Prediction of the HVAC Energy Demand and Consumption of a Single Family House with Different Calculation Methods

In this study a comparative energetic analysis is investigated of a single family house with different calculation procedures. One of the methods that were used is the Ministry without Portfolio Decree No. 7/2006 for energy certification and MSZ-140-04 for energy demand calculations (by using WinWatt computer software) that are a widely used in the Hungarian practice by HVAC designers and experts. Passive House Planning Package (PHPP) is also more and more common used PC software in Hungary due to the continuously tightening energy requirements. To see the differences and imperfections between these methods the heating, cooling and ventilation system was designed of a given single family house and the annual energy consumption was investigated with these methods. To perform the investigation in more detailed three different heating systems were designed. In the first case the heat source is a condensing boiler operated with floor heating. In the other two cases the thermal systems are heat pumps with floor and ceiling heating. One of the heat pumps is an air-to-water system, the other one is a geothermal heat pump. The advantages of the heat pumps are that heating, cooling and domestic hot water energy is produced by only one equipment and efficiency. However comparing investment and operating costs for the heat pumps with gas boiler the payback time is very long based on this study. The investment costs, payback periods are investigated for the three different systems evaluating the results also with PHPP and WinWatt computer software tools in this study.