ABSTRACT
Wastewater in sewers contains heat energy which can be recovered and upgraded by using a heat pump. The upgraded heat could be used for space heating and hot water production. Two types of heat pump (an electric heat pump and a natural gas engine–driven heat pump) which can be used for sewer heat recovery are described. A method of estimating the potential useful heat that can be obtained by recovering the heat from the sewer is provided. Methods for estimating the heating capacities of the systems and the required power inputs are presented.
