At the same time, the total sample’s definition requires surveys and confirmation of the existent number of solar water heating systems. Therefore, a field research has taken place at the 3 cities, where specific questionnaires were used along with fabric and installation companies, commercial stores and customers. The statistic analysis is discussed later.

“Questionnaire A” was developed to raise the technical information, such as collector area sizing estimation, storage tank volume, collectors’ array and insertion in field, general conditions of operation and installation, and equipment maintenance and life cycle. Questions related to sociological and behavioral topics about the use of solar water heating generated “Questionnaire B”. With the creation of a website, dedicated to this project, it was possible to provide secrecy and appropriate ways to transfer and store the collected information.

To develop these questionnaires, important factors — as appropriate language and interest for all the social and economic classes — were included. The inquiry blocks used are illustrated in Figure 2.

The maintenance of this inquiry method in all questionnaires allows the comparative evaluation of the main problems detected. Through this strategy, economic, social, cultural, climatic and technological factors associated to solar water heating had become clearer and easier to understand.