Waste heat from the Tube warms homes in Islington

The centre uses state-of-the-art technology on the site of a disused City Road Underground station, transforming this to house a huge underground fan which extracts warm air from the Northern line tunnels below. The warm air is heated again using heat pumps to reach around 80°C and then pumped to buildings in the neighbourhood through a new 1.5 km network of underground pipes. 

In addition, the two-metre fan, installed in an existing six-storey London Underground mid-tunnel ventilation shaft, can also be reversed to help with cooling Tube tunnels in the summer.