Acceptance and improvement of low-energy-house components as a mutual learning process for users and producers

Status

finished

Summary

To reach very low levels of energy consumption (below 30-40 kWh/(m².a)) in residential buildings, balanced ventilation systems with heat recovery are needed, as otherwise energy loss through ventilation and air leakage would make the target impossible. In some cases (especially passive houses) even room heating is provided through the ventilation system. Occupant acceptance of balanced venti-lation and attached heating systems will strongly influence the chances of the wide dissemination of very low energy buildings.

The aim of this research project is to evaluate the experiences of users of balanced ventilation sys-tems in residential low energy buildings, to analyse the pre-conditions which influence occupants' acceptance of ventilation and heating systems, and to develop strategies to support the wide dissemi-nation and user-friendlier design of these low energy house technologies.

Successful dissemination strategies will in the long run depend on technical and planning concepts that better match the needs and expectations of users. One of the central claims that this research project will make is that the eventual improvement of low energy house technologies will have to be organised as a mutual learning process through which component producers and users (users in a wide sense, i.e. professionals, companies, building societies, etc.) must go. Based on concepts previously developed, such as the Dutch programme 'Constructive Technology Assessment' or von Hippel's 'lead user concept', the proj-ect report will also sketch possibilities for broadening the design process of technologies by actively involving various types of users.

Methods and project steps

1. Social survey of the levels of acceptance on the part of the residents of low-energy-houses of controlled ventilation and heating systems; quantitative analysis of 144 questionnaires from residents of single-family houses and blocks of flats; in-depth interviews with 30 residents.
2. Market research based on a qualitative analysis of interview data employing the GABEK-method to design appropriate marketing strategies.
3. Interviews with building experts, e.g. component manufacturers, planners, architects, building professionals and building societies, regarding barriers and opportunities for the wider dissemina-tion of ventilation systems in Austria.
4. Development of strategies to involve users in technology innovation processes on a broader and more systematic basis.

Main results

Overall satisfaction with balanced ventilation systems is very high (especially in single-family houses where more than 90% of the occupants would install a ventilation system again). Neverthe-less, a significant proportion of the residents interviewed reported negative experiences - predomi-nantly noise (41% even of single-family home residents!) and lower than acceptable humidity levels. They also expressed dissatis-faction with the control system. Problems and complaints are significantly higher in multi-family buildings, where occupants never took a conscious decision in favour of balanced ventilation and usually did not get enough information about the function and usage of this technology. Moreover, many of the blocks of flats investigated are social housing projects which were built under high cost pressure, sometimes resulting in dysfunctional or badly working ventilation systems. However, it is a good sign that experiences and satisfaction with balanced ventilation improves significantly with newer systems which have been built during the past few years.

Most problems with ventilation systems do not result from inappropriate technical components, but depend on the quality of the planning and construction process, the integration of the ventilation system into the general concept of the building (energy concept, design), the state of information of the users, cost pres-sure, the balancing of the system after completion etc. Though remarkable learning processes and know-how improvement on the part of specialised planners, architects and building societies can be observed, the majority of the relevant professionals do not have sufficient competence and know-how (espe-cially in the case of heating provided through the ventilation system) to meet high quality standards yet.

Strategies to improve the quality and dissemination of ventilation systems in low energy houses, there-fore, will have to focus on several different levels:

a) Improving the socio-economic, legal and organisational context of balanced ventilation technolo-gies, i.e. know-how of professionals (training programmes, certification, quality standards), regula-tions (acceptable noise levels, the way planning fees are calculated, the structure of subsidies for low-energy buildings), moving towards integrated planning processes, shaping the expectations of potential users and building societies through marketing programmes.

b) Systematically integrating experiences and expectations of users of balanced ventilation systems into the further development of the product and of planning concepts. User involvement may occur at a more general level of product development through surveys, focus groups or 'lead user' workshops, or it may be employed at the levels of building planning, construction and use: experienced users from other buildings or prospective users should be more actively involved in the planning process of the building.

c) Taking into account product perceptions of customers who decided against purchasing a balanced ventilation system when creating marketing and information concepts for producers, installers or energy advice agencies. Non-customer perceptions often differ remarkably from the experiences of users. To take one example, a serious obstacle to the installation of a ventilation system is the expectancy that there will be a problem with drafts. This problem is not taken into account by users or suppliers though, as it does not exist in reality.

Contact

Harald Rohracher
IFZ - Inter-University Research Center
Schloegelgasse 2
A 8010 Graz
Tel.: +43 316 813909-24
Fax: +43 316 810274
E-Mail: Rohracher@ifz.tu-graz.ac.at