Analysis of energy consumption in single family houses

This article deals with estimation of the thermal characteristics of single family houses based on measurements of energy consumption and climate. The thermal characteristics includes the response of the building to changes in temperature (UA-value), solar radiation (gA-value), and wind (wA-value). The effect of the wind is characterized both in terms of the wind speed and the wind direction, implying that wA-values are estimated for different wind directions.

In case only stationary characteristics are of interest it is sufficient to base the estimation on 24 hour averages, whereas in order to estimate the dynamic effects averages with a sample period around 4 hours are required. Also, it is beneficial to use measurements of the total energy consumption (heat and electricity).

However, in most cases it results in adequate estimates if only the heat consumption is used as the response variable. Obvious exceptions are cases where e.g. electrical floor heating is used for some periods. The estimated thermal characteristics have been analyzed with respect to background information regarding the households.

The information is obtained via questionnaires and via the Danish Building Register (BBR). The significant effects are the ground area of the house, the year of construction, and the number of times per week a wood burning stove is used. Consequently, given information regarding the use of wood burning stoves which consumers share, the estimates can be corrected so that adequate values are obtained even for houses where a wood burning stove is being used.

The article includes a short outline of how the methods could be integrated in an inter- active service such as “My E-Home” minbolig.elsparefonden.dk.