There are two key factors affect the performance of a reverse osmosis membrane and should always be considered when evaluating the system.  The temperature of the feedwater and the net driving pressure across the element both indicate whether the system or the membrane is in optimum operating condition or needs replacement.  Use the information below to calculate the affects of these two factors.

Temperature Correction Factor
Temperature has an inverse affect on product flow through the membrane; a high temperature increases product flow, a low temperature decreases product flow. All reverse osmosis membranes and systems are rated at 25ºC (77ºF).  To find the membrane permeate rate at another temperature, folloe these steps:

• Find the temperature correction factor (TCF).
  
• Divide the rated permeate flow by the TCF. The result is the permeate flow at the desired temperature.