Transient Analysis of Snow-Melting System Performance

The transient response of snow melting systems for pavements, by virtue of their thermal mass and the fact that they are operated intermittently, has a significant effect on overall system performance. Traditional steady-state methods of snow melting system load calculation have not been able to take into account the thermal history of the system or the transient nature of storm weather. This paper reports on the work of a recent ASHRAE-sponsored project that has sought to assess the significance of these effects on system performance. The development of a numerical transient analysis method that includes a boundary condition model able to deal with melting snow conditions is described. This numerical method has been incorporated into a transient analysis tool that can be used by practitioners to examine transient effects on system performance. The results of a parametric study that examined transient effects using real storm event data are presented. Effects of storm structure were found to be most significant. Calculations of back and edge losses under transient conditions are also presented.