Survey of modern pellet boilers in Austria and Germany – System design and customer satisfaction of residential installations

• Published in: Applied energy Vol. 160; pp. 390 - 403
• Main Authors: Büchner, Daniel, Schraube, Christian, Carlon, Elisa, von Sonntag, Justus, Schwarz, Markus, Verma, Vijay Kumar, Ortwein, Andreas
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15-12-2015
• Subjects: Customer satisfaction; Heating system; Pellet boiler; Questionnaires; Residential customer; Statistical study; Residential customer; Heating system; Customer satisfaction; Statistical study; Pellet boiler; Questionnaires
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2015.09.055

•Legal framework conditions influence design of modern heating systems.•Operational behavior of pellet boilers is usually better in new buildings.•Majority of residential customers are highly satisfied with their pellet boiler.
The variety of available technical building equipment leads to increasingly complex heating systems with various requirements for efficient operation. Furthermore, in existing buildings the heating system is often historically evolved and contains parts having different ages. Those systems have limited capacity to suit the requirements of replaced components. This paper investigates the operational behavior of small-scale pellet heating systems in Austria and Germany, considering installations in new buildings and boiler replacements in existing buildings and how they are influencing the customer satisfaction.
This investigation was carried out by means of a comprehensive survey for residential customers using pellet fired heating systems. More than 2500 questionnaires were distributed between 2011 and 2013 in Austria, Germany, Greece, Spain and the United Kingdom. In total 293 returned questionnaires were evaluated. The efficiency of the monitored heating systems was estimated using surveyed boiler parameters. Successively, the influence of different operational parameters on the boilers efficiency was evaluated with a statistical analysis, using Pearson correlation coefficient and Spearman correlation.
Results showed that the correct installation of the monitored pellet heating system is easier for new buildings compared to the replacement of old fossil boilers in existing buildings. Optimal operating conditions are characterized by less frequent ignitions and by higher operational loads. Pellet systems operated with a high efficiency in both building types, but for new buildings it is more likely to occur. More than 87% of the participating customers stated that they are highly satisfied with their pellet boiler.