The purpose of this paper is to present the basic data relating to the reliability of the air-conditioning and sanitary installation at two large-scale office buildings. We got the maintenance record data of A-building, its total floor area is 74,827m^2, observation term is 1,795 days, and of B-building 142,759m^2, 3,910 days. The number of failures and troubles occurred at the air-conditioning installation of A-building and B-building during the observation terms are 537 and 1,913 respectively. And at the sanitary installation, 562 and 2,736. At first, the characteristics of the occurrence of failures and troubles of the air-conditioning and sanitary installation were grasped. Then the Weibull analysis were adopted to the time between failures and troubles data. The Weible distributions of the time between failures and troubles of office area were obtained. The data includes monthly number of failures and troubles at B-bldg. since building completion. Using the data, "failure rate curve" of "early failure period" of B-bldg.'s air-conditioning and sanitary installation were formulated. The distribution of repair time were also gotten. The reliability of the air-conditioning and sanitary installation of A- and B-building were totally clarified.

View full abstract

This paper examines the variable speed pump's control method to realize stable driving of the heat source system while enabling reduction of the water transportation power in primary water system by controlling flow rate and differential pressure between the header. This control method construct feedback control to control differential pressure between the header by a bypass dialect divergence and feedfoward control which operated driving frequency by heat souse system's P-Q model (including Pump P-Q property, Heat Souse machinery and others resistance). This control method is possible to controlling flow rate and differential pressure between the header in heat souse system which constructed different capacity and model or type machinery coexisted. This control method is possible to controlling flow rate and differential pressure between the header in heat souse system which constructed fixed flow rate and variable flow rate machinery coexisted. We examine that this control is practical use and useful by some experiments, and effect on saving energy by building model.

View full abstract

This study examined indoor thermal environment and energy saving of desiccant cooling system using solar thermal and well water. And this paper describes a result of field survey of desiccant cooling system in summer. As a result of having compared a conventional air conditioning with this system, room temperature and humidity were kept low and about 17% of cooling load of the air-conditioner was reduced. In addition, the rate of fresh air load to the cooling loads was about 40%, and this system reduced about 113〜136kWh/day of fresh air loads and this system reduced about 100% fresh air loads. From these results, this system is effective to reduced fresh air loads and this system is excellent in both indoor thermal environment and energy saving.

View full abstract

The CO_2 emission associated with hot-water supply is a major component of the emission attributed to housing equipments; therefore, the design of the bathroom, which is the greatest source of hot-water usage, has a significant influence on the overall emission levels. Bathroom appliances have developed with satisfying both user's comfort and water- and energy-saving performance. During remodeling of a residence, selection of the most recent water- and energy-saving appliances for the bathroom can reduce both the annual running cost (32,975 yen) and the average CO_2 emission (373kg) for a house. Although various measures have been implemented to reduce global warming, there are no proposals relevant to housing equipment, which is responsible for about 23% of the CO_2 emission associated with everyday activities. During remodeling of bathrooms, selection of appliances with high water- and energy-saving performance is an effective housing-equipment-related environmental measure to reduce global warming.

View full abstract