An ambient loop is essentially a communal low temperature heat network. It requires a centralized energy source, with heat being circulated via flow and return primary pipework at temperatures of say, 25˚ / 15˚ C. At each apartment / office, individual heat pumps are used to transfer the heat from the loop for hot water and space heating. DHW cylinder storage is required to satisfy instantaneous demand. Some manufacturers offer reverse operation of their heat pumps to provide cooling.