It is one of the unit used to measure the water volumetric flow rate.
The stand formula for calculating the TR as follow,
TR = (GPM × Delta T)/24
For this,we can find out the GPM
GPM =( TR×24)/Delta T
Where GPM is flow rate
TR is ton of Refrigeration
Delta T is temperature difference between supply and return chilled water
Let us consider AHU and its inlet and outlet water temperature is 30 degrees fahrenheit and 38 degrees fahrenheit and TR is 10.
Apply all these values in the GPM formula
GPM = (10×24)/(38-30)
= 240/8
GPM=30
Here the GPM depends only on temperatures, as the TR is constant throughout the process.
