Window cleaning of tall buildings is manual performed by window cleaners. They use a sponge with a squeegee. Reaching the glass on tall buildings is a challenge for window cleaners. A hundred years ago a boatman’s chair was used. A boatman’s chair is nothing more than a plank on a vertical cable, like a swing chair. The window cleaner sits on the plank and is suspended with a cable from the roof. In the Netherlands this method is forbidden, because it is too dangerous.
Another tool for window cleaning of tall buildings is an aerial platform, also called cherry picker. An aerial platform is a wagon with a telescopic or articulated arm with at the end a platform for the window cleaner. Nowadays there are aerial platforms with a height of 100 meters and more, but window cleaning from these platforms is very difficult. You must position the platform close to the glass (<0.5 meters), but you do not want to bump into the facade and cause damage. And that is very difficult with a vertical arm of 100m: a small change at the base results in a large change of the platform. For buildings up to 20-25 m an aerial platform works fine, but higher is not preferred. When using an aerial work platform, you need to be sure that the ground is reinforced and stabilised, and that all parts of the façade are accessible. There is an increasing number of cities where you need to apply for a permit to use an aerial platform.
Window cleaning installation
For tall buildings a window cleaning installation (also called: façade maintenance installation or window cleaning lift) is installed on a building. Probably you know them: on tall buildings you often see a crane with a platform. This is a window cleaning installation. A window cleaner stands on the platform of the window cleaning installation and lowers himself along the façade via the crane. He makes vertical tracks, all the way down, then up again, and then to the next track. The window cleaning installation moves horizontally via a rail track on the roof. Instead of rails a fixed window cleaning installation can be used. Then this installation can rotate and via the telescopic arm it is able to reach the facade. When choosing a window cleaning installation, it is important to check whether there is enough roof surface to install the crane. The structure of a tall building must often be reinforced to properly withstand the large forces exerted by such an installation. The investment in a window cleaning installation is high, and you still need to clean the glass manually.
Today, many new buildings are so tall, large or complex that the conventional window cleaning method cannot be used. In that case, developers and architects choose often the mountaineer method, mainly due to investment or inaccessibility reasons. This method is also known as industrial climbers or rope access. The window cleaner abseils from top to bottom and cleans the building. In the Middle and Far East this method is quite normal: crews of 15 rope climbers and more clean the windows, hanging side by side suspended from the roof of a tall building.
This method is prohibited in the Netherlands and the rest of Europe.
The new method to clean tall buildings is robot window cleaning. In every sector dangerous and physically work is automated. It is only a matter of time before robot window cleaning is widely accepted. We truly believe that robotic window cleaning will become the standard in 10 years from now.
Besided the safety benefits robotic window cleaning introduces economic and sustainable benefits as well: a Kite Robot saves 80% on maintenance costs and 85% on energy consumption. More information is available at Kite Robotics.
The Kite Robot cannot only be used on smooth glass facades, but facades with vertical or horizontal indentations are suitable as well. The Kite Robots can handle a whole range of building geometries, including deep horizontal and/or vertical recesses, buildings composed of glass and other cladding, as well as glass roofs. Examples are available at references.