2023/08/15 Our wind tunnel (50x50cm, 1.5m long) was completed in 2007 with a research project budget from Hisashi Nemoto of Saitama Prefecture Expt Station. It has contributed to several projects, and recently, Dr. Miyamoto (now at Tokyo University of Marine Science and Technology) conducted an experiment on the theme of "The Role of Visual Stimuli in the Orientation Behavior of the smaller tea tortrix" which produced good results. The main features of the system are that the air in the tunnel is purified by an activated charcoal filter before flowing through it, and the air speed can be controlled from 10 to 50 cm/sec. Even under low-humidity conditions in winter, experiments can be conducted in mid-winter because the room is equipped with a large humidifier. As for the stability of the airflow, we have made several efforts to create a laminar airflow. So, if you are interested or planning to build a wind tunnel system, please come and see it. We have to create airflow using the air conditioner of that room or facility, so we have to consider the flow path on a case-by-case basis. Before our wind tunnel was built, we did not have an activated carbon filter and used a ventilation fan to exhaust the air outside, and we also used a ventilation fan to exhaust the air from the mouse breeding room next door. The exhaust from the adjoining mouse room was also exhausted by a fan. Since the exhaust was in a relatively busy part of the campus, odor became a problem, and we were instructed by the university not to use the ventilating fan. Our ventilation fan was also closed in the aftermath. When we had no choice but to build a new wind tunnel, we attached the wind tunnel outlet to the exhaust port of the air conditioner, so that the air flow could be controlled by a valve. This system was just right for our desired wind speed and we have been using it for a long time. I have a few more know-hows that I would be happy to discuss with you. By the way, the most expensive wind tunnel I have ever seen (for insect experiments only, of course) is the one owned by the Chemical Ecology Group of the Max Planck Institute in Germany. As I recall, it was described as being capable of conducting experiments at wind speeds of 1 m/sec even in the middle of winter.