YOU SAID:

It needs to be 20 percent cooler

INTO JAPANESE

20% 冷やす必要があります

BACK INTO ENGLISH

Need to cool 20%

INTO JAPANESE

20% 冷却する必要があります

BACK INTO ENGLISH

Must be cooled by 20%

INTO JAPANESE

20% 冷却する必要があります

BACK INTO ENGLISH

Must be cooled by 20%