| Heat load:
The amount of heat to be rejected or injected by the heat exchanger [BTU/Hr]. |
| Ambient
temperature: The temperature surrounding the heat exchanger [degrees ° F] |
| Flow rate:
The rate of liquid or gas flow [lbs./hr] |
| Specific gravity:
The weight of a fluid compared to the weight of water. [Fluid lbs./cu.ft. / 62.4] |
| Specific heat:
The heat constant for a liquid or gas at a given temperature [BTU/LB ° F] |
| Thermal conductivity: |
| Leaving
temperature Differential (LTD): Difference between the process leaving
temperature minus the coolant entering temperature. (T2 – t1) |
| -T1:
Entering temperature (° F) of the hot process fluid |
| -T2:
Exiting temperature (° F) of the hot process fluid. |
| -t1: Entering
temperature (° F) of the cold fluid. |
| -t2: Exiting
temperature (° F) of the cold fluid. |
| CN:
Constant number correction for fluid to simplify the basic heat transfer conversion. |
 P: The
differential pressure (PSIG) across the heat exchanger from inlet to outlet. |
| T & t:
Temperature differential (° F) from inlet to outlet respective. |