Abstract In this study, a questionnaire and interview survey were carried out with respect to facilities for the elderly from the perspective of air-conditioner manufacturers, in order to determine whether or not it would be possible to improve thermal environments in such facilities through the development of a new air-conditioning apparatus for those facilities. Consequently. we found that there were many kinds of problems, such as indoor temperature differences, drafts, dryness of air and odors. Based on the results of the survey, an air-conditioning system which ‘utilizes the underfloor space’ for the air conditioner apparatus was developed. The results of measurements of room temperatures indicated that, by using this system, room temperature distributions were smaller in comparison to cases where traditional air-conditioning apparatus were used.