The units minimise maintenance requirements and the use of long-life filters, so that annual maintenance inspections are sufficient. The outdoor AHUs, natural refrigerant circulation indoor units and decentralised air-conditioning units can be coordinated to operate as a whole, according to the patterns and the time periods that air conditioning is required. For example, a conventional heat-source system with refrigerators, boilers etc. The system installed at the town hall reduced the space required for machine rooms to 130 m 2 by utilising the roof and the inside of the ceilings. Cost savings for heating and cooling.
Thermal storage using night-time power produces excellent results.
The ice thermal storage system cuts energy costs by using inexpensive night-time power and by reducing the installed heat source capacity. A discount is also given as a result of a peak-time adjustment contract. See Figure 5 . Electrical demand shifting and levelling also lessen environmental loads by extending night-time power generation, thereby enhancing the efficiency of the power supply.