Energy use and environmental impact from hotels on Adriatic Coast in Croatia : current status and future possibilities for HVAC systems

Abstract: This thesis analyses a specific type of energy usage system, “energy usage in hotels”, and how this system behaves. In order to evaluate the current state of energy use in hotels, an energy audit questionnaire was developed and conducted among 31,5% of hotels on the Adriatic coast. The energy audit was used as a tool to set a benchmark for energy consumption in hotels and to identify opportunities for increased energy efficiency measures in HVAC systems. The analysis has shown that the average energy consumption in hotels on the Adriatic coast is in the range of 159 to 180 kWh/m2 and 162 to 225 kWh/m2 for seasonal and non seasonal hotels respectively. In order to establish a relationship between different independent variables in the hotels (total floor area and number of rooms) and dependent variables, such as electricity and oil consumption, mathematical statistical methods, such as correlation and regression analysis, were implemented. The objective of this thesis was also to develop - from an energy, environmental and economical points of view - a methodology for the design and retrofit of HVAC systems in the hotels on the Adriatic coast. The methodology named HOTECO is based on a system thinking approach. With respect to the technological aspects, the first step was to analyse conventional HVAC system designs and to compare it with the three most promising alternative HVAC systems utilizing renewable energy sources for a typical hotel. Computer modelling in TRNSYS was used to assess energy consumption. TRNSYS software has been used for simulations for a number of years, is internationally recognized, and has been validated and verified. It was concluded that energy and environmental savings in hotels on the Adriatic coast could be achieved using readily available technologies. The HOTECO methodology also demonstrated a framework that supports decision making iv regarding system selection and operational strategies to limit environmental impact from HVAC systems in hotels. Four scenarios for energy consumption in hotels on the Adriatic coast with regards to current state of energy systems and improved retrofit solutions utilizing renewable energy source were given.