Impact of Wastewater Heat Recovery on the Energy Performance Certificate of a Building

The energy crisis has become a highly relevant global issue, and increasing attention is being paid to reducing energy consumption in buildings. In addition to environmental protection, the demand for energy savings is also driven by the significant increase in energy prices in recent years. In Slovakia, energy savings are largely influenced by the thermal protection standard STN 73 0540-2+Z1+Z2 (2019), which, by tightening the required values of thermal resistance and thermal transmittance of building structures, has led to extensive thermal insulation of building envelopes. However, improving the thermal performance of buildings is not the only way to reduce the overall energy consumption of buildings. This paper examines the recovery of waste heat from shower wastewater for preheating domestic cold water, together with its hygienic aspects and its energy, economic and energy-certification benefits for a high-occupancy sports facility.