Commissioning and Fault Detection of HVAC Systems by Using Simulation Models Based on Characteristic Curves

In order to reduce the energy demand in the field of heating, ventilation and air conditioning many efforts have been made during the last decades. HVAC-components used nowadays are much more advanced than those used years ago. The success of the energy saving endeavors becomes even more apparent if the controlling devices, and there especially the implementable controlling strategies, are put in the center of view. In former times the controlling appliances in HVAC-systems consisted of analog devices which were relatively inflexible in regard to varying controlling strategies. Nowadays the HVAC-appliances are controlled by digital systems. These systems enable building operators to run a building - and its HVAC-systems - with sophisticated controlling strategies which can be adapted to the needs of the occupants and to the use of the building. Further on, it is possible to use these devices for monitoring the building performance without much additional efforts. Commissioning is done to ensure that systems are operating in the way they are designed for. But in opposition to the described improvements on the system level the practice of commissioning has not changed throughout the years. In the following it will be shown that the traditional commissioning methods are overcome. Therefore, a different approach for commissioning will be presented. Further on, a detailed description of the basic tools used in this approach is given. These tools have been developed at the University of Stuttgart.