A support assembly for a heat pump system comprising a base and a plurality of platforms for supporting a respective heat pump such as a thermoelectric cooler. Resiliently flexible pipes support the platforms with respect to the base and form part of a coolant circulation system. The platforms are movable with respect to each other and the support structures allow the platforms to move with respect to the base. An object to be cooled, such as an image sensor, is mounted on the heat pumps. The platforms are able to move in response to expansion and contraction of the object thereby preventing damage to the heat pump system.