Energy-Optimised Building- Experience and Future Perspectives from a Demonstration Programme in Germany

In 1995, the German Federal Ministry of Economics and Technology launched an intensive research and demonstration programme on energy-optimised construction of new buildings as well as retrofitting the building stock. Beside research on materials and components, approximately 50 demonstration buildings covering various building typologies have been realized and monitored within the programme (www.enob.info). Accompanying research was conducted to systemise the results and lessons learned. The programme led to a set of prominent research results in the fields of e.g. daylighting, passive cooling, energy efficiency and renewable energy use in commercial buildings, user behaviour and user satisfaction. Many of the demonstration projects have reached energy savings of 50% and more compared to current practice in Germany, without exceeding conventional investment costs. A number of these projects have been awarded architectural prizes. This paper summarises key findings and explains the strategies for new projects on the route toward net zero-energy buildings. These strategies are based on a further decrease in energy demand and increased renewable energy utilization in conjunction with intensified use of building-integrated power generation interacting with the public grid

System description, categorization, and comparison

This chapter presents possible ways to analyze and categorize existing and even future solar and heat pump (SHP) systems. There are five main criteria to describe a solar and heat pump system: the type of heat demand to be served; the low-temperature heat source(s) of the heat pump; the form(s) of energy used to drive the system; the function and placement of storages in the system; and the interactions between these components. The chapter introduces a graphical representation to systematically analyze and compare solar and heat pump systems. It presents statistical analysis of market-available solar thermal and heat pump systems. The chapter deals with the question to what extent SHP already penetrated the market. Results can be stated either in absolute numbers or relative to conventional systems, that is, non-solar and heat pump systems. Here, it is evident that the industry follows theoretical considerations in both ecology and economy

Design of passive cooling by night ventilation: evaluation of a parametric model and building simulation with measurements

At the new institute building of Fraunhofer ISE, both mechanical and free night ventilation is used for passive cooling of the offices. The results from a long-term monitoring show, that room temperatures are comfortable even at high ambient air temperatures. In two offices, experiments were carried out in order to determine the efficiency of night ventilation dependent on air change rate, solar and internal heat gains. The aim is to identify characteristic building parameters and to determine the night ventilation effect with these parameters. The experiments (one room with and one without night ventilation) are evaluated by using both a parametric model and the ESP-r building simulation programme. Both models are merged in order to develop a method for data evaluation in office buildings with night ventilation and to provide a simple model for integration in a building management system