issue: July 2007 APPLIANCE Magazine
A Roundup of Japanese Air
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by Wasaku Ishida, Japan correspondent, and president, JARN (Japan Air Conditioning, Heating & Refrigeration News)
Sanyo Electric Co. released eight new models of room air conditioners belonging to the “Shikisaikan” (Four Season Pavilion) EX series. To provide higher air quality, the EX series has adopted an “air-wash” function adopted from the drum-type washer/dryer Aqua. This system applies ozone to the air to decompose odorants and bacteria in the indoor unit.
The air-wash function works in two modes. In “block mode” the unit checks the room temperature and humidity to prevent the occurrence of mold or odors in the indoor unit when it is not in operation. In “attack mode,” the CO2 sensor, the simultaneous air supply/exhaust unit, the UV degerming unit, and the electric air purifier work together to purify room air. When the indoor unit is not in operation, it still monitors inside temperature and humidity and initiates the air-wash function as needed to prevent conditions conducive to mold growth. The air-wash function can also be performed manually at the touch of a button.
After 25 minutes of internal drying in block mode, with the front panel and flap closed, a low concentration of ozone is generated from the electric air purifier for 30 minutes, diffusing inside of the unit, after which the residual ozone and decomposed constituents of odors and mold are exhausted by the air supply/exhaust unit. Because of the simultaneous air supply/exhaust function, the attack mode provides smooth ventilation in which inside and outside air pressure are kept the same and room air pollutants are removed quickly.
According to joint research with the Gunma Prefecture Institute for Public Health and Environmental Sciences, the proprietary electrolyzed water technology used by Sanyo Electric in its heating, ventilation, and air-conditioning products is more than 99% effective in suppressing norovirus (feline calicivirus) infectivity. The same technology was also confirmed to inactivate the pathogenic avian influenza and other airborne human influenza, which have been of particular concern in recent years. The company has provided numerous products using its electrolyzed water technology dating back to 1987, when it began sales of cup-type vending machines using the technology. The system utilizes hypochlorous acid, created by electrolyzing tap water and effective at removing bacteria.
Daikin Industries, along with Kazutaka Kano, associate professor at Kobe University Graduate School of Medicine, verified that its streamer discharge technology can decompose viruses. During a test, 10 µl of a solution of noroviruses’ antigen was put into the system microwell and exposed to streamer discharge for 24 hours. More than 96% of the noroviruses’ antigen decomposed. The company established a technology for consistently generating streamer discharge, which is currently being built into its home-use air purifiers, room air conditioners, and commercial deodorizers.
Home-use air purifiers from Daikin feature an evolved version of the streamer discharge, using a newly developed photocatalyst and streamer deodorizing catalyst to decompose three times as much formaldehyde as previous models. Formaldehyde can be a major cause of sick-house syndrome. By discharging streamer mol-ecules from the highest end of the inside stream, the air purifiers can arrest viruses on the prefilter, removing allergens such as pollen.