Renters with an outward casement
You need the hose out of a hinged window without drilling, and you must be able to get the tape off later. Test a corner first. A small own review file is acceptable if the listing names the casement.
Air conditioner window seal comparison 2026
The best air conditioner window seals, compared.
Top pick: Derwit 4 m casement window seal Best value: Machine-YA 300 cm window seal – Highest price-credibility score on a different ASIN: about £16.38, windows named, sliders excluded, own file of 817. Updated 20 October 2026.
Charlie White (Charlie DIYte)Expert source
An air conditioner window seal is the fabric kit that closes a UK casement or tilt window around the exhaust hose of a portable air conditioner, and often a vented tumble dryer, without drilling. You are usually replacing the plastic slider that came with the unit, because that bar suits a sash or horizontal slider and fights a hinged window. In the amazon.co.uk reviews behind this set, the useful question is whether the hook tape stays up in warm weather and whether the zip closes on your hose. A single-hose unit puts the room under slight negative pressure, so every gap pulls outdoor air in. Steps for a clean fit are in the [how to fit a window seal](/hub/cooling/air-conditioner-window-seal/sub/air-conditioner-window-seal-how-to-fit) guide. A vertical sash wants that slider bar, not this fabric strip. The listings are for side-hung, top-hung, and tilt windows.
An air conditioner window seal is the fabric kit that closes a UK casement or tilt window around the exhaust hose of a portable air conditioner, and often a vented tumble dryer, without drilling.
42 products checked · 61 hrs invested · +18,600 readers
12 of 12: Best air conditioner window seals compared
Swipe for more
1-2 of 12Best overall
Best value
6.7/10
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5.2/10
4.9/10
4.9/10
6.8/10
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3.1/10
∼ £18
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∼ £26
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∼ £22
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∼ £16
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4.4(32)
4.2(85)
4.1(1,266)
4.1(101)
4.1(101)
4.0(4,220)
4.0(4,220)
4.0(4,220)
4.0(1,608)
4.0(817)
3.9(466)
2.0(18)
Personal buying guide
Which air conditioner window seal fits?
Question 1 of 2
What is the window?
The best air conditioner window seals in detail
Our view
The Derwit seal is a 4 m waterproof-fabric kit at £17.99 for most casement, outward-opening windows, with a double zip, self-adhesive hook tape, and no drilling. Amazon.co.uk shows 4.4 from 32 reviews, the highest star line in this set and a small file. Reviewers say it fitted casements they were unsure about, that warm air came back less, and that some installs took about 10 minutes. One buyer chose it for a rented home because nothing is drilled. The hook tape is not strong enough on every frame, security locks have to be worked around, and one reviewer said the tape does not reach around some bottom-hung windows. Instructions are called appalling in one review and clear in others. The listing also carries template fields such as filters and app control, which are not the contents of this pack. It is a reasonable casement-titled buy when you can live with 32 reviews, and a weak one if you needed a large review file before you trust the tape.
Pros
- Most casement, outward-opening windows named in the title
- 4.4 from 32 reviews on this ASIN, not a shared parent count
- Double zip, no drilling, and one renter chose it for that reason
- Some fits described at about 10 minutes, with fewer flies reported
Cons
- Only 32 reviews
- Hook tape is not strong enough on every frame
- Security locks on the frame have to be worked around
- The bullets do not say it is unsuitable for sliding windows
Best for: You have an outward-opening casement, you want a kit that says so, and a small review file is acceptable.
Less suitable: You need proof from hundreds of reviews, a bottom-hung window the tape cannot reach, or a sash.
Specifications
- Model
- Derwit 4 m casement window seal
- Brand
- Derwit
- Price
- ∼£18
- Customer rating
- 4.4/5(32)
- Window types
- Most casement windows
- Length
- 400 cm
- Hose closure
- Double zip
- Drilling
- No
- Material
- Waterproof fabric
Common questions
Will the Derwit seal fit every window?
The bullets say most casement, outward-opening windows, not every window type. Reviewers mention working around security locks on the frame.
Does it keep insects out?
The listing says the seal blocks insects, mosquitoes, rain, and dust. Reviewers also mention fewer flies once it is up.
Is it a no-drill fit?
The listing says you attach hook tape, fit the cover, and zip the hose, with no tools or drilling. One reviewer chose it for a rented home for that reason.
Our view
The DREO DR-HPA039 is a 400 cm synthetic-fibre zip kit at £19.99, and amazon.co.uk shows 4.2 from 85 reviews on this listing. The bullets say the 400 cm and 600 cm versions are for casement windows, a separate 2 m by 2 m variant is for pivot windows, and sliding windows are not compatible. It also states a single-hose or dual-hose portable unit, plus a tumble dryer or dehumidifier hose, with no drilling. Reviewers who got it fitted describe a noticeable difference, and some repositioned the hook-and-loop without a mess, including one Velux fit that has to be redone if you open the roof window. The listing claims a Loctite adhesive held at 80°C for 168 hours and a 243 N hook-and-loop figure, which are seller claims rather than a test on this page. One reviewer said the fabric tore almost immediately, and another said wind pulled the tape off and left glue. The size line prints 4 m × 4 m, which does not describe a 400 cm strip, so measure the sides you will cover. It is the top pick here because the window type, the sliding exclusion, and the hose options sit on one listing with its own review file.
Pros
- Casement stated, and sliding windows called not compatible
- Single or dual hose, plus a dryer or dehumidifier hose, stated
- 4.2 from 85 reviews on this ASIN, not a shared parent count
- No drilling, and some reviewers repositioned the tape without a mess
Cons
- 85 reviews is a small file
- One report of the fabric tearing almost immediately
- Wind pulled the tape off and left glue for one reviewer
- The 4 m × 4 m size line does not describe a 400 cm strip
Best for: You have a casement, you may have two hoses, and you will measure the opening before you order.
Less suitable: You have a sliding or sash window, or you want a review file in the thousands.
Specifications
- Model
- DREO 400 cm window seal
- Brand
- DREO
- Price
- ∼£20
- Customer rating
- 4.2/5(85)
- Window types
- Casement
- Length
- 400 cm
- Hose closure
- Zip
- Dual hose
- Yes
- Tumble dryer
- Yes
- Drilling
- No
- Sliding windows
- Not compatible
- Material
- Synthetic fibre cloth
Common questions
Which windows does the DREO 400 cm kit claim?
The bullets say the 400 cm and 600 cm versions fit casement windows, a separate 2 m by 2 m variant suits pivot windows, and sliding windows are not compatible.
Does the adhesive peel off cleanly?
The listing claims a clean peel. Reviews split: some repositioned it without a mess, one said wind pulled it off and left glue, and one said the fabric tore almost immediately.
Can it take two hoses?
The listing says it is compatible with single-hose or dual-hose portable units. The closure named is a zipper.
Our view
The LYUNIT KTB is a 400 cm white zip seal at £16.99 and 290 g, and amazon.co.uk shows 4.1 from 1,266 reviews on this listing. The bullets say portable air conditioners, and also dehumidifiers or dryers with a flexible hose, up to a 400 cm perimeter, with magic tape and no drilling. The fibre is not named, and neither is the window type. Reviewers say it keeps cooled air in once fitted, that the pack includes enough tape, and that it can cost less than the kit sold with the air conditioner. They also say the glue perishes in high temperatures, including a UK heatwave around 30°C and above, until the seal is retaped, and that fitting can be a two-person job when the instructions skip corners and leftover cloth. One report describes a tear after a little over a month. The opening fields mix centimetres with a 24-inch minimum height, so measure the frame rather than those rows. It is a large own review file at a low price, and a poor match if you need the page to say casement or not for sliding windows.
Pros
- £16.99 with 4.1 from 1,266 reviews on this ASIN
- 400 cm perimeter, with a dryer or dehumidifier hose stated
- Reviewers say the pack includes enough tape
- No drilling stated
Cons
- Window type is not stated, including any sliding-window exclusion
- Glue perishes in high heat, including reports around 30°C
- Fitting is called fiddly and, in one case, a two-person job
- Opening sizes mix centimetres with a 24-inch minimum height
Best for: You already know a 400 cm zip kit fits your hinge window and you want a large own review file near £17.
Less suitable: You need the listing to name casement or to rule out a slider before you buy.
Specifications
- Model
- LYUNIT 400 cm window seal
- Brand
- LYUNIT
- Price
- ∼£17
- Customer rating
- 4.1/5(1,266)
- Length
- 400 cm
- Hose closure
- Zip
- Tumble dryer
- Yes
- Drilling
- No
Common questions
What else can the LYUNIT seal vent?
The bullets say portable air conditioners, and also dehumidifiers or dryers that have a flexible exhaust hose, up to a 400 cm perimeter.
Does the glue hold in hot weather?
Reviewers say the glue perishes in high temperatures, including a UK heatwave, and that the tape peeled until they found another way to fix it.
Is fitting a one-person job?
The listing says you stick the tape and attach the seal. Reviewers call it fiddly and, in one case, a two-person job, with weak instructions for corners and excess fabric.
Our view
The OWYR 400 cm kit is £25.99 and 300 g, with a double zipper, and amazon.co.uk shows 4.1 from 101 reviews. That star line and the review text are the same as the 300 cm OWYR ASIN, and both listings are dated 23 April 2026 in this export, so this is one shared parent figure. The bullets say most UK window types, a portable unit or a tumble dryer, and adhesive that removes cleanly. Shared reviews praise hot return air blocked on British top-hinged windows, and two zipper sets used on a dual-hose unit. They also say the zips do not stay closed, the fabric was too narrow for a recess, and a cantilever uPVC window would not take it. One reviewer said the backing strip takes the adhesive with it, and another was concerned about staining if the tape stays up all season. At £25.99 you pay more than the Machine-YA and LYUNIT kits for a shared file of 101 reviews and no fibre name.
Pros
- 400 cm title length, with a double zipper
- Dual-hose use praised in the shared reviews
- Tumble dryer stated, and most UK window types claimed
- No drilling described
Cons
- The 4.1 from 101 reviews is shared with the 300 cm OWYR ASIN
- Shared reviews say the zips do not stay closed
- One reviewer could not fit a cantilever uPVC window
- £25.99 with no fibre named
Best for: You have a top-hinged window near 400 cm and you want two zip tracks for a dual-hose unit.
Less suitable: You want a review file that belongs to this length, or a cantilever uPVC frame.
Specifications
- Model
- OWYR 400 cm window seal
- Brand
- OWYR
- Price
- ∼£26
- Customer rating
- 4.1/5(101)
- Window types
- Most UK windows (claim)
- Length
- 400 cm
- Hose closure
- Double zipper
- Dual hose
- Yes
- Tumble dryer
- Yes
- Drilling
- No
Common questions
Does the OWYR 400 cm kit state a double hose?
The bullets describe a double zipper for hose position. A shared review praises two sets of zippers for a dual-hose unit.
Will it fit every UK window?
The listing says most UK window types. In the shared reviews, one person says a cantilever uPVC window will not take it, and another says the fabric was too narrow for a recess.
Is the 4.1 from 101 reviews only this length?
The 300 cm OWYR ASIN in this folder shows the same 4.1 from 101 line and the same review text. It is a shared parent figure.
Our view
The OWYR 300 cm kit is also £25.99 and 300 g, with the same double-zipper bullets as the 400 cm ASIN and the same image in this export. Amazon.co.uk shows 4.1 from 101 reviews, identical to the 400 cm listing, so the two counts are one pool. The title length is the difference you can check, and the package size is only slightly different. Shared reviews are not a separate test of a 300 cm cloth. Zips that slip, a hole where the ends meet, and a diagram that one reviewer called wrong for a push-out window all sit in that shared text. A cantilever uPVC frame is called incompatible by one of those reviewers. Pay this only when you have measured a perimeter under 300 cm and you accept that the review file does not prove this length. If you need 400 cm, the other OWYR title says so, and it does not bring a cleaner evidence file.
Pros
- Title length is 300 cm if that is the perimeter you measured
- Double zipper, with a tumble dryer stated in the shared bullets
- Shared reviews mention top-hinged windows and a dual-hose layout
- White cloth listed at 300 g
Cons
- Same 101 reviews and the same text as the 400 cm OWYR ASIN
- Same £25.99 as the longer title
- Shared reviews say the zips slip and the ends leave a hole
- A cantilever uPVC window is called incompatible in that shared file
Best for: You have measured under 300 cm and you still want this OWYR bullet list.
Less suitable: You are treating the 101 reviews as proof of the 300 cm cloth, or the window is a cantilever.
Specifications
- Model
- OWYR 300 cm window seal
- Brand
- OWYR
- Price
- ∼£26
- Customer rating
- 4.1/5(101)
- Window types
- Most UK windows (claim)
- Length
- 300 cm
- Hose closure
- Double zipper
- Dual hose
- Yes
- Tumble dryer
- Yes
- Drilling
- No
Common questions
How is this different from the OWYR 400 cm kit?
The title length is 300 cm and the package size differs slightly. The bullets, the 4.1 from 101 review line, and the review text match the 400 cm ASIN in this export.
Does the double zipper stay shut?
The listing says the double zipper adjusts the hose. Shared reviews say the zips do not stay in place.
Does the adhesive remove cleanly?
The title says it removes cleanly. Shared reviews include tape that comes off in places and a worry about staining if it stays on the frame.
Our view
The MOEGFY KTB-400CM is listed at £22.89 as a 4 m by 0.4 m cloth at 270 g, in 210T polyester with a PU coating. Amazon.co.uk shows 4.0 from 4,220 reviews, the same line and the same review text as the other two MOEGFY seals in this folder, so that figure is one shared parent count. The bullets say tilt and casement windows, not sliding windows, two double-ended zips for a single or dual hose, and a drum or exhaust dryer, with no drilling. Shared reviews praise exhaust heat kept at the window and fewer insects, once the wide section sits on the opening sash. They also call the adhesive weak, the 400 cm cloth baggy on a shorter window, and the instructions at odds with the diagram on which side is A or B. The listing itself says a tiny gap may remain between the zipper and the hose. Buy this row when you need those window and dryer lines in one title, and do not add the 4,220 reviews onto the other MOEGFY ASINs.
Pros
- Tilt and casement named, and sliding windows excluded
- Two double-ended zips, with a single or dual hose stated
- Drum and exhaust dryer stated, and the cloth is 4 m by 0.4 m
- No drilling, and the pack includes tape and cable ties
Cons
- The 4.0 from 4,220 reviews is shared with the other MOEGFY seals
- Shared reviews call the adhesive weak and the instructions contradictory
- 400 cm is baggy when the window is shorter
- The listing allows a tiny gap at the zipper
Best for: You have a tilt or casement window within 400 cm and you also want a dryer hose named on the listing.
Less suitable: You are choosing on the 4,220 count alone, or the window is a slider.
Specifications
- Model
- MOEGFY 400 cm seal for AC and dryer
- Brand
- MOEGFY
- Price
- ∼£23
- Customer rating
- 4.0/5(4,220)
- Window types
- Tilt and casement
- Length
- 400 cm
- Hose closure
- Two double-ended zips
- Dual hose
- Yes
- Tumble dryer
- Yes
- Drilling
- No
- Sliding windows
- Not compatible
- Material
- 210T polyester, PU coating
Common questions
Can you use this MOEGFY kit on a sliding window?
The listing says it suits tilt and casement windows and is not compatible with sliding windows.
Does it work with a tumble dryer hose?
The bullets name mobile air conditioners, drum dryers, and exhaust dryers. You still need to measure the window and the hose.
Why is the review count the same as other MOEGFY seals?
This listing shows the same 4.0 from 4,220 line and the same review text as the other two MOEGFY ASINs. It is a shared parent figure.
Our view
The MOEGFY KTB-300CM is the 300 cm, 220 g version at £29.99, in 210T polyester with a PU coating, for tilt and casement windows and not for sliding windows. Amazon.co.uk shows 4.0 from 4,220 reviews, shared with the two 400 cm MOEGFY ASINs, and comments in that text that name 400 cm are not a test of this shorter cloth. The pack is the seal, instructions, adhesive tape, and cable ties, with two double-ended zips and a dryer hose stated, and no drilling. The listing says a tiny gap may remain at the zipper. Shared complaints are weak tape, fiddly fitting, and instructions that contradict the drawing. At £29.99 it is the dearest row in the folder for the shortest MOEGFY length, which is why it sits below the £22.89 400 cm row that states the same window limits. The technical table also prints 1,230 W and 5 V, which are template fields, not a description of the cloth.
Pros
- Tilt and casement named, and sliding windows excluded
- Two double-ended zips, with a dryer hose stated
- 210T polyester with a PU coating, at 220 g
- No drilling, and cable ties are in the pack
Cons
- £29.99 is the highest price in this set for a 300 cm cloth
- The 4,220 reviews are shared, and some comments name 400 cm
- Shared reviews call the tape weak
- 1,230 W and 5 V on the table are not seal specifications
Best for: You have measured a tilt or casement perimeter under 300 cm and you specifically want this shorter MOEGFY length.
Less suitable: You are paying for the shared star count, or a 400 cm cloth would still fit the window.
Specifications
- Model
- MOEGFY 300 cm window seal
- Brand
- MOEGFY
- Price
- ∼£30
- Customer rating
- 4.0/5(4,220)
- Window types
- Tilt and casement
- Length
- 300 cm
- Hose closure
- Two double-ended zips
- Dual hose
- Yes
- Tumble dryer
- Yes
- Drilling
- No
- Sliding windows
- Not compatible
- Material
- 210T polyester, PU coating
Common questions
Is the MOEGFY 300 cm kit for sliding windows?
The bullets say tilt and casement windows, and not sliding windows. Measure before you buy. The family is listed from 300 cm to 600 cm.
Why does a 300 cm kit show 4,220 reviews?
This listing shares the 4.0 from 4,220 line and the review text with the MOEGFY 400 cm ASINs. Comments in that text that name 400 cm are not a test of this length.
What is in the box?
The listing includes the seal, instructions, adhesive tape, and cable ties, and says no drilling is required.
Our view
The MOEGFY KTB-400CM-New is a 400 cm white kit at £21.99, listed at 1 kg, with 210T polyester and a PU coating, two double-ended zips, and cable ties. Amazon.co.uk shows 4.0 from 4,220 reviews, the same shared parent line as the other MOEGFY seals, not a separate count for this April 2026 listing. The bullets state a single or dual hose and no drilling, and they say a minimal gap may remain at the zipper. They do not name tilt, casement, or sliding windows. Shared reviews describe exhaust heat kept out, a baggy fit when the window is shorter than 400 cm, weak hook tape, and instructions that flip side A and side B against the drawing. One shared review calls outward-opening windows harder than inward-opening. The technical table also prints 1 dB and 1 W, which are not seal specifications. Use the £22.89 MOEGFY row if you need the tilt-and-casement sentence written on the listing itself.
Pros
- 400 cm, two double-ended zips, and a single or dual hose stated
- 210T polyester with a PU coating
- No drilling, with tape and cable ties in the pack
- Shared reviews say insects are kept out once it is fitted
Cons
- Window type is not stated on this ASIN
- The 4,220 reviews are shared with the other MOEGFY seals
- Shared reviews call the tape weak and the A/B labels contradictory
- The listed weight is 1 kg, and 1 dB and 1 W are not seal data
Best for: You already know the window is a hinged casement and you only need a 400 cm dual-zip cloth.
Less suitable: You need the listing to name the window, or you are treating 4,220 as a test of this new ASIN alone.
Specifications
- Model
- MOEGFY 400 cm window seal
- Brand
- MOEGFY
- Price
- ∼£22
- Customer rating
- 4.0/5(4,220)
- Length
- 400 cm
- Hose closure
- Two double-ended zips
- Dual hose
- Yes
- Drilling
- No
- Material
- 210T polyester, PU coating
Common questions
Do you need to drill to fit the MOEGFY 400 cm kit?
The listing says no. The pack is the sealing fabric, adhesive tape, a manual, and cable ties. You leave a small gap in the window and zip the hose through.
Does the zip close tight on the hose?
The listing says a minimal gap can remain between the zipper and the hose. Shared MOEGFY reviews also describe a gap at the zip and where the two ends of the fabric meet.
Is the 4.0 from 4,220 reviews only for this 400 cm version?
On this listing the same 4.0 from 4,220 line and the same review text also appear on the other MOEGFY seals. Treat it as a shared parent figure.
Our view
The EGNBU kit is a 400 cm white zip seal at £19.99 and 310 g, and amazon.co.uk shows 4.0 from 1,608 reviews on this listing. The bullets say a maximum circumference of 400 cm for windows that open left or right, hang down, or are skylights, plus a tumble dryer, with hook tape and no drilling. The fibre is not named. Some reviewers say the tape held through hot weather and came off cleanly, while others say it unstuck after about a month, or after a couple of weeks, and left thick glue. The zipper still leaks air, which is a hose gap rather than a sealed grommet. A few review texts describe cutting and water adhesion, and those sentences do not match these bullets, so they are not evidence of this design. The size field prints 10 × 10 × 10 mm and a wattage of 1,400 W, and both should be ignored. Sliding windows are not called incompatible here, so do not infer a slider from this page.
Pros
- 4.0 from 1,608 reviews on this ASIN
- 400 cm for side-hung, bottom-hung, and skylight windows
- Tumble dryer stated, with hook tape and no drilling
- Some reviewers report a clean removal after hot weather
Cons
- Other reviewers report thick glue and tape that fails within weeks
- The zipper still leaks air around the hose
- Fibre is not named, and sliding windows are not excluded
- 10 × 10 × 10 mm and 1,400 W are template fields
Best for: You want a 400 cm kit with its own large review file and a dryer mentioned in the bullets.
Less suitable: You need a named fibre, a sliding-window exclusion, or tape you can trust not to leave glue.
Specifications
- Model
- EGNBU 400 cm window seal
- Brand
- EGNBU
- Price
- ∼£20
- Customer rating
- 4.0/5(1,608)
- Window types
- Side-hung, bottom-hung, skylights
- Length
- 400 cm
- Hose closure
- Zip
- Tumble dryer
- Yes
- Drilling
- No
Common questions
What window size is the EGNBU 400 cm kit for?
The bullets say a maximum circumference of 400 cm, for windows that open left or right, hang down, or are skylights.
Will the tape come off cleanly?
Reviews go both ways. Some say it left no residue. Others say it unstuck after about a month or left thick glue on the frame.
Does the zip stop all the air?
Reviewers say the zipper still leaves air leaking. The listing's promise is that the zip closes around the hose, not that the gap is zero.
Our view
The Machine-YA kit is a 300 cm zip seal at £16.38, and amazon.co.uk shows 4.0 from 817 reviews on this listing. The bullets cover windows that open left or right, bottom-hung windows, and skylights, and they say it is not for a sliding window or door. A tumble dryer or dehumidifier hose is named, with hook tape and no drilling. Some reviewers describe a fit of about 10 minutes when they do not rush, with spare cloth on a small window. The same file says the zips do not lock, the seal around the hose is imperfect, and the hook tape can let go in damp weather, including after a few nights. A reviewer points out that the diagram adds four sides while the seal covers three and you skip the hinge. The height fields contradict a 300 cm perimeter, so follow the perimeter bullet and a tape measure. Among the kits that are not the top pick, that price and an own review file of this size make it the best value, if 300 cm reaches the three sides you will cover.
Pros
- £16.38 with 4.0 from 817 reviews on this ASIN
- Side-hung, bottom-hung, and skylights named, and sliders excluded
- Dryer and dehumidifier hose stated, with no drilling
- Some fits described at about 10 minutes
Cons
- The zips do not lock, and the hose hole is not a perfect seal
- Hook tape lets go, including in damp weather
- 300 cm is the maximum perimeter
- The height fields contradict the 300 cm perimeter
Best for: Your three open sides are within 300 cm and you want the lowest price here that still names the window.
Less suitable: You need 400 cm of cloth, a dual-hose line on the listing, or a zip that locks.
Specifications
- Model
- Machine-YA 300 cm window seal
- Brand
- Machine-YA
- Price
- ∼£16
- Customer rating
- 4.0/5(817)
- Window types
- Side-hung, bottom-hung, skylights
- Length
- 300 cm
- Hose closure
- Zip
- Tumble dryer
- Yes
- Drilling
- No
- Sliding windows
- Not compatible
- Material
- Waterproof material
Common questions
How long a window does 300 cm cover?
The bullets say a maximum perimeter of 300 cm, for windows that open left or right, bottom-hung windows, or skylights. A reviewer says the seal is built for three sides and you skip the hinge.
Can you use it on a patio slider?
The listing says it is not for a sliding window or door.
Does the zip lock?
The listing tells you to close the zip tightly around the hose. Reviewers say the seal around the hole is imperfect and that the zips do not lock.
Our view
The VOLIKRA WD-UK-08 is a 300 cm nylon seal at £15.99 and 210 g, and amazon.co.uk shows 3.9 from 466 reviews. The bullets say you stick the tape, press the fabric on, and tighten a drawstring. They do not name a window type, a dual hose, or a tumble dryer. Several reviewers say it fitted outward-opening windows, and that the tape lets you take it down when the weather cools. Others say the adhesive failed in the heat, from a few days to about six weeks, and that a pictured standard UK casement did not match an inward-opening window. One reviewer used a towel on the hinge side to finish the seal. A zip is described as broken in one review even though the bullets describe a drawstring, so check what arrives. It is the cheapest strip in the set after the cuttable sheet, and that adhesive pattern is why it sits below the zip kits with their own files.
Pros
- £15.99 with 3.9 from 466 reviews on this ASIN
- Nylon named, at 210 g, with no drilling stated
- Several reviewers fitted it on outward-opening windows
- The tape is described as removable when the weather cools
Cons
- Adhesive fails in heat, from a few days to about six weeks
- Window type, dual hose, and dryer are not stated
- A pictured casement did not match an inward-opening window for one reviewer
- Closure is a drawstring, while one review mentions a broken zip
Best for: You have an outward-opening window under 300 cm and you want a drawstring cloth you can take down.
Less suitable: You need a named window type, a dual zip, or tape that has held through a heatwave in the reviews.
Specifications
- Model
- VOLIKRA 300 cm window seal
- Brand
- VOLIKRA
- Price
- ∼£16
- Customer rating
- 3.9/5(466)
- Length
- 300 cm
- Hose closure
- Drawstring
- Drilling
- No
- Material
- Nylon
Common questions
How does the VOLIKRA seal close on the hose?
The bullets say you stick the tape, press the fabric on, and tighten a drawstring. They do not describe a dual zip.
Does it fit an outward-opening window?
Several reviewers say it fitted outward-opening windows. Another says the picture's standard UK casement claim was wrong for an inward-opening window.
How long does the tape last?
Reviewers report the adhesive failing in the heat, from a few days to about six weeks, and having to add more tape.
Our view
The BTSAE TAW0437 is a cuttable 114 × 113 cm sheet at £7.99 and 420 g, claimed as 600D Oxford with a TPU coating, and amazon.co.uk shows 2.0 from 18 reviews. The bullets say you can cut it for openings from about 62.7 × 87.7 cm up to 107.7 × 127.7 cm, including narrow or round windows, if it sits flat on all four sides, with a drawstring for a hose up to 15 cm and an insect mesh. Most of the 17 review texts in the file say the double-sided tape sticks to the frame and not to the fabric, and that the hose pulls the sheet down within minutes. Reviewers describe thin plastic, stitching faults, and a zipper with no slider. One person saw yellowing after about two weeks and replaced the sheet with Perspex. A minority report says the tape held through several hot days, or that wider hook-and-loop kept it up. At this star line it is the row to skip if the sheet has to stay up while the unit runs.
Pros
- Cut range stated, from about 62.7 × 87.7 cm to 107.7 × 127.7 cm
- Drawstring for a hose up to 15 cm
- Insect mesh listed for when the unit is off
- No drilling stated
Cons
- 2.0 from 18 reviews, with 17 texts in the file
- Tape sticks to the frame and not to the fabric in most of those texts
- The hose pulls the sheet down
- Reviewers report thin material, stitching faults, and yellowing
Best for: You want a flat sheet you can cut, and you already plan to replace the included tape.
Less suitable: You need the seal to stay up on the tape in the box while the air conditioner runs.
Specifications
- Model
- BTSAE cuttable casement sheet
- Brand
- BTSAE
- Price
- ∼£8
- Customer rating
- 2.0/5(18)
- Window types
- Casement, if flat
- Length
- 114 × 113 cm
- Hose closure
- Drawstring
- Drilling
- No
- Material
- 600D Oxford, TPU
Common questions
Can you cut the BTSAE sheet to the window?
The listing says you can cut it for openings from about 62.7 × 87.7 cm up to 107.7 × 127.7 cm, including narrow or round windows, if it can sit flat on all four sides.
Does the tape hold the sheet?
The listing claims strong double-sided tape. Most of the 17 review texts say the tape sticks to the frame and not to the fabric, and that the hose pulls the sheet down.
Is there a mesh?
The bullets include an insect mesh for ventilation when the air conditioner is off. The hose opening is a drawstring for ducts up to 15 cm.
How we compared
Scores use the twelve amazon.co.uk listings in this comparison, the prices and star lines in those files, and the review notes stored with them. This is not a laboratory test. A star rating is not a measurement of how much heat the cloth stops, and a watt, volt, or decibel field on a cloth listing is a template row, not a specification of the seal.
1
Window and kit fit
35%The largest share looks for a named window, a sliding-window exclusion, a stated length, the closure, a dual hose or dryer line, a named fibre, and no drilling. A vague claim of most UK windows scores below a casement, tilt, or side-hung sentence.
2
Amazon evidence
25%Stars are read from the amazon.co.uk line on that ASIN, with a small uplift for a larger review file. When the same star line and the same review text are shared with another ASIN in this set, that block is reduced. The score is capped.
3
Review notes
20%An own file with a use and a limit, and no dominant failure, ranks above a shared file. Adhesive that splits, a zip that still leaks, zips that do not lock, and tape that will not hold the sheet are marked down from the review notes.
4
Price credibility
20%The best value is the highest price-credibility score on a different ASIN from the top pick. A mid-price kit with its own review file and named windows scores above a short cloth at the top of the set, or a shared star line at a higher price.
Independent review
Last updated: 20 October 2026
8 sources checked
Air conditioner window seal buying guide
Match the window first, then the length, then the closure. The shelf price does not tell you whether the tape will stay up in a warm room.
What is an air conditioner window seal?
An air conditioner window seal is the fabric kit that closes a UK casement or tilt window around the exhaust hose of a portable air conditioner, and often a vented tumble dryer, without drilling. You are usually replacing the plastic slider that came with the unit, because that bar suits a sash or horizontal slider and fights a hinged window. A vertical sash wants that slider bar, not this fabric strip. The listings in this set are for side-hung, top-hung, and tilt windows.
Best for
- Renters who need a hose out of a casement without drilling, and who can remove the tape later
- Owners whose supplied slider does not fit a hinged window and who want a seasonal kit
Not ideal for
- Sash windows, sliding windows, and patio doors
- Anyone treating a shared 4,220 or 101 as a separate test of each length
Mistakes to avoid
- 1
Trusting a universal claim
These listings are for side-hung, top-hung, and tilt windows. They are not for sliding windows or patio doors. A vertical sash wants the slider bar from the air conditioner. A pictured casement is not proof the cloth fits an inward-opening window.
- 2
Adding four sides
One Machine-YA reviewer says the diagram adds four sides but the seal covers three and you skip the hinge. Too short leaves a gap. Too long looks baggy but can still work. Measure the sides you will actually cover.
- 3
Counting a shared star line twice
Three MOEGFY ASINs share 4.0 from 4,220 and the same review text. Both OWYR lengths share 4.1 from 101 and the same text. Comments that name 400 cm are not a test of a 300 cm cloth.
What to weigh up
Window type and length
HighStart with the window, because the wrong cloth will not become a sash bar. These listings are for side-hung, top-hung, and tilt windows, and the ones that are explicit say they are not for sliding windows or patio doors. A vertical sash wants the plastic slider that came with the portable unit. 300 cm and 400 cm are the two strip lengths in this set. One Machine-YA reviewer says the diagram adds four sides but the seal covers three and you skip the hinge. Too short leaves a gap.
Closure and adhesive
HighA double-ended zip suits one hose or two. A drawstring, on VOLIKRA and BTSAE, is a different opening. Expect a small gap at the zip. Listings admit it. No kit here asks you to drill. The adhesive is the main failure in the review notes: it lets go in heat, will not stick to the fabric, or leaves glue. In a rental, test a corner and assume you may need residue remover. Useful materials in the tables are 210T polyester with a PU coating, nylon, or a stated Oxford cloth.
Which option suits you?
Three typical situations, each with a recommendation from this comparison.
Three sides within 300 cm
Your open sides, skipping the hinge, are within 300 cm and you want a kit that names the window and excludes sliders. This is the lower price in the set with a large own review file.
Casement, possibly two hoses
The supplied slider does not fit a hinged window, and you may have a single-hose or dual-hose unit, or a dryer hose. Measure the sides before you order. A cut panel is a different product.
Common questions about air conditioner window seals
Which air conditioner window seal is the top pick?
The DREO DR-HPA039 400 cm kit is the top pick. It scores 73 on the method for this page: casement stated, sliding windows excluded, a single or dual hose stated, and a tumble dryer or dehumidifier hose stated, with no drilling. amazon.co.uk shows 4.2 from 85 reviews on this listing, not a shared parent count. One reviewer reported a tear almost immediately, and the 4 m × 4 m size line does not describe a 400 cm strip, so measure the sides you will cover. It costs about £19.99.
How much does an air conditioner window seal cost?
On the amazon.co.uk listings in this comparison, dated 19 October 2026, prices run from about £7.99 for the BTSAE cuttable sheet to about £29.99 for the MOEGFY 300 cm kit. Most zip kits sit around £16 to £23: Machine-YA about £16.38, LYUNIT about £16.99, Derwit about £17.99, DREO and EGNBU about £19.99, and the MOEGFY 400 cm rows about £21.99 and £22.89. OWYR is about £25.99 for both lengths. A higher price here is not a different fixing method.
Will these kits fit a sliding window?
No. The listings that name a window are for side-hung, top-hung, tilt, or casement windows, and several say they are not for sliding windows or patio doors. A vertical sash wants the plastic slider bar supplied with the air conditioner, not this fabric strip. Derwit, EGNBU, LYUNIT, VOLIKRA, and the newer MOEGFY 400 cm row do not all print a sliding exclusion, so do not infer one. If your window is a slider, this set is the wrong product.
How long a seal do I need?
300 cm and 400 cm are the two strip lengths here. Measure the sides you will cover. One Machine-YA reviewer says the diagram adds four sides but the seal covers three and you skip the hinge. Too short leaves a gap. Too long looks baggy but can still work. The BTSAE sheet is about 114 × 113 cm and is cut down, which is a different shape from a perimeter strip. The DREO size line that prints 4 m × 4 m does not describe a 400 cm strip.
Are the 4,220 MOEGFY reviews three separate tests?
No. Three MOEGFY ASINs share 4.0 from 4,220 and the same review text. Comments in that text that name 400 cm are not a test of the 300 cm cloth. Both OWYR lengths share 4.1 from 101 and the same text, so that is one pool, not two. Machine-YA, EGNBU, LYUNIT, Derwit, DREO, VOLIKRA, and BTSAE show counts on their own listings. A star average is not a measurement of how much heat the cloth stops.
Can I use a seal in a rented flat?
These kits say no drilling, which is why renters look at them. The adhesive is also the main failure: it lets go in heat, will not stick to the fabric, or leaves glue. Test a corner, and assume you may need residue remover. Listed frames and strict leases: ask before a summer of adhesive. A fabric sheet is not a lock. On an accessible ground-floor window, take it down when you go out. The portable unit itself is a separate choice, covered in mobile air conditioning units.
Is a fabric kit as tight as a cut panel?
No. A fabric kit reduces the hole around the hose and still leaks at the zip and the edges. A cut acrylic, polycarbonate, or foam-board panel seals more tightly if you can measure the opening. That panel is a different product from the twelve kits here. We do not claim a measured electricity saving, or that any kit is as efficient as a split system. Call a professional for a split system, a wall sleeve, screws into a listed sash, or a unit that leaks onto electrics.
Do I need to drill?
No kit in this set asks you to drill. You stick hook tape, press the cloth on, and close a zip or a drawstring around the hose. The listing still allows a small gap at the zip. Wattage, voltage, and SEER fields on several pages are template rows from an air-conditioner form, not a specification of the cloth. The seal has no BS 1363 plug and it is not an F-gas appliance.
Our verdict
The top pick is the DREO 400 cm window seal. It is the only row that states a casement, excludes sliding windows, and names a single or dual hose plus a dryer, with 4.2 from 85 reviews on that listing. The best value is the Machine-YA 300 cm seal at about £16.38, with 4.0 from 817 reviews on its own file, if 300 cm covers three sides and you can live with zips that do not lock. A higher price in this set is not a tighter fixing method, and a shared 4,220 or 101 is one pool, not a separate test of each length.
Best value
View offer
Machine-YA 300 cm window seal
Highest price-credibility score on a different ASIN: about £16.38, windows named, sliders excluded, own file of 817.
Editorial
Editor
Home coolingamazon.co.uk listingsWindow seals
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Updated: 20 October 2026
8 sources checked
Guides to air conditioner window seals
Guides on what to look for, how to use a product, and common mistakes.
Window seal buying guideWindow type, length, and fixing, without the product table.Best window sealWho each strong listing is for, and who should skip it.How to fit a window sealClean the frame, stick the tape, zip the hose, and recheck in heat.Casement windowsOutward and tilt casements. Sash and sliders stay off that page.Fabric kit or rigid panelZip cloth against a cut panel. The panel is not a thirteenth ASIN.
Related comparisons
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.
- NHS: heatwave, how to cope in hot weather (retrieved 19 October 2026)
- GOV.UK: beat the heat, keep cool at home (retrieved 19 October 2026)
- Consumer Rights Act 2015, section 9 (retrieved 19 October 2026)
- GOV.UK: product safety advice for businesses (retrieved 19 October 2026)
- GOV.UK: reporting product safety issues (retrieved 19 October 2026)
- Aircon Revolution: window seal kits for portable air conditioners (retrieved 19 October 2026)
- Ideal Home: portable air conditioner window kits (retrieved 19 October 2026)
- Appliances Direct: how to install home air conditioning (retrieved 19 October 2026)
Expert source (DIY & tools): Charlie White (Charlie DIYte) (external profile) – public expert commentary used as a research source, not as a contributor to our pages.
This page contains affiliate links to amazon.co.uk. If you buy through them, we may earn a commission at no extra cost to you. Prices and star ratings are the shelf figures from those listings. We did not run a lab test.