One of the most exciting potential projects in the world of construction is the concept of water-filled buildings, which could become a complete and total game changer for insulation, heating and cooling our homes in a more sustainable way.

These water houses, pioneered by startups such as Water Filled Glass (WFG) would run water through the window itself and allow for buildings to continue to be heavily glazed without the need for more active cooling and heating systems to run at all times.

One of the most interesting and important elements of the water home concept, however, is the role a mains water filter will play in ensuring that safe, clear water passes through the window and around the home.

Water filtration is key, and one of the biggest aspects of it will be how the same ultraviolet rays that the water glass protects you from also help to filter and purify the water passing through it.

To understand this, we need to explore how UV filtration works, how windows are typically made and how the water home could be a win-win situation.

How Does Water-Filled Glass Work?

To understand how water-filled glass works, it is important to know how windows are typically constructed.

Most windows are made of at least two panes of glass, spaced apart, with the remaining space filled with a gas such as argon or krypton or dehydrated air that slows down the rate that heat travels through it.

This means that heat escapes or enters at a slower rate than it would for a single pane of glass, but it is still far from an ideal solution, and following several temperature records that have made indoor working nearly impossible during the day in some locations, a lot of solutions have been suggested.

Currently, the most popular solution to this is blinds and window tints that absorb or reflect light away from the building itself. However, water-filled glass could potentially be a far more effective solution with a range of hidden benefits.

How it works is that instead of having the space between the two panes of glass be filled with dehydrated air, it is filled completely with a thin layer of water, which is constantly pumped through the windows via a series of sealed pipes.

This concept in principle combines UV filtration, heat pump technology and the general heat-absorbing properties of water, which WFG themselves claim can be attained using current types of glass and off-the-shelf components.

Essentially, water passes through the window, absorbing UV rays and heat along the way before travelling inside the building itself, where it can be connected to a conventional heat exchanger system to store the heat to reuse another time or to a series of pipes to ensure the water is at an optimum temperature.

During colder weather, the process can be reversed, with warm water passing through the system and creating an insulating layer that stops heat from escaping the building.

The system has been tested and in very cool climates, the typical double-glazing system has an additional glass layer to stop the water from freezing.

According to WFG, the water glass can lower energy costs by up to 75 per cent compared to current conventional windows, and because the system can be made from currently available parts there are no additional embodied carbon costs.

However, the most important part of the system is one that is not immediately visible.

The Unseen Filter

Given that the water is passing through a window, it is essential that the water passing through is adequately filtrated, for reasons that go beyond simple aesthetics.

When the system is working at its most optimum level, it is essentially impossible to notice that there is water passing through the glass. The water layer is relatively thin, is travelling up the pane relatively slowly and the part of sunlight that water would absorb would be the part that human eyes cannot see.

However, this all relies on the water being pristine, pure and free of impurities, which is where a wide range of water filtration systems come into play.

Whilst this water is unlikely to be part of the drinking supply, the types of combination filters using charcoal, UV filters, mechanical filters, ion exchange and reverse osmosis are exceptionally important for a range of other reasons.

The first is simple aesthetics. Windows are difficult to clean at the best of times but if the origin point of the dirt, debris or mark is on the inside of the pane itself, it could be difficult if not impossible to rectify without draining and taking apart the system.

Depending on where the window is, this could be potentially extremely difficult if not outright impossible in some cases, which means that ensuring the water is free of impurities in the first place becomes essential.

Another part of it is functionality. Whilst the pipes slowly push water up the glass pane at low pressure, the relatively thin nature of the pipes means that there is still a risk of small pieces of sediment clogging up and ruining the window’s thermal effects.

Whilst this is unlikely given that the system has a monitoring system that is tested annually, it is not something that is worth taking a risk on.

Finally, there is a rather unique quality of water that only affects particularly cold climates.

Water is said to freeze at around zero degrees Celsius (32 degrees Fahrenheit or 273.15 Kelvin).

However, this is not necessarily always the case, as water needs a solid to freeze around, with an experiment finding that water could be as cold as -48 degrees Celsius in particularly unusual circumstances.

The greater the impurities in the water, the closer to zero its freezing point is and the greater risk of it causing damage to the inner workings of the water-filled glass.

In most situations, this is unlikely to be the case as the standard design for a WFG system is to heat the water beforehand, but filtered water helps to make this system work better and last longer.