1990 Volume 15 Issue 44 Pages 23-35
An investigation with questionnaire was conducted in summer and winter in order to find out the problems of present home water heaters and their proper design route. The subjects of the investigation are the inhabitants of apartments constructed by the Housing-Urban Development Corporation (HUDC), that construcued by private companies equipped with an overall central heating system for hot water supply, and detached houses, which covered 21 areas in total. The respondents were selected in consideration of a balanced mix of the kinds of home water heaters with the cooperation of HUDC and Tokyo Gas Co. Ltd. The valid replies amounted to 477 in the summer survey and 319 in the winter, and were classified into 8 groups according to the hot water supply systems. The results are summarized as follows. 1) In the case of filling bathtabs, the lack of hot water flow rate mostly spoils the comfortableness. 2) Hot water temperature of 60℃ is nearly satisfactory, except for special purposes such as removing oil stains. 3) The capacity of instantaneous water heater should be held down to class-4 (output of 6000kcal/h) for the sake of convenience. 4) The present level of temperature control systems is not considered fully satisfactory, especially for taking showers. 5) Water temperature or flow rate fluctuates most frequently in case that hot water is used in two or more places in the same apartment, irrespective of kind of water heating equipments. 6) In selecting an instantaneous water heater for installed central system, attention should be paid not only to its heating capacity but also to the controllability of water temperature. Automatic water temperature control as well as the heating capacity reduction devices are desireble for the comfortableness of users. 7) Most users wash their tableware and their face with the running water. 8) Showers were taken at a relatively high frequency although it is only recently that showers began to be equipped in Japanese homes. 9) Among the users of heating systems which share the same heat source for hot water supply and for room air-conditioning, the cost of fuel for the hot water supply is considered that it is a financial burden, however, can be made up for due to the improved convenience. 10) The most users replied that they were satisfied with the present water heating equipment as an overall judgement, especially for its convenience.
