In-building waste water heat recovery: An urban-scale method for the characterisation of water streams and the assessment of energy savings and costs

摘要

Residential domestic hot water energy consumption represented 16% of the EU household heating demand in 2013. With the improvement of the building insulation envelope, domestic hot water contribution to energy consumption is expected to increase significantly, with values between 20% and 32% in single family buildings, and between 35% to almost 50% in multifamily buildings. This energy, currently lost to the environment, can be recovered by waste water heat recovery systems inside buildings (in building solutions). While most publications in this field focus on shower heat recovery and on waste water as heat source for heat pumps, the detailed impact of waste water heat recovery at a city scale by aggregating building data has not been addressed yet. Furthermore, waste water heat recovery potential and relevance was not yet quantified as a function of the specific inhabitant and household numbers, end-use occurrence, and building type and age.