Combining PDRCs with other systems may increase their cooling power. When included in a combined thermal insulation, evaporative cooling, and radiative cooling system consisting of "a solar reflector, a water-rich and IR-emitting evaporative layer, and a vapor-permeable, IR-transparent, and solar-reflecting insulation layer," 300% higher ambient cooling power was demonstrated. This could extend the shelf life of food by 40% in humid climates and 200% in dry climates without refrigeration. The system however requires water "re-charges" to maintain its cooling power, with more frequent re-charges in hot climates than cooler climates.