Best Portable Air Conditioners UK 2026: The Complete Buyer's Guide

How to choose a portable air conditioner

A portable air conditioner is a self-contained refrigeration unit on castors that cools a single room and vents hot exhaust air outside through a window. Before you compare models, get these five things right.

1. BTU — match the cooling power to the room

BTU/hr (British Thermal Units per hour) measures cooling capacity. Undersize it and the unit runs flat-out yet never cools; oversize it and you waste money and get clammy, under-dehumidified air. As a rule of thumb for a standard UK room with average insulation and ceiling height, allow roughly 20–25 BTU per square foot:

Room size	Typical use	Recommended BTU
Up to 14 m² (150 sq ft)	Small bedroom, study	5,000–7,000 BTU
14–20 m² (150–215 sq ft)	Double bedroom, home office	9,000 BTU
20–28 m² (215–300 sq ft)	Living room	10,000–12,000 BTU
28 m²+ (300 sq ft+)	Open-plan, kitchen-diner	12,000–14,000 BTU

Add roughly 10% for a south-facing or top-floor room, another 10% for large windows, and around 600 BTU per person if the room is regularly busy. South-facing loft conversions are the classic case for sizing up. Not sure? Use the BTU calculator to size it properly before you buy.

2. Noise — the number that matters in a bedroom

Noise is quoted in decibels (dB(A)). Portable units sit in the 50–65 dB range because the noisy compressor lives inside the unit (unlike a wall-mounted split, where it's outside). For a bedroom, aim for under 54 dB on the lowest/sleep setting. Anything quoted at 65 dB is fine for a living room with the TV on but disruptive overnight. Look for a dedicated "sleep" or "night" mode that dims the display and steps the fan down.

3. Modes — cool, fan, dehumidify, and heat

Most units offer cooling, fan-only, and dehumidifying modes. A dehumidify-only mode is genuinely useful on muggy-but-not-hot British days, though a standalone dehumidifier is more efficient if damp is your main concern. The premium option is a heat-pump (reversible) model that also warms the room in shoulder seasons — effectively a year-round appliance.

4. WiFi and smart control

WiFi app control and Alexa/Google compatibility let you pre-cool a bedroom before bed or switch off remotely. It's a convenience, not a necessity — but on a 24-hour timer it can trim running costs by avoiding cooling an empty room.

5. Running cost — the honest numbers

A portable AC draws roughly 0.8–1.3 kWh per hour. Under the Ofgem price cap for 1 July–30 September 2026 of about 26.1p per kWh (average direct-debit electricity rate), that's roughly 21p–34p per hour at full tilt. In practice the compressor cycles off once the room hits temperature, so real-world costs typically run 20–40% lower.

Unit size	Power draw	Cost/hour (≈26.1p/kWh)	4 hrs/day, 60-day summer
7,000 BTU	~0.8 kWh	~21p	~£50
9,000 BTU	~0.9 kWh	~24p	~£56
12,000 BTU	~1.2 kWh	~31p	~£75

The hoseless myth — read this before you buy

You'll see "portable air conditioners" advertised as hoseless or "no window needed". Be careful: a true air conditioner must expel heat somewhere, which means an exhaust hose to a window. The laws of thermodynamics don't bend for marketing.

What's actually being sold hoseless is almost always an evaporative cooler (or "air cooler") — a fan that blows air over a wet pad. These cool the air a few degrees by adding moisture, work only in dry heat, and actively raise humidity indoors, which makes a muggy UK heatwave feel worse. They're cheap to run and fine as a breeze, but they are not air conditioners. If a "hoseless AC" doesn't quote a BTU rating, it's an evaporative cooler. Genuine refrigerant-based portable air conditioners always need that hose.

Our picks by category

We recommend by type rather than chasing a single "winner", because the right unit depends on your room.

• Best overall — a 9,000–12,000 BTU unit with cooling, dehumidify and fan modes, a 24-hour timer and WiFi, sitting around 63 dB. Covers most UK living rooms and doubles as a dehumidifier in autumn. Brands like Meaco and EcoAir dominate here.
• Best quiet / bedroom — prioritise a sub-54 dB sleep mode over raw power. A 7,000–9,000 BTU unit with a night setting is ideal; Meaco is the benchmark for low-noise running.
• Best value — a no-frills 7,000–9,000 BTU unit from Pro Breeze, Igenix or Costway. You lose WiFi and the quietest acoustics but get genuine refrigerant cooling at the lowest outlay.
• Best for large rooms — 12,000–14,000 BTU for open-plan and kitchen-diners. Check the hose reaches your window and that there's a self-evaporation system so you're not emptying a tank constantly.
• Best heat-pump (year-round) — a reversible 4-in-1 unit that cools in summer and heats in spring/autumn. Costs more upfront but earns its place as an all-season appliance.

Browse the full range of portable air conditioners to match these specs to in-stock models, all with free UK delivery.

Portable vs fixed: when to upgrade

A portable unit needs no installation, no planning permission and no engineer — you unbox it, fit the window kit and switch on. A fixed split-system is quieter and more efficient, but in the UK it must be installed by an F-Gas certified engineer (it's illegal otherwise), typically costs £1,500–£3,000 per room, and — for a cooling-only outdoor unit — generally requires planning permission. (A reversible heat-pump condenser can fall under Permitted Development, but a cooling-only one does not.) For renters, flats, listed buildings and anyone wanting cooling this week, a portable unit is the sensible choice.