In order to maintain the value of the property, i.e. to avoid visual impairments and damage, regular façade cleaning is essential, as frequent refurbishment (repainting) is neither economically viable nor justifiable from a sustainability perspective.

As the façade area in Germany amounts to several billion m², façade cleaning represents a market with enormous economic potential that can be expanded, but whose development is hindered by complex and sometimes cost-intensive cleaning processes.

The aim of the research project is to develop a blasting process based on plasma-activated ice particles that allows façades to be cleaned and disinfected in a single step, without the use of conventional cleaning chemicals and biocides and with low water consumption.

Water droplets in an aerosol are activated with plasma, frozen with a cryogenic gas and accelerated.

When the plasma-activated ice particles hit the façade, the transferred kinetic energy removes dirt or vegetation; a thin 2-phase layer consisting of water and ice (“slushy” layer) is also formed, in which the reactive species generated during plasma activation of the water are located.

The reactive species kill microorganisms that have not been removed and bleach discolorations.