The Calculation of the Seasonal Performance Factor (SPF) of a Domestic Hot Water Heat Pump Integrated with a Mechanical Ventilation Installation with Heat Recovery for a Residential Premises in the EnerPHit Standard

The existing residential premises located in the attic in Poznań , owned by a private person, was qualified for deep energy modernization due to high energy consumption and related costs. The goal was achieved by thermal modernization of the premise s to the EnerPHIT standard according to the Passive House Institute in Darmstadt. One of the most important elements of the ene rgy modernization was the installation of mechanical ventilation with heat recovery, which was integrated with the installation o f a heat pump for heating domestic hot water. In the summer, the domestic hot water heat pump it receives heat from the air blown into the object's volume, contributing to its cooling, this is the so - called discharge cooling - free of charge, created as a result of heating domestic hot water. In transitional periods and in winter, the domestic hot water heat pump extracts heat from the ventilation air discharged from the building. Exhaust air has a greater energy potential than outside air because it is warme r and more humid. The paper presents estimates of energy (savings of approximately 7,3 % of electrical energy consumed), economic (SPBT = 1.92 years), and environmental (7.8% reduction in CO2 emissions) benefits related to implementing this solution for t he residential premises in question in Poland. The presented solution contributes to sustainable development goals because it minimizes energy consumption and reduces CO2 emissions, which is important. It also decreases running costs, while the investment itself is modest .