The 3 Main Systems of Curtain Walls: Face-Sealed, Water-Managed, and Pressure-Equalized

Curtain walls are the perfect solution to the often mutually exclusive phenomena – protecting the environment and saving money. This idea has especially gained popularity in recent years as companies all over the world are facing increasing pressure by the government, and their consumers, to become more eco-friendly. 

What Are Curtain Walls?

Curtain walls are commonly used to separate the interior from the exterior of high-rise buildings. They are unconventional from other forms of exterior surfaces because they are not essential to maintaining the structure of the whole building. Instead, they hold their own weight up along with protecting the site from climate patterns like strong winds and heavy rain.

Due to low labor and installation costs, reduced site operations, as well as high quality output, curtain walls are extremely cost-effective and environmentally friendly. In fact, largely as a result of the increased demand of environmentally-friendly alternatives, the compound annual growth rate (CAGR) of the global aluminium curtain wall market is expected to increase by 9.6% from 2020 to 2027. As of 2020, the market size lies at 34.6 billion USD, with a projected forecast to double this rate by 2027 at approximately 65.7 billion USD.

As such, it is imperative that manufacturers provide aluminum curtain walls as fast as possible to solidify customer loyalty before competitors. 

There are two types of curtain walls that may be selected, and differ based on how the components are put together.

1. Stick Curtain Wall

A stick curtain wall is best for low-rise buildings or buildings in smaller regions. This is because the components are put together on the building structure itself. The stick curtain wall system is also great for making adjustments to one’s blueprint in the moment, based on any issues that may arise along the way.

2. Unitized Curtain Wall

Unitized curtain walls are built within a factory and brought to the site pre-assembled. As such, there is no need for large cranes, or any other external forces other than a much smaller crane or even a short-term hoist. Moreover, since the curtain wall is built in a factory, on-site glazing is not necessary for making for quick and efficient installations.

Though unitized and stick curtain walls are the two primary types available, curtain walls may also be classified depending on the structure in place to stop water from seeping through joints and infiltrating the interior of the building. There are three main systems to select from – face-sealed, water-managed, and pressure-equalized.

1. Face-Sealed System (Traditional)

The construction of aluminium curtain walls using a face-sealed system is a more traditional method of manufacturing that is not used as frequently anymore. This is because the face-sealed system depends heavily on installing perfect seals between glass units and the frame, which often involves caulking. In the long-run, these seals may lose their effectiveness because caulking is not permanent and will break down over time. 

Moreover, it is difficult to achieve perfect sealing. Any imperfections that remain, in the form of holes on the outside surface of the wall, make the system extremely unreliable. 

Another problematic aspect of the face-sealed system is that there is no feature in place to assist in drainage; this, compounded with its moisture-sensitive material is a set-up for dysfunction.

2. Water-Managed System

Water-managed systems are considered the second best structure to use when constructing curtain walls. This is because this system “incorporates drains and weeps from the glazing pocket instead of zone-glazing”.  While these weep holes are great for draining water out of the system, an aspect that the face-sealed system lacks, the water-managed system does not have an air barrier to accompany it. For extra protection, people may choose to opt for the pressure equalizer system.

3. Pressure-Equalizer System

As indicated by its name, the pressure-equalizer system goes one step further in draining water by making the pressure difference between the interior and exterior at a near-zero level. This is done by blocking all external forces that may cross any barrier. Specifically, there lies a wet seal in between the inside of the glass and inside of the glazing pocket, which creates a barrier with no potential to let anything across. 

The outer glass and outer frame are used as a rain screen to direct water away. The pressure-equalization chamber is in between the rain screen, on the outside surface, and the air barrier composed of wet seals, on the inside surface. This chamber reduces all water from entering the premises by making the pressure difference zero. 

Final Words

Curtain walls are a highly efficient, modern, sleek installation that every high-rise, or low-rise, building should seriously consider to appeal to green consumers and avoid pressure from the government. Curtain walls are also the cost-effective choice compared to more traditional alternatives, begging the question – why haven’t you made the switch to curtain walls already?