The Short Answer: No, They Don’t
Do your water cooled air conditioning systems use a lot of water is a question we are asked all the time.
Cool You’s water-cooled air conditioning systems use water—but not a lot. They are carefully engineered for London flats and apartments, where external condensers aren’t allowed.
These systems are fully internal and designed with efficiency in mind.
Smarter Cooling, Smarter Water Use
Cool You’s fully internal, water-cooled air conditioning systems are far more sophisticated than many others on the market. Designed exclusively for London apartments and homes, our systems strike the perfect balance between powerful performance and efficient water use.
We don’t rely on basic open-shut water valves like many other systems available in London. Instead, each Cool You system is fitted with a high-precision 3000-stage water control valve. This continuously adjusts the water flow based on cooling demand — maximising efficiency every second the system is running.
The need for air conditioning in flats and apartments in London is increasing as the city experiences warmer temperatures throughout the year. Environmental efficiency and cost-effectiveness are significant concerns for those considering internal air conditioning systems.
In light of this, our managing director, Savva, an expert in air conditioning for flats, provides valuable insights into a commonly asked question: Do Your Water Cooled Air Conditioning Systems Use A Lot Of Water?
At Cool You, we recognise the importance of minimising water wastage. We discuss various water options with our customers during our free, no-obligation site survey.
How Much Water Does Cool You Air Conditioning Use?
Cool You’s water-cooled air conditioning systems use water — but they use it intelligently.
In fact, they are designed specifically for London homes and apartments, where access to external units and drainage is restricted.
Our air conditioning system only uses water when the AC is in operation, and the water connection is to the condenser itself. The condenser opens a water valve in the system that allows controlled water flow when it becomes too hot and needs to dissipate heat. This is the water that runs to waste. (If you want to boost efficiency further, that heat-laden water can be diverted to a hot water cylinder, reducing energy use elsewhere in your home).
We have installed over a thousand Cool You systems in London flats and apartments, and customers rarely voice concerns about water usage or running costs. This demonstrates the efficiency of our systems.
It is worth noting that conventional air conditioning systems use 100% electricity, while our fully internal system uses less electricity and a small proportion of water. However, the overall cost of our system is the same as that of other conventional systems.
So, Is It Wasteful?
Not at all.
The water used is minimal and carefully controlled. Our systems are built for homes where both space and environmental impact matter.
Some of our clients opt for the hot water recycling option to maximise efficiency. It's an excellent way to improve energy performance, especially in eco-conscious households.
Real-World Usage Examples
Water consumption depends on three main factors:
- Setpoint Temperature: Lower target temperatures use more water. Keeping your room at 18°C will naturally consume more water than maintaining 22°C. (See our article about the best way to run an ac system)
- Outdoor Temperature: The hotter it is outside, the harder the system needs to work — and the more water it will use to extract the extra heat.
- Building Type: Homes with large glass surfaces or poor insulation need more active cooling, which can increase water demand.
Example:
Cooling a well-insulated modern bedroom (5m x 4m) with a 2kW unit on a warm 27°C day might use approximately 60 litres of water per hour during peak operation.
But here’s the key: once the room hits your desired temperature, the system backs off. The advanced controls reduce water use dramatically as the unit cycles gently to maintain comfort — not constantly push toward it.
Water Use vs Comfort: Your Choice
The cooler you want the room — or the hotter it is outside — the more water the system will use. But the choice is yours. Thanks to our smart controls, you get a responsive, tailored cooling experience that adapts to your lifestyle.
And unlike noisy, bulky external units or cheap, inefficient portable options, Cool You gives you quiet, invisible comfort with no compromise on performance or aesthetics.
Designed for London Living
Cool You's systems are made exclusively for London homes — especially apartments where external condensers are not permitted. Every unit is fully internal, beautifully discreet, and designed to integrate seamlessly with high-end interiors.
And with R32 refrigerant, our systems deliver strong cooling power with a lower environmental impact.
In Summary: What Sets Cool You Apart
- Advanced 3000-stage water control valve for continuously optimised efficiency
- Smart, low water use — only what’s needed, when it’s needed
- Optional hot water recovery for extra eco-value
- Designed and built exclusively for London homes and apartments
- iFeel temperature control - pinpoint-accurate air conditioning in an exact location
- Installed by our fully internal, dedicated team — usually in just one day
Trusted by London’s Finest Homes
With over a decade of experience, Cool You has installed systems in thousands of high-end homes across London—from period apartments in Kensington to modern towers in Canary Wharf.
We consistently earn 5-star reviews on Trustpilot, thanks to our reliable performance and attentive customer care.
Ready for Cool, Calm, London Living? Speak to Our Experts
Please let us know if you have any further questions or concerns regarding the water usage of our fully internal AC systems. Got more questions? We're here to help. Contact Cool You on 0207 043 2275 or fill out our form below, and we will gladly assist you.
Let’s talk about a smarter way to stay comfortable — one that works beautifully, efficiently, and invisibly in your home.