Disclosed is a transport refrigeration unit (TRU) having: an engine configured to power a refrigeration system of the TRU, the engine including an air intake, the engine within an engine compartment of the TRU; an air management valve (AMV) fluidly coupled to the air intake; a first duct fluidly coupled to the AMV and including a first inlet within the engine compartment; and a second duct fluidly coupled to the AMV and including a second inlet that is exterior to the engine compartment and is configured to receive atmospheric air; wherein: the AMV is configured to modulate air into the engine from the first duct and the second duct, when a temperature of air within the AMV is above the first threshold and the temperature of air within the second duct is below the first threshold, to lower the temperature of air entering the engine to below the first threshold.