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Portable air conditioner window seal kit

Updated: 20 October 2026

A hose-vented portable air conditioner only helps if the heat leaves the room. On many UK homes the plastic slider is shaped for a sash or a sideways slider, so the cloth kit whose title says universal is what you are left with. This portable air conditioner window seal kit guide is the order of decisions before the prices on our [air conditioner window seal comparison](/hub/cooling/air-conditioner-window-seal). Those amazon.co.uk prices, from 19 October 2026, run from about £7.99 to £29.99. Peter F. compared the twelve listings and the review notes. It is not a lab test. A qualifying purchase can earn a commission at no extra cost to you. Match the window and the perimeter first.

A hose-vented portable air conditioner only helps if the heat leaves the room.

Our top picks

DREO DREO 400 cm window seal

Best overall

DREO DREO 400 cm window seal
7.3/10about £19.99
View offer
MOEGFY MOEGFY 400 cm seal for AC and dryer

Rank 2

MOEGFY MOEGFY 400 cm seal for AC and dryer
6.8/10about £22.89
View offer
Machine-YA Machine-YA 300 cm window seal

Best value

Machine-YA Machine-YA 300 cm window seal
7.2/10about £16.38
View offer
On this page
  1. 1.What you are buying
  2. 2.Window type first
  3. 3.Length and the hinge side
  4. 4.Zip, dryer hose, and what not to trust

What you are buying

A zip kit is a cloth strip, usually 300 cm or 400 cm, with hook tape and a zip or drawstring for the hose. You leave the sash ajar and stick the tape to the frame. The BTSAE at about £7.99 is a 114 × 113 cm sheet you trim, with a drawstring for a hose up to 15 cm. A rigid panel is a third product and not one of these twelve rows. That choice is on the fabric versus rigid panel page. The zip strip will not be airtight. MOEGFY allows a small gap at the zipper. If a title says universal and never names a window, that fact is missing. The MOEGFY KTB-400CM-New at about £21.99 states a dual hose and does not state the window. The about £22.89 MOEGFY row does.

Window type first

Sort the window before the length. A casement or tilt sash is hinged. A vertical sash and a horizontal slider are a different shape, and the bar in the box was built for them. Appliances Direct treats that slide bar as the sash tool. Four listings say they are not for sliding windows or doors: MOEGFY KTB-400CM, the MOEGFY 300 cm, Machine-YA, and DREO. Derwit says most outward casements and does not exclude sliders. VOLIKRA and LYUNIT do not name a window. A shared MOEGFY review says outward was harder than inward, and OWYR's shared file includes a cantilever uPVC frame that would not take the cloth. If yours is a sash, stop. The geometry is on the casement window seal page.
DREO DREO 400 cm window seal

Testsieger

DREO DREO 400 cm window seal
7.3/10about £19.99
View offer

Length and the hinge side

Measure the sides the cloth will cover, usually three, and skip the hinge. A Machine-YA reviewer says the diagram draws four sides while the seal is built for three. In this set, 300 cm is the maximum on Machine-YA (about £16.38), VOLIKRA (about £15.99), the MOEGFY 300 cm (about £29.99), and the OWYR 300 cm (about £25.99). A top rail of 90 cm and two uprights of 110 cm add to 310 cm, so a 300 cm kit is short of that example. The sum is an illustration, not a survey of UK windows. A 400 cm cloth is baggy on a much smaller window, a repeated MOEGFY comment. Sealey's sheet says not to stick the tape to the glass. That job is on the how to fit page.

Zip, dryer hose, and what not to trust

A double zip lets you place one hose or two. DREO and the OWYR bullets talk about a dual hose. VOLIKRA and the BTSAE sheet close with a drawstring. EGNBU, Machine-YA, and the shared MOEGFY file describe air still moving at the zipper. A dryer hose is stated on Machine-YA, EGNBU, LYUNIT, DREO, both OWYR rows, and two MOEGFY kits. It is not stated on Derwit, VOLIKRA, or the BTSAE sheet. Three MOEGFY listings show 4.0 from 4,220 and the same text. Two OWYR listings show 4.1 from 101 and the same text. Ignore wattage on the cloth: EGNBU prints 1,400 W, and one MOEGFY table prints 1 dB and 1 W. LYUNIT reviewers describe glue perishing around 30°C. If the tape cannot hold the cloth in ordinary use, section 9 of the Consumer Rights Act 2015 treats that as unsatisfactory quality, a route back to the seller.

Common questions

Do you measure three sides or four?
Measure the sides the cloth has to cover. On a hinged window that is usually the top and the two uprights, and you skip the hinge. A Machine-YA reviewer says the diagram draws four sides while the seal is made for three. Add those lengths in centimetres and compare them with 300 cm or 400 cm before you look at the star rating.
Is 300 cm enough for a UK casement?
It is enough when the sides you cover add up to less than 300 cm. It is not a standard size for every casement. A worked example of 90 cm across and 110 cm down each side is 310 cm, which misses a 300 cm kit and fits a 400 cm kit with spare. Measure yours. The listings do not publish one typical UK window.
Which kits say they are not for sliding windows?
Four listings in this comparison say so: MOEGFY KTB-400CM (B087WT2XZF), MOEGFY KTB-300CM, Machine-YA, and DREO. Derwit specifies most outward casements and does not add that sliding line. If the bullets are silent, do not fill the gap yourself. A pictured casement is not proof the cloth suits a slider.
Is the £7.99 sheet the same as a zip kit?
No. The BTSAE is a 114 × 113 cm sheet you cut, with a drawstring and a mesh, rated 2.0 from 18 reviews. Most of the 17 texts say the tape sticks to the frame and not to the fabric. A 400 cm zip strip is a different object. The low price does not make them substitutes.
Can the same kit vent a tumble dryer?
Only where the listing says so. Machine-YA, EGNBU, LYUNIT, DREO, the OWYR rows, and two of the MOEGFY rows name a dryer or an exhaust hose. You still measure the window and the duct. A stated dryer use does not mean the zip locks or the tape survives a hot afternoon.
Why do three MOEGFY listings share 4,220 reviews?
In this export the same 4.0 from 4,220 line and the same review text appear on the 300 cm MOEGFY and both 400 cm MOEGFY ASINs. Treat that as one parent pool. Comments that name 400 cm are not a test of the about £29.99 300 cm cloth. Derwit and DREO have smaller counts that are not copied across lengths in this folder.

Related pages

Best window seal

Air conditioner window seal

Casement window seal for a portable air conditioner

Fabric window seal vs acrylic panel for portable AC

How to fit an air conditioner window seal properly

Sources

Public UK sources from the research digest, used for this page on 20 October 2026. Prices, stars, and review counts are the amazon.co.uk figures in the 19 October 2026 snapshot. NHS and GOV.UK pages do not recommend these kits.

  1. NHS: heatwave, how to cope in hot weather (retrieved 19 October 2026)
  2. GOV.UK: beat the heat, keep cool at home (retrieved 19 October 2026)
  3. Consumer Rights Act 2015, section 9 (retrieved 19 October 2026)
  4. GOV.UK: product safety advice for businesses (retrieved 19 October 2026)
  5. GOV.UK: reporting product safety issues (retrieved 19 October 2026)
  6. Aircon Revolution: window seal kits for portable air conditioners (retrieved 19 October 2026)
  7. Ideal Home: portable air conditioner window kits (retrieved 19 October 2026)
  8. Appliances Direct: how to install home air conditioning (retrieved 19 October 2026)