Caleffi and the Carolyn House in London

Carolyn House, London

Housing estate


Altecnic Ltd - CALEFFI group


A new apartment block in London has been converted from offices will benefit from an energy efficient district heating system thanks to Caleffi manufactured Heat Interface Units (HIUs) and more than 800 dynamic thermostatic valves (TRVs), thanks to Altecnic support, our Caleffi group partner operating in UK and Ireland. 16 storey building was converted to retail space on the ground and part first floors and residential accommodation to the second.

[Credits JJ Rhatigan: Carolyn House London about the project]



Achieving maximum efficiency from such a system relies on the HIU in each apartment returning a very low temperature back onto the network. This keeps primary flow rates low, reduces heat lost from the system, ensures the greatest benefit from any included renewable energy sources and allows condensing boilers to work at their optimum efficiency. 

The low heating demand in modern apartment means that only a very small flow rate of hot water is required on the space heating circuit. This low flow rate makes it difficult to balance the radiators, so there is a danger of a high space heating return temperature being passed back onto the netwrok. This reduces the efficiency of the whole netwrok.

The soulution to avoid this all was to install DYNAMICAL® TRVs to ensure that the required flow is never exceeded, and to install the SATK32103 HIUs yo enure that the pre-set primary return temperature is met.

Download the Carolyn House Case