The typical Japanese home is today installed with an average of three air conditioners, keeping air inside cool and dry even through the hot, sweltering heat waves that hit large cities in the summer. A hundred years ago, however, no such air conditioners existed in Japan. The country's first commercial air conditioner was installed in 1923, in the Hogakuza, a movie theatre that was located in central Tokyo. RIKEN played a central role in the creation of this first air conditioner with its invention of Adosoru.
Adosoru is a desiccant, a substance that absorbs moisture and promotes drying, made from a special type of clay that is highly porous and absorbent. Masatoshi Okochi, the innovative president of RIKEN in its early days, was sure this was a material that could be put to use in business, and in 1922 he established a company named Toyo Gas Shikenjo to find commercial applications for Adosoru. The first major application of Adosoru was in the air-conditioner that RIKEN researchers installed in the Hogakuza, a system carefully designed to accommodate the 1000-person-capacity of the theater. The popularity of this first air-conditioner in Japan led to further installations of Adosoru-based air-conditioning systems at other locations.
The development of Adosoru was carried out by a research group led by Kikunae Ikeda, inventor of monosodium glutamate (MSG), and Hajime Isobe. Toyo Gas Shikenjo, a company created to find commercial applications for Adosoru, was RIKEN's very first spin-off business and the seed that would grow into the famous RIKEN Konzern with more than 63 companies. RIKEN's contributions to society began with Adosoru.