Tonwell Tower, Hertfordshire

The transformation of a former water tower in the Hertfordshire countryside demonstrates how sustainability and comfort can go hand-in-hand.

With the help of Daikin’s high-performance HVAC systems, owners Matt and Ali Grey have turned the iconic structure of a former water tower into a luxurious, eco-friendly holiday home. The remarkable transformation of Tonwell Tower proves that even unconventional buildings can use heat pump technology to become models of sustainable, energy-efficient living.

“For us, it was about more than just restoring an old building. We wanted to create a home that’s efficient, comfortable, and respectful of the environment", says owner Matt. “We also wanted it to look fantastic.”

What challenges did the project present?

Originally built as a water tower, the structure presented unique challenges: it is 75 feet tall, circular, and designed to be self-contained. Daikin delivered an energy solution that would fit the space, cater to the comfort of its guests, and reduce environmental impact. 

Which Daikin systems were chosen?

By leveraging Daikin’s Air Source Heat Pump (ASHP) and Mechanical Ventilation with Heat Recovery (MVHR) systems, Tonwell Tower is now a year-round retreat that offers unparalleled comfort with minimal energy consumption.

What makes this an energy-efficient solution?

The ASHP system delivers an impressive 300-400% efficiency by extracting heat from the air and amplifying it to produce 3-4 kW of heat for every 1 kW of power consumed. This sustainable technology powers the underfloor heating, ensuring consistent warmth in every room without bulky radiators disrupting the sleek design. Additionally, the system meets the tower’s hot water needs, providing up to 300 litres of hot water at all times.

How is fresh air supplied to the sealed structure?

In Tonwell Tower, where windows remain closed to preserve the structure’s energy balance, the MVHR system maintains optimal indoor air quality while conserving heat. This advanced ventilation technology extracts stale air and introduces filtered, fresh air without losing warmth, recovering up to 81% of outgoing heat. A portable Daikin air purifier is also available to support removing allergens and bad odours if required. 

What key factors were considered in selecting the system?

The ASHP operates at 300-400% higher efficiency than a gas boiler. It is Quiet Mark certified, ensuring low noise levels. Users can control and monitor it remotely via the Onecta app, tracking energy use at no cost. Its sleek black fascia conceals the outdoor fan, complementing Tonwell Tower’s design. The system also supports future integration with solar panels for renewable energy.