Energy recovery techniques : heat pumps

Heat pumps are systems composed of two heat exchangers and a heat-carrying liquid that can take up energy from a heat source (e.g. the ground, air washers or a biological reactor vessel) and release it into the building. The heat recovered can be used to heat sanitary water or to feed piped or forced-air spaced heating systems, as required.Setting up heat pumps on air washers is possible only if the building can store a large quantity of washing water. Given the environmental advantages of the technique and the 2.5- to 3-fold reduction in electricity consumption it achieves, this option is a useful lever of change that deserves support in future projects.