Table 2.

Controlled and variable parameters

	The tubes were arranged in a staggered
	Operating temperature of 60,70 and 80°C
The controlled parameters	Silver nanofluid concentration of 0.5 w/v%
	Volumetric flow rate was 5 l/min in evaporator section
	Cool water flow was 25°C in condenser section
	Working fluid = pure water, silver nanofluid concentration of 0.5 w/v% and silver nanofluid concentration of 0.5 w/v% mixed oleic acid surfactant
The variable parameters	Concentration of oleic acid surfactant were 0.5, 1, 1.5 w/v%
	Volumetric flow rate were 1, 2, 5 l/min in condenser section
	Filling ratio = 30, 50, and 80% (by total length of evaporator)