--- title: "Best window vac for condensation | Home Comfort Lab" description: "A window vac clears morning condensation off the glass and sill. What to look for and which models suit it." url: https://homecomfortlab.co.uk/damp/best-window-vac/ --- # Best window vac for condensation A window vac clears morning condensation off the glass and sill. What to look for and which models suit it. By [Pete Harvey](https://homecomfortlab.co.uk/about/), editor. Updated 14 October 2026. This page links to Amazon. As an Amazon Associate I earn from qualifying purchases. [More about how this site is paid for](https://homecomfortlab.co.uk/affiliate-disclosure/). ![A hand pulls a cordless window vac down a misted window, clearing a stripe through the condensation.](https://homecomfortlab.co.uk/images/scenes/best-window-vac.svg) > **The short answer** > > A cordless window vac sucks condensation off the glass and sill into a small tank, so the water goes down the sink instead of soaking into the frame or back into the air. Pick one whose battery lasts long enough for every window in one go, with a tank you won't have to empty halfway round. ## Why it beats a cloth A cloth fills up after a window or two, and then you're spreading water around the glass. Wet cloths left on a radiator put the water straight back into the room. A window vac collects the water in a tank you empty once, down the sink, so it leaves the house. It also gets into the bottom edge of the frame, where water collects and where black mould starts on the seals. Clearing that line every morning is one of the simplest ways to stop it. See [black mould on window seals](https://homecomfortlab.co.uk/mould/black-mould-on-window-seals/). ## What to look for - **Battery run time.** Long enough to do every window in the house, plus the bathroom tiles or mirror, on one charge. - **Tank size.** On a cold morning with a lot of condensation, a small tank may need emptying before you finish. A bigger tank means fewer trips to the sink. - **Blade width.** A wide blade clears big panes and patio doors in fewer strokes. A narrower one gets into small window panes and the corners of the frame more easily. - **A tank that comes off and rinses out.** Condensation water picks up dust and grime from the frame, so the tank needs a rinse now and then to stay clean. - **Spare or replaceable blades.** The rubber edge wears over time and starts to leave streaks. ## Our picks These are chosen by their specs against the list above. We haven't tested them ourselves; the reasons say which spec puts each one here. ### For most homes Kärcher WV 2 Plus N - **Type:** Cordless - **Tank:** 100ml - **Battery:** 35 minutes Rated to run for 35 minutes on a charge, and battery time is what counts when you do every window in one go. Its tank holds 100ml, so on a very wet morning you may need to empty it once before you finish. [View on Amazon](https://homecomfortlab.co.uk/go/wv-a/) [Manufacturer specs](https://www.karcher.com/gb/en/home-and-garden/products/wv-2-plus-n-p16336510) ### For big windows and patio doors Tower Cordless Window Vac T131001 - **Type:** Cordless - **Tank:** 150ml - **Battery:** 30 minutes The bigger 150ml tank suits large panes, where there's more water to collect before you reach the sink. The battery is rated for 30 minutes, so charge it between uses rather than letting it run low. [View on Amazon](https://homecomfortlab.co.uk/go/wv-b/) [Manufacturer specs](https://xcdn.next.co.uk/pdfs/homeinstructions/G18353.pdf) ## How to use one on condensation 1. Do it first thing, before the water runs down onto the sill and frame. 2. Start at the top of each pane and pull the blade down in overlapping strokes. 3. Run it along the sill and the bottom edge of the frame, where the water collects. 4. Empty the tank into the sink, so the water leaves the house instead of drying back into the room. 5. Rinse the tank now and then, and leave it open to dry. 6. Put it back on charge so it's ready for tomorrow. > **Worth knowing** > > Open the trickle vents, or the window for a short while, after you've cleared the glass. That lets out the damp air that made the condensation in the first place. ## When a window vac isn't enough A window vac clears the water you can see. It doesn't lower the humidity in the room, so if the windows stream every morning, or the walls and corners are damp too, the air needs drying as well. Start with ventilation and a steady background heat, and add a dehumidifier if the room stays damp. [Why windows get wet every morning, and how to stop it](https://homecomfortlab.co.uk/damp/why-are-my-windows-wet-every-morning/). [Dehumidifier size calculator](https://homecomfortlab.co.uk/tools/dehumidifier-size-calculator/): If the windows still stream every morning, find the dehumidifier size that suits your home. ## Read next - [Why are my windows wet every morning?](https://homecomfortlab.co.uk/damp/why-are-my-windows-wet-every-morning/) (How to) Morning condensation means warm, moist air is meeting cold glass. What causes it and how to stop it. - [Black mould on window seals: how to remove it](https://homecomfortlab.co.uk/mould/black-mould-on-window-seals/) (How to) How to clean mould from silicone seals and rubber gaskets, and when the sealant needs replacing. - [Dehumidifier running costs: popular models compared](https://homecomfortlab.co.uk/damp/dehumidifier-running-costs/) (Running costs) What each popular dehumidifier costs per hour and per month at the current price cap, from its rated power. - [Dehumidifier noise and capacity table](https://homecomfortlab.co.uk/damp/dehumidifier-noise-and-capacity/) (Running costs) Every model we list, with its extraction rate, tank size, noise level and power, in one sortable table. --- As an Amazon Associate I earn from qualifying purchases. Links to shops are marked, and earning from them never decides what we recommend. [How this site is paid for](https://homecomfortlab.co.uk/affiliate-disclosure/). Running costs use 26.32p per kWh for electricity and 7.97p per kWh for gas, the [Ofgem price cap, Direct Debit average for England, Scotland and Wales](https://ofgem.gov.uk/news/changes-energy-price-cap-between-1-october-and-31-december-2026) for 1 October to 31 December 2026.