The seal that decides whether the BTU rating means anything

The best portable AC window venting kits for 2026

The kit bundled with a portable air conditioner is nearly always designed for a sliding sash window, and a large share of European windows tilt, turn or crank outward instead — which is precisely why this hub exists as its own family rather than a footnote on the appliance page. A poorly sealed gap around an improvised vent lets warm outdoor air back in continuously, quietly erasing much of the machine's rated cooling capacity. We compare window-type fit, compatibility with the hose diameters actually sold by major portable AC brands, and seal material — foam, brush strip or a rigid panel each suit a different frame shape.

What we recommend

1. 

   HOOMEE Universal Window Seal 400CM

   HOOMEE's fabric window seal closes the gap left by a portable air conditioner's exhaust hose, up to a window perimeter of 400 cm (157 in), fastened with adhesive hook tape and a zip that closes around the hose itself. HOOMEE markets it as fitting any portable air conditioner or tumble dryer, not one named brand or model.

   Window perimeter

   Up to 400 cm (157 in), per HOOMEE

   Fitting

   Adhesive hook tape on the frame and window, no drilling

   Hose seal

   Zip closure around the exhaust hose

   Item weight

   403 g, per the Amazon US listing

   Amazon reference

   B07BPZGJ3B (identical on DE/FR/IT/ES/US; listed with no active offer on GB at time of writing)

   EAN

   0708315566043

   • Confirmed with a valid New-condition price on five markets (DE, FR, IT, ES, US), and the cheapest of the three window kits reviewed on this site
   • Strong sales rank on Amazon.fr specifically (#521 in its category at time of checking), pointing to real sales volume rather than a listing that merely exists
   • The same ASIN is listed on Amazon UK but had no active offer at the time of checking — present in the catalogue is not the same as available to buy

   Best for: A single-hose portable air conditioner at an irregular or non-standard window, where a flexible fabric seal covers more window shapes than a rigid kit.

   ≈ 20 €

   Check price on Amazon
2. 

   De'Longhi DLSA012

   De'Longhi's own window kit: a strip that seals the gap around a portable air conditioner's exhaust hose, rated for window perimeters between 270 and 390 cm and fitted with adhesive hook-and-loop tape rather than screws. De'Longhi describes it as compatible with any mobile air conditioner that uses an exhaust hose, not only its own Pinguino range.

   Window perimeter

   270–390 cm, one or two casement/tilt windows or a sliding window

   Fitting

   Self-adhesive hook-and-loop tape, no drilling

   Material

   Water-resistant, wipeable fabric, per De'Longhi

   Amazon reference

   B092JHF4T3 (identical on DE/FR/IT/ES/GB; not listed on Amazon US)

   EAN

   8004399021129 / 8713411250118

   • From an appliance brand rather than an unbranded seller, with the same ASIN confirmed for sale on five markets (DE, FR, IT, ES, GB)
   • No-drill hook-and-loop fitting, and De'Longhi states the window stays fully usable — opened, tilted or closed — once it's fitted
   • No published hose-diameter figure — check your unit's hose against the kit's opening before buying

   Best for: A single-hose portable air conditioner near a hinged or sliding window with a perimeter between 270 and 390 cm, where a no-drill fit matters more than price.

   ≈ 26 €

   Check price on Amazon
3. 

   RIRIDAMAI PVC Window Plate Kit (150mm)

   RIRIDAMAI's window kit is four rigid PVC and ABS panels rather than a fabric sheet, adjustable by nut from 43 to 140 cm to match the window's opening, and built around a 150 mm exhaust-hose opening. RIRIDAMAI states it's designed for sliding windows specifically, fitted into the window track without tools.

   Adjustable range

   43–140 cm per panel, set with a nut

   Panel width

   16 cm each; 2 to 4 panels used depending on window size

   Hose opening

   150 mm, per RIRIDAMAI

   Material

   PVC + ABS, stated heat- and wear-resistant

   Amazon reference

   B0GJYJ9Y1W (identical on DE/FR/IT/ES; not found on Amazon US or GB)

   EAN

   Not published

   • Confirmed with a valid New-condition price on four markets (DE, FR, IT, ES)
   • Rigid PVC+ABS panels rather than fabric — a different mounting method to the two cloth kits also reviewed on this site, and one better suited to a sliding-window track
   • Not found as a listing on Amazon US or Amazon UK at the time of checking

   Best for: A sliding window paired with a single-hose unit that has roughly a 150 mm exhaust outlet, where a rigid, track-mounted panel suits the window style better than a fabric sheet.

   ≈ 25 €

   Check price on Amazon