The Net Refrigeration Effect calculator computes the net refrigeration effect based on the enthalpy of the vapor leaving and entering the evaporator.

INSTRUCTIONS: Choose units and enter the following:

• (h_l) This is the enthalpy of the vapor exiting an evaporator
• (h_e) This is the enthalpy of the vapor entering an evaporator

Net Refrigeration Effect (NRE):  The effect is returned in BTUs.  However this can be automatically converted to compatible units via the pull-down menu.

The Math / Science

Net Refrigeration Effect is the quantity of heat that each pound of refrigerant absorbs from the refrigerated space to produce useful cooling.  The formula for net refrigeration effect is:

         NRE = h_l - h_e

where

• NRE = Net Refrigeration Effect (Btu/lb)
• h_l = enthalpy of vapor leaving evaporator (Btu/lb)
• h_e = enthalpy of vapor entering evaporator (Btu/lb)