Editing Refrigeration (section)

===Passive systems===
When combining a [[passive daytime radiative cooling]] system with [[thermal insulation]] and [[Evaporative cooler|evaporative cooling]], one study found a 300% increase in ambient cooling power when compared to a stand-alone radiative cooling surface, which could extend the [[shelf life]] of food by 40% in [[Humidity|humid climates]] and 200% in [[Desert climate|desert climates]] without refrigeration. The system's evaporative cooling layer would require water "re-charges" every 10 days to a month in humid areas and every 4 days in hot and dry areas.<ref>{{Cite journal |last1=Lu |first1=Zhengmao |last2=Leroy |first2=Arny |last3=Zhang |first3=Lenan |last4=Patel |first4=Jatin J. |last5=Wang |first5=Evelyn N. |last6=Grossman |first6=Jeffrey C. |date=September 2022 |title=Significantly enhanced sub-ambient passive cooling enabled by evaporation, radiation, and insulation |journal=Cell Reports Physical Science |volume=3 |issue=10 |page=101068 |doi=10.1016/j.xcrp.2022.101068 |bibcode=2022CRPS....301068L |s2cid=252411940 |doi-access=free |hdl=1721.1/146578 |hdl-access=free }}</ref>