Description

A number of design variables can come into play when selecting and designing a process cooling system. The following formula commonly is applied. Q (BTUs) = W x Specific Heat x gT Where W is the weight of material to be cooled. Specific Heat is a heat constant taken from tables. gT is the initial temperature minus final desired temperature. Note that 1 ton of refrigeration is 12,000 BTU/hr. The amount of time required to cool the process also must be considered. In the above example, if the corn syrup was allowed one hour to cool, you would need 19,635 BTUs per hour of chiller capacity for more than one hour. Divide the heat load by the amount of time (in hours) to discover the hourly heat removal rate. Typically, 10 to 15% safety factor is added for losses that may occur from piping or uninstalled surfaces.