Today, sustainability and energy efficiency are of prime importance in satisfaction of thermal and electrical loads of buildings. In this study, innovative hybrid solutions alternative to conventional HVAC systems are investigated. Objective of study is to minimize the payback period and CO2 emissions are main objectives. For conventional HVAC systems two sources of energy, namely natural gas and electricity were considered as the base line. Energy sources for the innovative methods were considered to be solar energy, ground heat and waste heat. Conventional system was considered to be a backup system when innovative energy resources are insufficient. Hourly heating, cooling and electrical power loads of Eser Green Building, which already has LEED Platinum certificate were used for the case study, which aims to further improve the energy and exergy efficiency. In the new algorithm being developed, all power conversion systems were defined in a simple input- output transfer function format. A decision-making algorithm and an ExcelTM-based simulation program were developed and tried with Eser Green Building input data for different renewable energy source and system combination conventional systems, energy sources, and equipment in term of investment, operation and total cost, payback period, and carbon dioxide emission values. Payback period of Eser green building is 11,8 years and for two hybrid systems are 13,2 years and 9,2 years, respectively. Carbon dioxide emissions by hybrid systems under the same load conditions were found to be 488 kgCO2/h and 592 kgCO2/h for approaches, respectively.
Timed-Automata Based Model-Checking of a Multi-Agent System: A Case Study