Heat Pipe Design  Capillary Limits The capillary limit is also dependent on the heat pipe dianeter,length pipe diameter, length, and orientation.Larger wick crosss- sections for fluid flow and larger vapor space cross-sections for vapor flow ,which reduce frictional losses resulting from the fluid and  vapor flow,respectively.As a result,larger diameter heat pipes will transport more power than	smaller diameter heat pipes.Longer shows the capillary limit as a function heat pipes will have larger frictional of temperature for a variety of heat  losses as the fluid flows through pipe diameters and a horizontal the wick structure and will transport  orientation.For the same heat pipe, less power than shorter heat pipes. Chart Dnshows the capillary heat pipes operating in a gravity- limit as a function of temperature aided orientation will transport more  for various heat pipe diameters and  power than heat pipes in a horizontal a vertical,gravity-aided orientation. orientation.Likewise a heat pipe in a  Chart E shows the capillary horizontal orientation will transport  limit as a function of temperature for more power than a heat pipe in an  a variety of heat pipe lengths and a against-gravity orientation.Chart C horizontal orientation.
Chart C: Capillary Limit as Function of Temperature and Heat Pipe Diameter (Horizontal Orientation)