T. Selke1*, A. Preisler1 and U. Schneider2

1 arsenal research, Austrian Research Centre, 1210 Vienna, Austria 2

pos-architekten, 1080 Vienna, Austria
* Corresponding Author, tim. selke@arsenal. ac. at

Abstract

The usage of renewable energy booms not only in residential buildings, but also achieves more and more acceptance in commercial buildings. The building „ENERGYbase“(1) in the 21st district of Vienna, with 7.500 m2 useful area shows, how office buildings in the future may look like. The architectual and energy concept of the office building focuses on sustainable, innovative technologies as passive house standard for the building envelope, ground coupled heat pumps, free cooling, solar air-conditioning, building integrated photovoltaics and ecological air humidification by using plants in the ventilation system. The occupants of ENERGYbase building will be mainly business companies and institutions for research and education in the field of renewable energy.

To keep the primary energy demand as low as possible the energy performance of ENERGYbase concentrates on the use of locally available renewable energy sources. First geothermal heat is used by wells water for heating with heat pump and for cooling by free — cooling. The energy distribution system of the office building mainly operates by using thermal mass activation, therefore high efficiency can be achieved with the heat pump system, direct free-cooling is possible and also high indoor comfort by radiant heating and cooling can be provided. Solar energy is actively used three times in the south faced facade: solar-assisted air-conditioning in summer, heating support in winter and production of electricity all season long by photovoltaics. Therefore, the south facade is equipped with 300 m2 solar thermal collectors and 400 m2 photovoltaic panels. The special convolution of the south faqade allows on the one hand high solar gains in the solar active components and on the other hand the components performs as sun protection elements for the office areas behind.

Basic requirements for such an energy performance concept, is a solar and energy efficient architectural concept. The sum of actions begins with the big compact volume of 30.000 m3 and the solar orientation of the building shape. Several other parameters, which reduce the heating and cooling demand, have been taken into account from the very beginning as the thermal quality of the building envelope, low infiltration rate, quality of glazing and sun protection, sufficient storage mass, etc.

Nevertheless, the ENERGYbase building has a high ratio of glazing; the entitlement on architecture was to provide high daylight quality, to illustrate an intelligent and energy efficient design of direct sun light use in an office building.

As a consequence the heating and cooling demand of the whole building can be covered by the use of ground wells water and solar energy, only for the energy distribution additional electricity is needed. The building and its heating, cooling and air-conditioning system is equipped with a comprehensive monitoring system in order to evaluate the applied innovative technologies in operation and to identify further development demands.

Keywords: Sustainable, innovative technologies in office building, passive house concepts, ground coupled heat pumps, free cooling, solar air-conditioning, building integrated photovoltaic and ecological air humidification.

1. Introduction

The office building project ENERGYbase in Vienna is based on results of an Austrian research project »Sunny research« which was prelimary performed, funded by the Austrian research programme »Haus der Zukunft« and directed by arsenal research.