H. Roh1*, K. Suzuki1 and M. Udagawa2

1 OM Environmental Planning, 4601 Murakushi-Cho, Hamamatsu-City, Shizuoka-Prefecture, 431-1207,

Japan

2 Kogakuin University, 1-24-2 Nishi-Shinjuku, Shinjuku-Ku, Tokyo, 163-8677, Japan

* roh@omsolar. jp
Abstract

This paper describes the development and the field test of a solar desiccant cooling system for small office building. The main purpose of this system is the process of the fresh air heat load and the getting cool to dehumidify the fresh air. This system is composed of two air handing units with two desiccant modules and is operated in regeneration process and in dehumidification process at the same time while the operation mode is switched. Solar heat is used for the regeneration of desiccant module and well water is used for cooling the air passed through the desiccant module. From the monitoring results, the fresh air heat load of 73% was reduced by the effect of the solar desiccant cooling system. From the field test results, it was found that the reduced daily electric power consumption of the electric heat pump air conditioner (EHP) was 36% for the operation of the solar desiccant cooling systems compared with the operation stop. In winter, these solar desiccant cooling systems are used for the solar space heating systems. From the field test results in winter, the reduced daily electric power consumption of the EHP was 40% for the operation of the solar space heating systems compared with the operation stop.

Keywords: solar thermal, desiccant, cooling, well water

1. Introduction

The common air-based solar thermal system is useful for space and DHW heating, whereas the collected solar thermal energy is almost exhausted to outdoor except heating DHW in summer. For using the solar thermal energy available throughout a year, the solar desiccant cooling system has been developed for the pre-cooling system of fresh air to dehumidify fresh air with ventilation in summer. In addition, this system is used for solar space heating system to heat fresh air with ventilation in winter. This system was installed at the field test office building in the central area of Japan. The mechanism of the solar desiccant cooling system and the results from the field test is introduced.