The main task of the graduation thesis was to calculate the frequency of switching the heat pump and solar collectors in the heating period and cooling period. The graduation thesis is divided into two parts,in the first part which deals with the theory and the second is practical part. The first part describes the principle of heat pumps with supported schemes, explains energy sources and mode of operation and makes a table of advantages and disadvantages of such systems. After that, the chapter of solar systems with solar collectors, show us their basic elements and the principle of work. The practical part begins with the presentation of meteorological data for the selected area the city of Varaždin. The project parameters are given based on the collected data for the period since 1991 to 2010. The eventual heat pump and solar collectors are selected based on the input parameters. In order to enter the budget, the heating and cooling period is defined, after which data on average hourly, daily and monthly temperatures are collected for that period, and the same procedure is done for insolation of a certain area, due to availability, data for 2015/16 are taken. Data on average temperatures and insolations are classified in a period of 10 divisions for a given month. With this data, certain parameters are calculated and conclusions are made on the synchronization of heat pumps and solar collectors based on the achieved results.