
Parameter  Description  Unit 

 Temperature of the fluid entering the system  K 
 Temperature of the fluid leaving the system  K 
 Mass flow rate of the fluid  kg s^{1} 
 Specific heat capacity of the fluid at constant pressure  kJ kg^{1}K^{1} 
 Inner diameter of the heat exchanger pipe  m 
 Outer diameter of the heat exchanger pipe  m 
 Thermal conductivity value of the pipe wall material  W m^{1}K^{1} 
 Heat transfer coefficient of air  W m^{2}K^{1} 
 Heat transfer coefficient of water  W m^{2}K^{1} 
 Surface area of the heat exchanger wall  m^{2} 
