The best 12000 BTU air conditioners, compared.
Top pick: Generic 12000 BTU wall split Best value: Air Pro AP-E4 12000 BTU – Best price against a complete monobloc spec and a review set you can read: R290, 26 kg, 1,025 W, class A and a window kit, at about £499.99. Updated 20 October 2026.
A 12,000 BTU air conditioner removes about 3.5 kW of heat per hour. UK retailers treat that as a living-room or large-bedroom size, not a whole flat. You are choosing a portable monobloc with a window hose, a portable split whose compressor sits outside, or a fixed wall split that needs an installer. Quality shows up as a stated refrigerant, a weight around the mid-20s of kilograms or more for a monobloc, a window kit that fits your window, and a noise figure you can decode. The words 4-in-1 do not replace those fields. Evaporative water-tank coolers, and listings of a few kilograms and a few tens of watts, are not this product, even when the title prints 12,000 BTU. A smaller bedroom is often closer to a [9,000 BTU air conditioner](/hub/cooling/9000-btu-air-conditioner). The useful choice is the architecture, not the BTU in the title. A single-hose monobloc dumps room air outside and pulls warm air back in through gaps. Measure length times width before you trust a coverage line.
A 12,000 BTU air conditioner removes about 3.5 kW of heat per hour. UK retailers treat that as a living-room or large-bedroom size, not a whole flat.
22 products checked · 58 hrs invested · +19,200 readers
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Personal buying guide
Question 1 of 2
Can you fit a fixed outdoor unit?
The generic wall split at £659.99 is a 12,000 BTU R32 heat pump that the listing says needs an outdoor unit, and the two written reviews say it works once an engineer has finished the job. The star line is 5.0 from 3 ratings, which is too small a sample to treat as a quality ranking against the Midea’s 23 reviews or the Air Pro’s 20. One of those reviews says parts were missing and the seller sent them within 48 hours before the engineer visit, so the £659.99 is hardware, not a fitted system. The efficiency line says A++ and SEER 6.2, while a bullet says A+++, and the weight field is 10 kg for a package that claims to include both indoor and outdoor units. Voltage is printed as 220 V, and the plug type is not stated. The noise field is 23 dB, with no test method on the listing, so that figure is not a bedroom measurement from this comparison. Buy the hardware only if you already have an F-gas qualified installer and you will check the parts list on arrival.
Pros
Cons
Best for: You have an installer booked and you are buying the hardware, not a turnkey fit.
Less suitable: You wanted a window-kit portable, or you are choosing by five stars alone.
Specifications
Common questions
Is an outdoor unit part of this purchase?
Yes. The specification says an outdoor unit is required, and included components list an outdoor unit, an indoor unit, a drain hose, and pre-gassed. The form factor is split system.
Which energy rating does the listing print?
The efficiency line says A++ and SEER 6.2. A bullet says A+++. Both appear on the same amazon.co.uk listing, so the page does not settle on one class.
What did the UK reviews mention about delivery?
There are 3 ratings at 5.0 and two review texts. One says missing parts were sent within 48 hours before an engineer visit. The other praises delivery. The price does not include that engineer.
The XIUNYIE PSH-HL5YNEOQ is a 12,000 BTU portable at £456.24 with a single amazon.co.uk review at 5.0, and that review says it cooled a lounge quickly. The box list is concrete: unit, remote, flexible hose, window vent kit, adapters and a user guide, and a bullet claims a UK 3-pin plug described as BS 1363. Noise is listed at 50 dB, the claimed area is up to 300 square feet, and the thermostat bullet runs from 16 °C to 32 °C, with auto-evaporation plus an optional continuous drain. Voltage, wattage, refrigerant, energy class, weight and dimensions are all missing from the specification lines, so you cannot compare its running cost with the Air Pro’s 1,025 W and 26 kg. There is no second review to show whether leaks, hose length or noise repeat. At this price it sits next to units that do publish those fields, which is why a lone five-star line is not a reason to rank it above them.
Pros
Cons
Best for: You accept a thin spec and will check the plug and the hose length when the carton arrives.
Less suitable: You want a named refrigerant, a kilogram weight and more than one UK review before you pay £456.24.
Specifications
Common questions
What comes in the box?
The listing includes the unit, a remote control, a flexible hose, a window vent kit, adapters, and a user guide. An outdoor unit is not required.
Does the listing claim a UK plug?
A bullet says it comes with a UK 3-pin plug described as BS 1363. Voltage and wattage are not on the specification lines.
How many reviews are there?
The listing shows 5.0 from 1 review. That review says the unit cooled a lounge and that the seller offered another finish when white was out of stock. There is no second review to compare.
The Midea PortaSplit is a 12,000 BTU portable split at £1,099.99, rated 4.3 from 23 amazon.co.uk reviews, and reviewers who had used a single-hose unit say the lounge cools better because the heat leaves the room. Once the set temperature is reached, several of those reviews call the indoor section quiet, and the listing’s silent-mode figure is 39 dB(A) at 1 m under JIS C9612, which is not the same number as full cooling. Heating is listed as a heat pump, with A++ for cooling and A+ for heating in the bullets, at a stated 3.5 kW. The specification line says no outdoor unit is required, yet reviews describe a separate outdoor section, a connecting hose, and stacking the two parts, and one reviewer says the parts cannot be separated. At 45.5 kg and 34 × 51.8 × 64.6 cm it is a large footprint for a small room, and review prices sit around £950 to £1,000 as well as the £1,099.99 in this capture. A remote arrived dead for one buyer, and one review says some app features need a third-party subscription cited at £39.99. In this set it is the top pick when you can give that outdoor section a place and you are not wheeling it between floors every day.
Pros
Cons
Best for: You can site the outdoor section by a window and want the heat rejected outside the room without a fitted wall split.
Less suitable: You need to carry it upstairs every day, or £1,100 is the wrong budget.
Specifications
Common questions
Does the Midea listing include heating?
Yes. Special features include heating and cooling, and a bullet gives A+ for heating beside A++ for cooling. The cooling power line is 12000 BTU, with 3.5 kW in the bullets.
What noise figure is printed?
The specification noise field is 39 dB. A bullet says 39 dB(A) in silent mode, measured at 1 m distance and 1 m height to JIS C9612. That is the listing’s figure, not a bedroom test from this comparison.
Does the specification say an outdoor unit is required?
The specification line says no. Reviews on the same listing describe a separate heat-pump section, a connecting hose, and stacking the sections. Included components on the spec line are only the user manual.
The Air Pro AP-E4 is a 12,000 BTU portable monobloc at £499.99, 3.8 from 20 amazon.co.uk reviews, and buyers who used it in a heatwave say it can make a medium room very cold. The listing states R290, class A, 1,025 W, 26 kg, a window kit and a maximum window opening of 125.5 cm, with a claimed floor area of 30 m². The noise field is 65 dB, and several reviews say it is too loud for sleep or for watching television, including a bang when the compressor stops at the set temperature. Water leaking from the case and from seals is a repeated fault in the written reviews, not a normal tank empty, and one buyer found the supplied hose too short. Support is a weak point in the reviews: a swing fault went unanswered, a return after use was refused unless the buyer paid shipping, and one review describes a unit that behaved like a fan with Chinese-only material. It is the best value in this comparison when you want a specified hose portable with a real review set and you can live with the noise.
Pros
Cons
Best for: You want a hose portable with refrigerant, weight and wattage on the page, and you will not sleep next to it.
Less suitable: A bedroom overnight, or a window layout that needs a longer hose than the one in the box.
Specifications
Common questions
Does this Air Pro need an outdoor unit?
No. The listing says an outdoor unit is not required and that outdoor-unit compatibility needs no outdoor unit. It is a portable with a window kit.
What refrigerant and energy class are listed?
Refrigerant is R290. Efficiency is A. Wattage is 1025 W and voltage is 240 V. Annual energy consumption is printed as 1025 watts, which is the listing’s unit, not a converted yearly total.
What do the reviews repeat?
The listing is 3.8 from 20 reviews. Praise centres on cooling in hot weather and a hose kit that fitted. Repeated complaints are noise, leaks, a short hose, and weak support when something failed.
The QINLIGAO UQ4L8DE0 is listed at £319.99 as a 12,000 BTU portable with no outdoor unit, and the bullets still tell you to fit a 1.5 m exhaust hose and a window kit. There is no customer-review line on the listing, so cooling, night-time noise and leaks are untested on this page. The noise field is 52 dB, described in a bullet as a night mode, with a claimed room of up to 23 m² and a thermostat from 16 °C to 31 °C. Dehumidifying is claimed at up to 20 litres a day, and the modes are cool, fan and dehumidify, with no heating line. Refrigerant, wattage, weight, voltage and energy class are absent, which is the gap next to the Air Pro’s 26 kg and 1,025 W at a higher price. Four swivel casters and a remote do not replace that missing mass. Treat £319.99 as an incomplete listing until those fields appear, not as a saving on a known monobloc.
Pros
Cons
Best for: You will only consider it after the seller states refrigerant, wattage and weight.
Less suitable: You wanted a reviewed unit, or you read “no outdoor unit” as meaning no vent.
Specifications
Common questions
Does “without outdoor unit” mean it needs no vent?
No. The bullets say there is no outdoor unit or condenser, and they also say you connect a 1.5 m exhaust hose and a window venting kit. Both statements are on the listing.
What noise and room size are claimed?
The noise field is 52 dB. A bullet calls that a night mode and says the unit cools rooms up to 23 m², with a thermostat from 16 °C to 31 °C.
Is there a star rating?
No customer-review line is on the listing, so the rating is n/a. Refrigerant, wattage, weight and energy class are also n/a.
The generic listing at £498.92 labels the colour variant 12,000 BTU, while the title also names 14,000 and 18,000 BTU and a bullet says up to 18,000 BTU for rooms up to 30 m². Heating is in the title at 9,000 BTU, but the specification operating mode says cooling, so the heat-pump claim is not settled on the page. One line says an outdoor unit is not required, and the next says outdoor-unit compatibility requires a new outdoor unit, while a bullet talks about casters and no ductwork. There is no customer-review line, no noise figure, no refrigerant, no wattage and no weight. At £498.92 it costs about the same as the Air Pro, which does publish R290, 26 kg and 20 reviews. Keep it in the table as a listing whose own fields disagree, and do not use the 12,000 BTU colour label as proof of capacity.
Pros
Cons
Best for: You are using the comparison to see a page you should not shortlist.
Less suitable: You want one capacity, one installation type and a review you can read.
Specifications
Common questions
Which capacity does this listing claim?
The title says 12000/14000/18000 BTU and 9000 BTU heating. The colour is (12000btu). A bullet says up to 18000 BTU and rooms up to 30 m². There is no single cooling-power specification line.
Does it need an outdoor unit?
The listing contradicts itself. One line says an outdoor unit is not required. Another says outdoor-unit compatibility requires a new outdoor unit. A bullet talks about casters and no ductwork.
Are there customer reviews?
No customer-review line and no review text are on the listing. The rating is n/a.
Scores use the six amazon.co.uk listings in this comparison, shelf date 20 October 2026, and the review notes for the same ASINs. This is not a lab test. A claimed room size, a decibel field with no test method, or a five-star line from one or three reviews is not scored as a UK measurement. Weights sum to 100.
Amazon evidence
25%Star rating on amazon.co.uk, then a hard deduction when the count is under 20, and a harder one when there is no review line.
Listing fit
40%One capacity, a named refrigerant, wattage, weight, a coherent outdoor-unit line, and a vent method that matches the type. Contradictory BTU figures, a missing mass, or a 10 kg field on a complete wall-split pair score down.
Review outcome
25%UK reviews that describe cooling after a previous hose unit, or a fitted split that worked, score higher than a listing that repeats leaks, sleep noise, or unanswered faults.
Value
10%Shelf price in GBP against a specification you can compare. The lowest price does not win when refrigerant, wattage and weight are absent.
Choose the architecture first, then the room, then a refrigerant, a weight and a noise figure you can decode. The shelf price does not include an engineer, and a 12,000 BTU title is not a room survey.
A 12,000 BTU air conditioner removes about 3.5 kW of heat per hour. The useful choice is the architecture, not the BTU in the title. A single-hose monobloc dumps room air outside and pulls warm air back in through gaps. A portable split or a wall split rejects heat outside the room. Trusted Reviews explains the single-hose path. Measure length times width before you trust a coverage line.
Evaporative water-tank coolers, and listings of a few kilograms and a few tens of watts, are not a 12,000 BTU air conditioner, even when the title prints that figure.
Midea’s 39 dB(A) is silent-mode sound pressure at 1 m. The maker also lists 59 dB sound power. The Air Pro prints 65 dB. The wall split prints 23 dB with no test method. Those cells are not one scale.
Midea’s £13 season at £0.25/kWh and 136 hours is the seller’s scenario. A single hose in an open-plan room, or a 12,000 BTU title on a listing with no weight, is a separate mistake. Do not pierce an R290 circuit.
A single-hose monobloc dumps room air outside and pulls warm air back in through gaps. A portable split or a wall split rejects heat outside the room. A hose needs a window you can seal. A fixed outdoor unit in England is planning-sensitive: Class G permitted development does not cover cooling-only equipment. Scotland, Wales and Northern Ireland are separate. Pipework that you joint or charge is for an F-gas qualified person.
Measure length times width. AirConCompare’s rule of thumb puts about 28–35 m² in the 12,000–15,000 BTU band, and a 20 m² bedroom nearer 7,000–9,000 BTU. Lofts, south-facing glass and open-plan rooms need more. Separate sound pressure from sound power, and prefer a stated refrigerant, a weight you could not lift one-handed, and a BS 1363 plug on anything that draws around a kilowatt. Plan a drain or a tank.
Three typical situations, each with a recommendation from this comparison.
You may use a hose and a window seal, and you cannot fit a fixed condenser. The Air Pro AP-E4 states R290, 26 kg, 1,025 W, class A and a window kit, at 3.8 from 20 reviews. Several of those reviews say 65 dB is too loud for sleep.
You want the heat rejected outside the room without a drilled wall split. The Midea PortaSplit is the portable split in this set, at 4.3 from 23 reviews, with a heat pump and R32. Reviews describe a separate outdoor section even though the specification line says none is required.
Sort noise before capacity. A strong monobloc can still be unusable at night. The Air Pro reviews say it is too loud for sleep. Midea’s 39 dB(A) figure is silent mode at 1 m, not a bedroom measurement. The wall split’s 23 dB line has no test method on the listing.
On these amazon.co.uk listings the Midea PortaSplit is the top pick: a portable split with a heat pump, R32, 4.3 from 23 reviews, and a 39 dB silent-mode figure. The Air Pro AP-E4 is the best value at about £499.99, with R290, 26 kg, 1,025 W, class A, a window kit and 3.8 from 20 reviews. The generic wall split needs an installer, and 5.0 from three ratings is not a quality ranking. A single five-star review, or a listing whose capacity lines disagree, does not outrank a complete spec.
Air Pro AP-E4 12000 BTU
Best price against a complete monobloc spec and a review set you can read: R290, 26 kg, 1,025 W, class A and a window kit, at about £499.99.
Editorial
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.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources from the research digest. amazon.co.uk prices, stars and review counts are the listing lines for these six products, captured on 19 October 2026. This is not a laboratory test.
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 with the tag pcuk26-21. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are the UK listing lines for this comparison. We did not run a lab test.
