10 Best Most Energy Efficient Window Air Conditioner in UK 2025
Updated on 23/06/2025
#1
Recommended
- 16,000BTU portable air conditioner and heater suitable for large rooms (30m² to 35m²)
- Class A energy efficiency with low noise operation (51.5dB) for a comfortable environment
- Includes remote control and digital display for easy temperature adjustments
- Standard and flexible window kits included for versatile installation
- Two-year warranty covering parts and labor from a reputable manufacturer
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- 16,000BTU portable air conditioner and heater suitable for large rooms (30m² to 35m²)
- Class A energy efficiency with low noise operation (51.5dB) for a comfortable environment
- Includes remote control and digital display for easy temperature adjustments
- Standard and flexible window kits included for versatile installation
- Two-year warranty covering parts and labor from a reputable manufacturer
#2
Value for Money
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- 9000 BTU cooling capacity provides effective cooling down to 16°C, suitable for medium to large spaces such as homes and offices.
- Wi-Fi connectivity allows for remote control of the AC unit via smartphone app or voice commands; compatible with Amazon Alexa and Google Home.
- Offers four functions: air cooling, dehumidifying, fan-only, and sleep modes, controllable through the app, digital display, or remote.
- Class A Energy Efficiency rating and R290 refrigerant make this unit an environmentally friendly choice that reduces energy costs.
- Includes two easy-to-install window venting kits for both slide and hinged windows, designed for minimal space intrusion.
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- 9000 BTU cooling capacity provides effective cooling down to 16°C, suitable for medium to large spaces such as homes and offices.
- Wi-Fi connectivity allows for remote control of the AC unit via smartphone app or voice commands; compatible with Amazon Alexa and Google Home.
- Offers four functions: air cooling, dehumidifying, fan-only, and sleep modes, controllable through the app, digital display, or remote.
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#3
15% Off
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- 4-in-1 functionality combines cooling, dehumidifying, fan, and sleep modes for year-round use with two adjustable fan speeds.
- Operates quietly at 52dB and uses eco-friendly R290 refrigerant, optimizing energy efficiency and reducing electricity costs.
- Equipped with an LED display and remote control for easy temperature adjustment (16-32℃), 24-hour timer programming, and a child lock for safety.
- Features ergonomic handles and 360° casters for easy mobility; includes a window kit for quick installation in various window types (17"-53").
- Modern design with ABS frosted plastic, user-friendly control panel, and strong airflow capacity (330m³/h) suitable for spaces up to 20㎡.
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- 4-in-1 functionality combines cooling, dehumidifying, fan, and sleep modes for year-round use with two adjustable fan speeds.
- Operates quietly at 52dB and uses eco-friendly R290 refrigerant, optimizing energy efficiency and reducing electricity costs.
- Equipped with an LED display and remote control for easy temperature adjustment (16-32℃), 24-hour timer programming, and a child lock for safety.
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#4
- Multiple air outlet options for customized cooling, including synchronized and multi-directional oscillation.
- 3 wind speeds and cooling modes, featuring a quiet sleep mode for peaceful nights.
- Rapid cooling with a honeycomb cascade system and ice crystal integration for efficient temperature reduction.
- Evaporative cooling lowers room temperature by up to 11°C and raises humidity by 82% to combat dryness.
- Bladeless design ensures safety for children and pets, with easy cleaning and no exposed blades.
- Energy-efficient, using no compressor or harmful refrigerants, with quick cooling features and easy maintenance.
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- Multiple air outlet options for customized cooling, including synchronized and multi-directional oscillation.
- 3 wind speeds and cooling modes, featuring a quiet sleep mode for peaceful nights.
- Rapid cooling with a honeycomb cascade system and ice crystal integration for efficient temperature reduction.
- Evaporative cooling lowers room temperature by up to 11°C and raises humidity by 82% to combat dryness.
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#5
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- Functions as an air cooler, tower fan, and humidifier, enhancing humidity levels in dry climates to prevent skin irritation.
- Designed for energy efficiency, consuming less electricity compared to traditional air conditioners.
- Utilizes a honeycomb waterfall filter and powerful motor for effective cooling, delivering airflow of 330m³/hour with three adjustable wind modes.
- Features three fan speeds and 60° oscillation for even airflow distribution, customizable to your comfort preferences.
- Equipped with a 7-hour timer for convenience and flexible remote control for easy operation from anywhere in the room.
- 5L water tank lasts up to 10 hours, with a detachable filter for easy cleaning and maintenance.
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- Functions as an air cooler, tower fan, and humidifier, enhancing humidity levels in dry climates to prevent skin irritation.
- Designed for energy efficiency, consuming less electricity compared to traditional air conditioners.
- Utilizes a honeycomb waterfall filter and powerful motor for effective cooling, delivering airflow of 330m³/hour with three adjustable wind modes.
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#6
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- Ultra-wide air outlet design allows for even cooling across a large area with a wind speed of up to 8m/s.
- Energy-efficient at 60W, this portable air conditioner covers up to 250 square feet, providing a cost-effective cooling solution without installation hassles.
- The 5.5L water tank provides up to 16 hours of cooling per fill, with a top-fill design for easy refilling and removable water curtain for simple maintenance.
- Features a 1-7 hour timer for auto shut-off and operates at a low noise level of 40dB, ensuring quiet comfort for sleep and relaxation.
- Equipped with an LED display and remote control, simplifying operation and allowing control from a distance of up to 10 meters.
- Compact and portable with built-in handle and 360° wheels for easy movement; can be stored in small spaces when not in use.
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- Ultra-wide air outlet design allows for even cooling across a large area with a wind speed of up to 8m/s.
- Energy-efficient at 60W, this portable air conditioner covers up to 250 square feet, providing a cost-effective cooling solution without installation hassles.
- The 5.5L water tank provides up to 16 hours of cooling per fill, with a top-fill design for easy refilling and removable water curtain for simple maintenance.
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#7
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- 4-in-1 functionality including cooling, dehumidifying, fan-only, and sleep settings with a quiet operation at 52dB.
- Remote control and LED display for easy adjustments of mode, speed, temperature (16-32°C), and a 24-hour timer.
- Portable design with four castor wheels and a dual window venting kit suitable for sliding and hinged windows, effective for rooms up to 18m².
- Class A energy efficiency rating with eco-friendly R290 refrigerant to maintain cooling performance affordably.
- VonHaus, established in 2009, focuses on innovative technology for year-round comfort.
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- 4-in-1 functionality including cooling, dehumidifying, fan-only, and sleep settings with a quiet operation at 52dB.
- Remote control and LED display for easy adjustments of mode, speed, temperature (16-32°C), and a 24-hour timer.
- Portable design with four castor wheels and a dual window venting kit suitable for sliding and hinged windows, effective for rooms up to 18m².
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#8
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- WiFi-enabled air conditioner can be controlled via smartphone through the Tuya Smart App, compatible with Alexa. Requires initial connection to 2.4GHz WiFi.
- Four operating modes: air conditioning, fan (with adjustable airflow), dehumidifier, and sleep mode for reduced noise and light during the night.
- Self-evaporating system enhances efficiency by using collected water to cool condenser coils, releasing vapor through the exhaust hose.
- Adjustable thermostat range of 16-32℃ for optimal comfort; includes a washable air filter for easy maintenance, recommended cleaning twice a month.
- Two window kits included for versatile installation: a flexible kit for sash windows and a secondary kit for various window types.
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- WiFi-enabled air conditioner can be controlled via smartphone through the Tuya Smart App, compatible with Alexa. Requires initial connection to 2.4GHz WiFi.
- Four operating modes: air conditioning, fan (with adjustable airflow), dehumidifier, and sleep mode for reduced noise and light during the night.
- Self-evaporating system enhances efficiency by using collected water to cool condenser coils, releasing vapor through the exhaust hose.
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#9
- Efficient cooling options include cooling, drying, and fan modes, delivering an airflow of 310 cubic meters per hour while reducing humidity for enhanced indoor comfort.
- Energy-efficient design with a Class A Energy Rating and environmentally friendly R290 refrigerant, ensuring lower power consumption and cost savings over time, backed by a two-year warranty.
- Portable and easy to maneuver with built-in castors, comes with a flexible window kit suitable for various window and door types, and features a child lock for added safety.
- Remote control via the Meaco app and digital display for monitoring temperature, plus a timer function that allows for pre-cooling a room between 1 and 24 hours to optimize electricity usage.
- Operates quietly with noise levels between 51-55 dB, featuring a Sleep Mode that minimizes sound and display brightness for peaceful nights and energy efficiency.
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- Efficient cooling options include cooling, drying, and fan modes, delivering an airflow of 310 cubic meters per hour while reducing humidity for enhanced indoor comfort.
- Energy-efficient design with a Class A Energy Rating and environmentally friendly R290 refrigerant, ensuring lower power consumption and cost savings over time, backed by a two-year warranty.
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#10
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- Cooling mode effectively lowers room temperature; Fan mode offers strong airflow; Dehumidification mode maintains humidity levels around 50%; Silent mode provides quiet operation.
- Compact design fits easily into various spaces, including living rooms and kitchens; Night sleep mode ensures low fan speed for quiet cooling while you rest.
- Versatile 4-in-1 unit functions as an air conditioner, ventilator, dehumidifier, and cooling system, enhancing air circulation and reducing indoor temperature quickly.
- Simple installation with a dual window kit; suitable for most window types, making it accessible for all users regardless of experience level.
- LED display shows current room temperature; Remote control functionality adds convenience for adjusting settings from a distance.
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- Cooling mode effectively lowers room temperature; Fan mode offers strong airflow; Dehumidification mode maintains humidity levels around 50%; Silent mode provides quiet operation.
- Compact design fits easily into various spaces, including living rooms and kitchens; Night sleep mode ensures low fan speed for quiet cooling while you rest.
- Versatile 4-in-1 unit functions as an air conditioner, ventilator, dehumidifier, and cooling system, enhancing air circulation and reducing indoor temperature quickly.
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