The clue is in the title….it’s been ten years since Kärcher introduced its first Window Vac for streak-free glass cleaning. Competing with sponge and squeegee for the perfect finish, the Window Vac sucks water from the smooth surface of the window, removing drips and drops, and leaving the glass dry. Sounds like a great a idea, but do windows need a vacuum cleaner? Let’s take a closer look.

The box for this anniversary edition is a marginal step up from the normal six sides of cardboard, with a magnetically closed gatefold showing the evolution of the product from the original in 2008 through to 2018. There’s been six editions of the Window Vac but all remain true to the original from ten years ago with steady incremental changes between each one. This year’s model promises extended battery life….

While this all looks lovely, disappointingly Kärcher haven’t really got their heads round the presentation of the contents of the box – inside everything is higgledy-piggledy. I appreciate that it’s low environmental impact but a bit more organisation would improve that first impression. This is a gadget that has a list price of GB£100 after all.

Setting this to one inside, inside the box is the Window Vac itself, in the usual black and yellow Kärcher combination. There are two wiper blades, one 280 mm and the other 170 mm. These clip in and out of the Window Vac to suit the size of the window being cleaned. To charge up the Vac, there’s a neat AC power adaptor too with a 120 cm cable. There’s a nifty spray bottle which comes with an attachment to take a microfibre cloth, which is actually really handy. Finally, there’s a set of paper manuals and guides, and a small sachet of cleaning concentrate for use with the spray bottle.

The Window Vac is not dissimilar to a handheld vacuum cleaner and it’s surprisingly lightweight – officially it’s 600 g. The two wiper blades clip in and out at the top, there’s a charging port at the bottom, wastewater bottle on the underside and the Vac is designed to sit on its end when not in use. There’s an push on/off button on the handle with an LED which goes solid green when on. The Max line on the water bottle lets you know when it’s time to pour the sucked-up water out by lift out the plug in the top of the bottle. It is possible to remove the top section of the Vac completely, which is handy when you accidentally suck up something a bit larger than usual, such as a leaf.

Looking at the power adaptor, it’s a relatively small unit, sticking out about 6 cm from the wall but with very little height or thickness – it won’t obstruct neighbouring sockets at all. The cable ends in a neat plug which slots into the bottom of the handle. A matching slot and groove stops the connector being put in the wrong way round. Charging from flat is slow, taking several hours – 185 minutes! I found the best approach was to be disciplined and fully charge the Window Vac before putting it away, meaning that vacuum was ready for the next cleaning session.

Before we get to the performance of the Window Vac, I have to give a big thumbs up to the spray bottle and cloth attachment. I don’t know if Kärcher came up with this idea but whoever did, it’s brilliant. Simply, it means that you can spray cleaning solution onto a window (or other surface) and then wipe the liquid over the window with the cloth using just one hand. There’s no squirting-putting-down-picking-up-wiping. It’s excellent and with the spray bottle in one hand and the Window Vac in the other, you’re a window cleaning machine!

So…what’s the Window Vac like in action? I tried it in four scenarios – windows, mirrors, roof windows (Velux) and a shower cubicle. For those who prefer video, here’s my review on YouTube.

For GNC readers, each scenario provided slightly different challenges and associated benefits, and the Kärcher acquitted itself well. For me, the overall big benefit was not the dry, clean and sparkling finish, but that there was no dripping water on the floor or hands getting cold and wet. It’s the package of spray bottle with cloth and Window Vac that is the winning combination. Let’s look in turn at each scenario. By the way, the Window Vac makes very little noise.

Mirrors are easily cleaned with the Window Vac. Typically not really dirty anyway, but quick squirt with glass cleaner and then run over the mirror with the Vac. Gets the liquid off the mirror faster than kitchen towel and less rubbing.

Standard windows. Big benefit over using a squeegee is that the water goes into the Kärcher Vac rather than over your hands and you do get a really good streak-free finish. Obviously it doesn’t clean round the edges of the window frames to get rid of spider webs, so I found the best approach was to go round the window frames with the bucket and sponge first, and then do the window with the Window Vac. In terms of battery life, I cleaned three glass doors and eight windows without any trouble. The specs say 35 minutes, 105 m² or 35 windows.

Roof windows are where the Window Vac really shines. The big problem with Veluxes and similar is that while the window rotates to allow cleaning from the inside, all the muck, dirty and water falls into the room. Normally cleaning is a big hassle with dust sheets but with the Vac, the grubby water gets vacuumed up without hitting the floor. This is a big win for me.

Shower cubicle. Technically the Kärcher worked fine, sucking up the water on the shower cubicle walls and glass door but the value was limited – you’re not worried about water on the floor or streak-free tiles and the Vac needs to be to hand. Squeegee wins in this scenario.

There is one final scenario that didn’t make into the video and only became apparent after recent storms. The Kärcher Window Vac is really good for clearing rainwater off garden trampolines. It sucks up the surface water quickly so that the trampoline can be towelled dry and it’s back to bouncing for the children. Result!

Overall, I’m quite pleased with Kärcher 10 Year Window Vac Anniversary Edition. It makes cleaning windows much easier and is great for roof windows. I have to say that it’s not something I would have though of buying and it’s not an impulse buy with a list price of £99. However, you can easily find it reduced and it’s currently only £49.99 at several online retailers, including Kärcher, which makes it much more reasonable.

Disclosure: I paid the current sale price for the Window Vac as part of The Insiders UK Kärcher campaign.