External HDD case 'Drivedoor TeraBox' that can contain up to 4 3.5-inch HDDs

I bought an external 3.5-inch hard disk case, but it was so hot that I was sick. After all fans may be necessary ... I was worried, so when I measured it with a non-contact thermometer, it was about 42 degrees ... I thought it was hotter ...

HDD case 'Drivedoor TeraBox' that can contain 4 HDDs for Century-ITmedia PC USER
https://www.itmedia.co.jp/pcupdate/articles/0507/08/news035.html

Hard disk case: Drivedoor Terra BOX: EX35SW4 / EX35SB4
http://www.century.co.jp/products/suto/ex35sw4b4.html

Like this

The front is openable, and you can insert the HDD like this

The price seems to be around 20,000 yen ... To make it 1TB, you have to install 4 250GB units ...

But that would be cheaper ...

RAID Hard Disk | RAID Compatible Hard Disk TeraStation
http://buffalo.melcoinc.co.jp/products/catalog/storage/terastation/

Hard Disk | HD-HTGL / R5 Series
http://buffalo.melcoinc.co.jp/products/catalog/item/h/hd-htgl_r5/

What should I do……