Modelling of a gas-fired heating boiler unit for residential buildings based on publicly available test data

Abstract Despite being seen as an extinguishing technology, gas-fired heating boiler units are still one of the most common sources for meeting the space heating energy demand of residential dwellings. Current energy performance assessment calculations for residential buildings are often based on insufficient details with thermodynamically ambiguous assumptions and lacking of a consistent approach. However, more detailed methodologies usually require a large set of scarcely available input data which vastly limit the (re)usability of these more refined methods. Following the limited availability of design parameters provided by manufacturers, the goal of this research is to determine the necessary level of the modelling detail to reliably predict the performance of gas-fired condensing boilers. A thermodynamically consistent model of a gas-fired condensing boiler unit is developed and discussed through its application in numerical simulations. Calibration is done by using publicly available data and standardised measurement points are used for verification of the results. The values of the exhaust gas temperature and flow rate of the formed condensate are available in the standardised experimental reports of these units. This work suggests that these values should be included in public documents given by the manufactures.