Holistic renovation and monitoring of residential buildings

Panel: 5A. Cutting the energy use of buildings: Projects and technologies

This is a peer-reviewed paper.

Authors:
Davide Cali, EBC - E.ON Energy Reasearch Center - RWTH Aachen University, Germany
Tanja Osterhage, E.ON ERC EBC RWTH Aachen University, Germany
Rita Streblow, E.ON ERC EBC RWTH Aachen University, Germany
Dirk Mueller, E.ON ERC EBC RWTH Aachen University, Germany

Abstract

A large number of buildings constructed in the second half of the twentieth century consume big amount of energy due to low insulation standards and obsolete heating systems.

In this work the holistic renovation and the results from the monitoring activity of three identical buildings, located in Karlsruhe, is presented. Each building has three separate entrances, each entrance has ten apartments over five floors. The buildings were built at the end of the fifties, had no external insulation, “single glass windows”, a single cackle stove per flat and water flow heaters.

The buildings have been retrofitted with seven unique refurbishment layouts: one layout for the first building, one layout per entrance in the second and the third building. The layouts differ for insulation (inter alia “passive house” windows, foam insulation, vacuum insulation panels), heating engineering system (district heating, CO2-probes heat pumps, air to water heat pumps, exhaust air to water heat pump) and ventilation system (exhaust fans, waste heat recovery systems).

The monitoring system collects data about comfort conditions in rooms (temperature, relative humidity, CO2, VOC, window position, brightness) and energy flows at delivery, distribution, storage and generation level with a one minute time step.

The variety of the refurbishments’ layouts, combined to the high time resolution monitoring system, enabled deep analyses of refurbishment technologies under real conditions: The so called “rebound effect” has been identified and quantified for each refurbishment solution.

In average, depending on the refurbishment layout, the buildings consume 10 to 40% more than expected, while a much bigger discrepancy has been found analysing energy consumptions at apartment level. This work shows how users play a very important role in the energy balance of buildings: technologies can influence user behaviour, users influence technologies efficiency.

BMWi financial support (03ET1105A)