Energy Performance Modelling and Heat Recovery Efficiency Assessment : 9783659781438 : 25 Sep 2015 : This extended research investigates and analyzes a typical multi-zone office building's annual energy performance. The aim is to evaluate the HVAC system's and HR unit's performance in order to conduct the most efficient heating and cooling solution for temperate climate conditions. The energy performance of four HVAC system types (heat pump - air to air, gas - electricity, electrical and fan coil system) were analyzed, compared and evaluated on a virtual office building model in order to assess the total annual energy performance and to determine the efficiency of the HR unit's application. Further, the parameters of an energy efficient building envelope, HVAC system, internal loads, building operation schedules and occupancy intervals were implemented into the multi-zone analysis model. The investigation was conducted in EnergyPlus simulation engine using thermodynamic algorithms and