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                    310                                                    Lawrence K. Wang et al.

                    Table 1
                    Coolant Selection
                    Required condensation                                        b Coolant inlet
                               a
                    temperature, T  (ºF)                Coolant               temperature, T  (ºF)
                                 con                                                     cool,i
                    c T  : 60–80           Water                                   T   − 15
                      con                                                            con
                    60 > T  > 45           Chilled water                           T   − 15
                          con                                                        con
                    45 >T   ≥−30           Brine solutions (e.g., calcium chloride,   T  − 15
                         con                                                         con
                                             Ethylene glycol)
                    −30 > T  ≥−90          Chlorofluorocarbons (e.g., Freon-12)    T   − 15
                           con                                                       con
                       a Also emission stream outlet temperature.
                       b Assume the approach as 15ºF.
                       c Summer limit.
                       Source: ref. 4.


                    and the condenser’s removal efficiency. Dehumidification eliminates icing by using a
                    heat exchanger to cool the vapor to about 35ºF, prior to the condenser. Even with dehu-
                    midification, water vapor can remain a problem for subzero condensation systems,
                    requiring provisions such as dual condensers, in which heated air melts ice from the
                    off-line condenser (12).







































                                  Fig. 3. Example of condenser performance. (From US EPA.)
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