HVAC&R systems are the most energy consuming building services, representing approximately half of the final energy use in the building sector. Despite their significant energy use, there is a lack of a consistent and homogeneous framework to efficiently guide research, mainly due to the complexity and variety of HVAC&R systems, but also to insufficient rigor in their energy analysis. Quantifying the energy consumption characteristics of HVAC&R system is complicated, because the energy savings provided by this system depend on various factors. This research evaluates energy consumption characteristics of HVAC&R systems, with the aim of establishing a common idea for the analysis of building energy efficiency. The objective of this study is to develop an energy evaluation methodology and a simple simulation program that may be used by engineers and designers to assess the effectiveness and economic benefits of HVAC&R systems. Our approach deals with the concept of HVAC&R system energy use aggregation levels that are composed of subsystems. To carry out a techno-economical estimation of HVAC&R systems considering different types of subsystems, the matrix combination analyzed, and a total of 960 HVAC&R systems can be implemented for a large-scale office building. The methodology of energy analysis that was carried out in this study highlights how to plan and design toward utilizing the most effective HVAC&R systems. (C) 2014 Elsevier B.V. All rights reserved.