The paper presents a project of the ventilation and air conditioning system of the McDonald's restaurant building around the Vrbani area in Zagreb. The building spreads over two floors which contains of kitchen, restaurant and office space and the net surface of the building is 1050 m2. Ventilation requirements for the kitchen space are determined according to the installed equipment using the EN 16282-1017 standard and the amount of air that needs to be removed is equal to 9000 m3/h. For restaurant and office spaces, ventilation requirements are defined using ASHRAE Standard 62.1-2013. The amount of supply air for the restaurant space is 12500 m3/h, and for offices 2000 m3/h. In addition, a ventilation system for sanitary and storage spaces has been designed according to the experienced number of air change rate of 4-8 1/h. Based on the obtained values, the dimensions of the air distribution ducts were calculated according to the method of constant air velocity in the ducts. In addition, the positions and method of air intake and extraction are defined. Pressure drops were calculated on critical sections according to which fans for air conditioning chambers and air extraction from toilets were selected. The entire process of air preparation before entering the room is defined in the h-x diagram taking into account the constant air intake temperature of 18 °C throughout the year and the external design temperature according to meteorological data for Zagreb. In this way, it was possible to determine the required dimensions and characteristics of the components to be installed in the air chambers, providing maximum utilization of heat recovery. The appearance and arrangement of components inside the chambers were determined in cooperation with the company Proklima.