A new approach to domestic heating is gaining attention by repurposing small-scale data servers to reduce household energy costs while addressing environmental concerns linked to large data centers. In London, Giles Gibson’s home benefits from a compact computer server attached directly to his hot water cylinder, which generates heat during operation and transfers it to warm the water, lowering reliance on traditional gas heating.
The system, developed and supplied by Surrey-based company heata, leverages the natural heat produced by processing tasks on home-installed servers. Unlike conventional data centers that often waste significant amounts of heat, this model recycles the thermal energy within domestic settings. Gibson, whose four-bedroom house has had the system installed since last year, estimates a monthly saving of £10 to £15 on hot water bills, providing a modest but consistent reduction in household expenses.
Heata’s commercial director, Charlie Beharrell, explained that the company’s servers operate with a power equivalent to about eight laptops. The system is designed to cover roughly 80% of a home’s hot water heating needs, with conventional boilers supplementing during peak demand, such as bath time. The server units attach to vented, unpressurized water cylinders—typically identifiable by blue insulation—using thermal paste to conduct heat without additional plumbing. Installation is free and lasts a few hours, with heata covering the electricity cost of the server, while homeowners provide fiber broadband connectivity to support the server’s operation.
Although the technology is currently incompatible with homes using combination boilers, an adaptation for unvented cylinders is under development. Heata has installed its heat-recycling servers in about 100 homes, with thousands more on a waiting list, and anticipates expanded deployment next year.
Separately, a different model is being trialed in Essex, where two households use large arrays of miniature computers clustered in freezer-sized units known as HeatHub, manufactured by Wales-based thermify. These units also capture and repurpose server heat but operate on a different technical basis from heata’s setup.
This innovation emerges amid growing concerns over escalating domestic energy bills and the environmental footprint of expansive data centers, which consume substantial electricity and release excess heat. Industry and local governments are pursuing various solutions to reduce heat waste and improve energy efficiency.
Among other innovations, the British clean technology firm tepeo has developed a zero-emission boiler that stores heat during low-cost electricity periods and releases it on demand, optimizing energy consumption through smart charging. In Scotland, Midlothian Council and Vattenfall have created a low-carbon heat network in Shawfair Town and Craighall Village by utilizing surplus thermal energy from a nearby waste recycling and energy recovery plant.
Further initiatives include Underheat’s Energy Wall, which integrates pipe systems into insulation panels to improve heat pump efficiency and reduce condensation-related issues, and Kestrix, which uses drone mapping to identify and address heat loss across urban neighborhoods.
Together, these technologies and projects illustrate a growing trend to repurpose waste heat and adopt smarter, more sustainable methods for domestic heating, aiming to lower costs and reduce environmental impact.