Abstract
The building and service sector accounts for nearly 40% of total energy use in Sweden. The existing, historic building stock accounts for large part of this energy use and comprises an important part of the national pursuit to increase energy efficiency. One main problem for decreasing energy use in the existing building stock is the lack of data describing thermal performance characteristics. This paper presents a novel development of the change-point model for predicting the thermal performance of buildings using selected time periods based on time-dependent variations in climate and user behavior. The predicted thermal power characteristics include total specific heat losses (Qtotal), energy use for hot water circulation (HWC) and hot tap water (HTW), and balance temperature. A residential district with 73 historic buildings in Linköping, Sweden, has been used as the study object.The developed model is shown to be effective and robust for describing building thermal performance. The average R2 was 0.70 for predictions of specific heat losses. The sensitivity analyses conclude that the selected time steps and months correspond to the highest R2 value. The average variation width for prediction of the balance temperature is 0.9 °C for buildings in the interquartile range based on a three-year comparison of hourly heating power supply data. Moreover, from a property owner perspective, the model is shown to be useful for identifying deviating thermal power characteristics and can easily be used to get an overview of a district.
Highlights
Residential buildings are one of the main contributors to resource exploitation
In Step III, assumptions are made connected to the model in terms of building operation and user behavior, while Step IV consists of the numerical procedures during the selected time periods for differentiating thermal power characteristics
The thermal performance of buildings is often given as specific energy use annually
Summary
Residential buildings are one of the main contributors to resource exploitation. On a global level, it is estimated that buildings utilize 35% of the final energy use and contribute approximately one-third of CO2 emissions [1]. The existing building stock is identified as the sector with the highest energy savings potential within the European Union (EU) [2]. Despite the likely future increase in space cooling as a result of global warming [3], it is of interest to study the heating energy savings potential in residential buildings situated in Northern European countries due to their cold climate. This is especially the case when considering that comfort cooling is uncommon today in buildings used for residential purposes.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have