patented Design

Image Credit: WFG

The patented design is not only incredible. It’s also a little far-fetched for most. However, the team used innovative and creative methods to develop something that will likely revolutionize the future of heating and cooling systems and one member of the team eagerly shared his take on the events.

Gutai notes that the idea is “outright mad.” 

“But we believe this is important because when you think about the energy of buildings and cutting carbon emissions, there’s still great potential and opportunity to think about glazing. Glass is responsible for a great part of heating and cooling energy consumption, and it’s a ubiquitous material, it’s on almost every building,” he explained, according to Dezeen

Commenting on the Water-Filled Window

Startup business concept. Strategic planning and business success. Businessman use tablet with startup icon on virtual screen for starting a new business.
Source: Shutterstock

And if you think about that potential, I think even crazy ideas are somewhat warranted,” he added. “Even if the idea sounds a bit mad off the bat, I think it’s important to think of alternatives to what we have. So we have crazy ideas, but we’re not crazy.”

They started as a simple startup from the UK but thanks to their innovative ideas and teamwork, the team changed how people utilize resources and helped create a healthier environment. The projected savings on energy bills is around 25% and they now serve customers worldwide. Water-filled windows offer a unique opportunity to reuse, reduce, and recycle. 

Geothermal Energy Efficiancy

Pipe system of floor heating mounted in residential building under construction
Source: Shutterstock

Another energy saving technique, as described by the Department of Energy is the use of a  geothermal heat pump, interestingly-used in tandem with some Water-filled window systems. This pump relies on temperatures from the “shallow earth” to heat in the winter and cool in the summer. Additionally, these systems also have several installation options to meet a range of needs, reaching a larger customer base. 

Solar Power

Workers building photovoltaic solar panel system on rooftop of house. Men technicians in helmets installing solar module with help of hex key outdoors. Renewable energy generation concept.
Source: Shutterstock

Meanwhile, larger scale efforts have been made in sustainability and energy efficiency. In 2014, NASA published a paper estimating that solar power use had increased by around 40% since 2009. A decade later, solar panels are highly recommended throughout the U.S. So much so, many states provide a tax credit, discount, or other incentive for going through with installation in your home. 

Wind Power

Green energy harvest with windmill and solar panels for eco-green sustainable concept
Source: Shutterstock

Alternatively, wind power has become a popular solution for sustainability. In fact, in that same article NASA noted: “Wind technologies generate far more energy than they consume.” Additionally, the lead author stated their research indicated “wind actually produces enough surplus electricity to support up to 72 hours of either battery or geologic storage.”

The Future of Sustainability

Wind turbines harnessing wind power during sunrise, set in an expansive agricultural landscape. Perfect for promoting clean energy and sustainability
Source: Shutterstock

He added: “This suggests that the industry could deploy enough storage to cope with three-day lulls in wind, common to many weather systems, and still provide net electricity to society.”

As technology advances, so too does the understanding that sustainable energy is essential for us to thrive as a species and a planet. Innovations like the water-filled window provide forward thinking and creative solutions to problems that most people tackle every day.