Reverse Cycle (Heat Pump Mode)

A heat pump is not a different machine from the chillers this course has covered; it is the same vapour-compression cycle with its purpose reversed. Where a chiller's product is the cold side and the rejected heat is waste, a heat pump's product is the hot side and the cold is collected outdoors for free. Understanding this identity, and the reversing valve that lets one machine do both jobs, demystifies the technology now central to UK heat decarbonisation.