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Lighting in need of care

Many homes for elderly people have not been refurbished and are often equipped with inefficient lighting systems that do not accord with energy requirements or health aspects. In this part of the joint project researchers investigated and assessed the lighting situation in two retirement homes in Berlin. The concept behind the homes is that the residents should spend as little time as possible in their own rooms during the day. For this reason most spend almost the entire day in centrally located, large-sized common rooms. Quantitative surveys were conducted with the residents in the retirement homes in regards to their comfort and meeting visual tasks. The evaluations were based on surveys with various scenarios for general lighting with two different colour temperatures for the lamps used (warm white: 3,000 K and cool white: 6,500 K).

Here it was shown that warm white light with a vertical illuminance of just 100 lx was felt to be pleasant during the mornings and afternoons both in winter and early spring. Values of 500 lx and more were felt to be too bright. In the case of the cool white lighting, the respondents tended to find this too cool at the beginning of the year but found it just right during the other months. However, the residents found the vertical illuminance of 100 lx to be too dark from summer to December.

When presented with large-sized texts (Arial, 14 pt), all respondents assessed their reading ability as „good“ under all lighting conditions, i.e. for both the warm and cool white light, and with all applied horizontal illuminance from 150 to 1,000 lx. However, with small and medium font sizes (Arial, 12 and 10 pt), the appraisals were more differentiated: whereas 80 to 90 % of the respondents described their ability to read texts with 12-pt fonts as „good“ for all lighting conditions, in the case of the smaller text (10 pt) the cold white lighting was found to be better than the warm white lighting.

Architectural and energy optimisation

In Germany there are around 12,000 homes for elderly people with more than 840,000 places for the elderly and people in need of care. Around half of these homes have not been modernised in the last 20 years. Particular disadvantages of the buildings include their antiquated construction, lighting systems, building services equipment and plant technology. Increasing energy costs have also become a tangible cost factor in retirement and nursing homes, and present operators and funding bodies with the task of reducing costs and using energy efficiently while maintaining the same quality standard. State-of-the-art buildings are essential if residents are to feel comfortable in an institution. Faced with the demographic change and the increase in nursing costs, refurbishment concepts for nursing accommodation are an essential task for the future.

As part of a joint project, researchers are therefore developing concepts that contribute to holistic, sustainable and energy-based refurbishment measures and to the further architectural development of residential care facilities. In collaboration with the Centre for Sustainable Energy Technology (zafh.net) at Stuttgart University of Applied Sciences and further partners, the intention is to develop energy-based, health-promoting, economic, ecological and design-based solutions, and to compile them in formative guidelines for assessing the feasibility and evaluating sustainable refurbishment concepts.

The current project forms part of the „Energy-Optimised Construction“ (EnOB) research initiative. Together with Osram and the Evangelisches Altenzentrum in Bruchsal, the project is scheduled for completion in 2016. It is the second flagship project in the field of old-age care provision to be funded by the German Federal Ministry of Economics and Technology and is intended to provide a comparison basis for all other institutions with similar uses. In this project the building services will be replaced with new, efficient components that are based on an intelligent building automation concept and which work with renewable energy sources. This will therefore lower the primary energy requirements for heating. After implementing the new systems, they will be monitored for two years, which will enable forecasts and measurement values to be compared with the actual operation and ultimately enable the final operation to be optimised.


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Project management
TU Berlin, LI

Project partner