Window-Cleaning Robot clearBee Leaves Die Höhle der Löwen Empty-Handed After Demo Meltdown
Published on 09/20/2026 at 23:10 | Editorial boerse-global.de
Five investors, one pitch, zero takers. That was the outcome for Vienna-based startup clearBee when it brought its automated window-cleaning concept to Vox's "Die Höhle der Löwen" on 21 September at 20:15, offering ten percent of the company for 300,000 euros.
Williams, Ensthaler, Dümmel, Thelen and Herb — every one of the five potential backers in the room — turned the deal down.
A demo that never got off the ground
According to a 20 September 2026 report on netzwelt.de, the on-camera demonstration went badly wrong. The flying device only grazed the test pane, the system ignored spoken commands, and the docking station contained no cleaning agent at all.
The founders say they have already sunk 450,000 euros into development. Their system is sold in pieces: an adapter runs 249 euros, while the version bundled with a charging station costs 549 euros. No drone is included in that package. The manufacturer puts battery life at 40 minutes.
What automated glass cleaning can and cannot do
The appeal of technical aids for windows is straightforward — less manual labour in building maintenance, less physical strain on the people doing it.
A homeandsmart.de report from 19 September 2026 identifies where automated solutions pay off: large glass surfaces, conservatories, hard-to-reach glazing, and situations involving physical limitations or a regular cleaning schedule.
They are a poorer fit for windows with muntins or frames, for many small window fronts, and for anyone demanding a completely streak-free finish.
Common weak points among conventional window-cleaning robots include dirty corners and edges, a tendency to leave streaks, and the need for manual pre-cleaning. Off-the-shelf devices generally sit in a price range of 150 to 600 euros.
Established rivals, and the physics of cleaning overhead
Several proven alternatives already occupy the rope- or suction-based cleaning robot market, each with its own performance profile. In March 2026, a product test named the ECOVACS WINBOT W3 OMNI its winner with a grade of Good (90/100), priced at 549 euros instead of the regular 699 euros.
February 2026 saw the Dreame C1 Station take the value-for-money title with Good (88/100) at 399 euros rather than 599 euros. The cheapest option was the MOVA N1 at 249 euros, graded Good (82/100). The previous year's champion, the ECOVACS WINBOT W2 OMNI, scored Very Good (92/100) in February 2024 and cost 424 euros instead of 599 euros.
Existing devices run into hard physical limits, especially when working overhead: no current model can autonomously clean horizontal surfaces at 0 degrees above head height. The Ecovacs Winbot W3 Omni and W2S Omni handle undersides from an angle of 40 degrees to the horizontal, though the W2S Omni's datasheet specifies 60 to 120 degrees.
The Dreame C1 Station only manages undersides from 60 degrees and tops from 10 degrees. The MOVA N1 works overhead from 5 degrees using the remote control alone, and only cleans autonomously from 60 degrees.
Most recently, Ecovacs showed the WINBOT W2S PRO OMNI at Berlin's IFA (4 to 8 September), and on 9 September the model picked up the home&smart Innovation Award 2026 in the window-cleaning robot category. It offers 10,000 Pa of suction, four corner scrubbers, a TruEdge 2.0 system and a 120-millilitre water tank covering roughly 75 square metres.
A 4,500 milliamp-hour battery in the station allows cordless operation for up to 110 minutes at a noise level of 66 decibels. The device handles tilted panes up to 45 degrees and has been available in Germany since 9 September at a recommended retail price of 599 euros.
