Proper commissioning of the energy systems in a commercial building is a key to efficient operation (Koran, 1994; Kjellman et al., 1996; IEA, 2005; Roth et al., 2005). Building commissioning is a quality control process that begins with the early stages of design. Commissioning helps ensure that the design intent is clear and readily tested, that installation is subjected to on-site inspection and that all systems are tested and functioning properly before the building is accepted. A systems manual is prepared to document the owner’s requirements, the design intent (including as-built drawings), equipment performance specifications and control sequences.
Recent results of building commissioning in the USA showed energy savings of up to 38% in cooling and/or 62% in heating and an average higher than 30% (Claridge et al., 2003). A study by Mills et al. (2005) reviewed data from 224 US buildings that had been commissioned or retro-commissioned. The study found that the costs of commissioning new buildings were typically outweighed by construction cost savings due to fewer change orders and that retro-commissioning produced median energy savings of 15% with a median payback period of 8.5 months. It is very difficult to assess the energy benefits of commissioning new buildings due to the lack of a baseline.