Simulation analysis of energy requirements in HVAC systems used in commercial and community buildings

Energy requirements for HVAC systems operation in buildings must be known on account of the necessity to determine the operation costs of the buildings and to carry out analyses aimed at improvement of design conceptions applied in buildings and installations as well as their operational parameters. It is commonly assumed that the most useful tool for such analyses is a detailed simulation model: building HVAC system. However, the number of details included in the model makes the analyses very labour demanding and may result errors when preparing simulation data. In many cases simplified models may be equally useful if they reveal main directions of energy demand changes and values when analysing the essential factors. The paper compares the results of energy analyses made with the use of TRNSYS and with the use of a simplified model called "ideal" in some selected existing commercial and community buildings. The effect of the building construction, of indoor climate parameters as well as of the amounts of the supplied and fresh air are tested. Then the results are discussed.