Heat batteries & heat pumps enable removal of gas in towers

Integrated system design allows the removal of gas combi boilers from 364 space-constraint homes – increasing tenant safety and reducing CO2-emissions.

When Gentoo Housing was faced with the dilemma of replacing old gas combi boilers without decanting residents from 364 apartments in a tower block, they turned to their energy services supplier Engie for advice. To complicate matters, it had been decided to remove gas supply to the building. Any new system would have to be easy to use and fit into the limited space available in each home, which ruled out introducing hot water tanks and the associated pipework they require.

The answer was an integrated system solution to replace the gas combi boilers with Sunamp’s super compact UniQ heat batteries and Kensa’s Shoebox Heat Pumps, the quietest and smallest ground source heat pumps available in the UK. The system is controlled by an easy to understand user interface. 

This integrated system, which is fed communally but managed locally allowing householders to shop around for the best electricity deal, occupies the same constrained space taken up by the redundant combi boiler. What’s more, residents are now enjoying improved hot water performance from a UniQ heat battery, and the comfort of heat generated efficiently at the point of use through their Kensa Shoebox Heat Pump.

Building safety has improved as there is no longer a danger of gas explosions, and the risk of CO poisoning and legionella disease has been eliminated. Maintenance costs are considerably reduced as there is no longer any need for annual gas safety tests and certification, or cylinder safety checks. Carbon emissions will be reduced by an estimated 420 tonnes, or nearly 70% per year.

The Sunamp / Kensa  partnership solution has enabled gas supply to be removed for the first time in an occupied high-rise building in the UK, with minimum disruption. The same system can equally be applied and bring the same advantages to lower density housing. 

Technical details:

Carbon savings: Approx. 420t/yr (-70%)

Heating capacity: 308 x 3 kW + 56 x 6 kW (1.26 MW)

Storage capacity: 364 x 9 kWh (3.28 MWh) 

Heating source: Individual heat pumps (Kensa Shoebox) and heat batteries (Sunamp UniQ) connected to an open-loop ground-source system.

Heat Pump Supply Temperature: Space Heating up to 55°C and Heat Battery charging up to 65°C.