Recently,I read the news about the zero air cooler,which is made with re-purposed plastic bottles.And the new claims that it helps reduce indoor temperature by 5 degrees centigrade.
The making process is shown as following:

I dout that very much.

the Joule-Thomson Coefficient for air (mostly nitrogen) at 300K (27?C/80?F) is about 0.36K/bar. This means that at 300K a 1bar change in pressure equates to a 0.22K. The change in pressure required to get the 5?C (5K) reduction would therefore be:

5 / 0.22 = 22.7bar

So I think it is impossible the temperature drop will be up to 5 degrees centigrade after the air through the bottle.

What do you think?

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Yongqing Zhao
Changsha Green Building & Energy Saving Technology CO.,LTD
NO.438,Shaoshan Road,Changsha,Hunan,China
Telephone:13574805636
Email:zhaoyongqing1987 at 126.com
503271081 at qq.com