Monitoring started at the end of July 2006, thus results are presented for August 2006 onwards. The heat flows in all hydraulic loops have been measured with calibrated sets of flow meters and temperature sensors. The air flow through the stove has not been measured. Instead, the measured values from the lab for the stove efficiency have been used to calculate the flue gas heat losses based on measured pellet use. Heat transferred from the stove directly to the building was

calculated as the balance of the pellet energy and the flue gas losses together with the measured heat transferred to the water loop. Two separate electrical meters were installed to log the electricity consumption of the system and the electrical auxiliary heater. A simple pyranometer has been used to measure the solar radiation. A number of temperature sensors have been installed to give additional information about the status of the system components and the functioning of the system. Figure 2 shows the REBUS system schematic with sensor positions. The electrical meters and the pyranometer are not shown. The data were logged using a Campbell CR10 data logger with attached multiplexers. Average data values were stored with an interval of one minute.

The owner has kept good records of bought energy for the year previous to the installation, and these values are presented in some of the figures. The amount of wood used was estimated by the user and the tiled stove was assumed to have an efficiency of 50%.