Panasonic's "Green Air Conditioner" mixes air and ultra-fine mist and sprays it. Photo: Nikkei xTech

Air conditioner sprays ultra-fine mist for cooling at train station in Tokyo

By Norio Matsumoto

Panasonic Corp has installed a "Green Air Conditioner," which cools ambient air by using mist with an average particle size of 10μm, at Shimbashi SL Square at Shimbashi Station.

With one unit, about 15 people can cool off, the company said.

The Green Air Conditioner mixes (1) ultra-fine mist called "Silky Fan Mist" and (2) compressed air and sprays it. As a result, water drops are attached to human body surfaces. When the water drops are vaporizing, they lower the body temperature, realizing a "pseudo perspiration effect."

Moreover, the size of the water drops is 1/2 to 1/3 that of common mist. So, the water drops easily evaporate and have the "evaporative cooling effect," which draws heat from air and cools the space.

By combining the pseudo perspiration effect and evaporative cooling effect, in a sun-heated outdoor space with a temperature of 40° C, it is about twice as efficient as common air conditioners using heat pumps, Panasonic said.

To mix air and water in an optimal condition, the "two-fluid mist nozzle," a structure developed by Panasonic, was employed. Moreover, by using a tornado-type air flow, it became possible to spray mist in a wider area, enabling the air conditioner to cool about 15 people.

The control part of the Green Air Conditioner has a communication function. It can obtain weather information via the internet and use it for control, remote monitoring, etc.

In recent years, due to heat island phenomenon, the average temperature of urban areas rose by 2-3° C in the past 100 years. As a result, health problems such as heatstroke and impacts on economic activities became issues. At the Tokyo Olympic/Paralympic Games, which will take place in 2020, high-temperature, high-humidity summer in Japan is expected to be a problem for athletes and spectators.

Panasonic plans to release the Green Air Conditioner in September. The reference price of the product is about ¥1.5 million, excluding an installation cost.

The Green Air Conditioner Flex consists of a (1) device box housing a control part and driving part and (2) nozzle unit for spraying mist. It enables to use plastic pipes, which can be relatively freely placed, and can be installed for existing structures, Panasonic said. It is targeted at public facilities such as stadiums.

© Nikkei x Tech

©2020 GPlusMedia Inc.

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As the average global temperature climbs, how are we going to cope? Will we cope?

2 ( +2 / -0 )

Does it increase humidity, which is the main complaint about the Japanese summer?

3 ( +3 / -0 )

How long can those nozzles last before salt crystals start building up.

2 ( +2 / -0 )


As the average global temperature climbs, how are we going to cope? Will we cope?

If this keeps up we'll probably all end up stuck in our houses with special AC units turned on permanently, in a couple decades from now. As for survival... We'll probably be wearing Mass Effect-style suit/armor.

2 ( +2 / -0 )

the problem with mist cooling is that it adds to the humidity. there are new desiccant ( water removal materials) technologies that dont use the state change refrigerant technology. it is being developed by Germany.

2 ( +2 / -0 )

The reference price of the product is about ¥1.5 million

I think any engineer could make the same thing on a smaller scale for 100 000 yen.

1 ( +1 / -0 )

We need to reduce the amount of green house gases being put into the air, quickly. CO2 has a half life in the atmosphere of about 100 years, so the future is going to get hotter, even if we were to somehow stop putting all man-made CO2 into the air today.

-1 ( +0 / -1 )

If I recall, the middle east was once a grassland that harboured much life. It desertified and dried, yet people still live there. Because their granddaddy ad nauseum lived there. Maybe Japan and the world will look just like Egypt or Saudi Arabia today - a few green strips around rivers and oceans with interior brown.

0 ( +0 / -0 )

It's just going to add to the humidity.

0 ( +0 / -0 )

Old technology and not worthy of news. Mist cooling systems have been around for decades and used in restaurants, bars and home patios where there is high heat and low humidity as a means to cool an area.

0 ( +0 / -0 )

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