Recovery of waste heat from the sewer system in the sanitary equipment of a sport complex

In the paper we introduced the possibilities of the recovery of waste heat from the sewer system as an answer to the minimalism of the demand of energy needed for the preparation of domestic hot water. The method of recovery of waste heat from the sewer system outside of the building is using a heat pump in combination of heat exchanger located in sewer system outside of the building - this systems are analyzed in the paper from the theoretical point of view. The recovery of waste heat from sewer system inside of the building is possible using heat exchangers in order to extract heat from waste water to direct preheating of cold water - this systems are analyzed from the theoretical point of view, are applied in the sanitary equipment of a sport complex and are evaluated from the energy and economical point of view. For both outdoor and indoor systems, there are several examples of heat exchangers currently used for recovering heat from waste water. The other part of the paper was dedicated to design of alternative solutions of the recovery of waste heat from the sewer system inside of the object of multifunction sport with application of heat exchangers to direct preheating of cold water in shower. The main point of this article was to introduce the possibilities of the recovery of waste heat from the sewer system, apply them in the object of multifunction sport complex and review the energy and economic efficiency and payback period of the heat exchanger.