S39 -- Condensers (SI)

The condenser in a refrigeration system is a heat exchanger that rejects all the heat from the system. This heat consists of heat absorbed by the evaporator plus the heat from the energy input to the compressor. The compressor discharges hot, high-pressure refrigerant gas into the condenser, which rejects heat from the gas to some cooler medium. Thus, the cool refrigerant condenses back to the liquid state and drains from the condenser to continue in the refrigeration cycle. Condensers may be classified by their cooling medium as (l) water-cooled, (2) air-cooled, (3) evaporative (air- and water-cooled), and (4) refrigerant-cooled (cascade systems). The first three types are discussed in this chapter; see Chapter 48 in the 2022 ASHRAE Handbook -- Refrigeration for a discussion of cascade-cooled condensers. WATER-COOLED CONDENSERS Heat Removal Heat Transfer Water Pressure Drop Liquid Subcooling Water Circuiting Types Noncondensable Gases Testing and Rating Operation and Maintenance AIR-COOLED CONDENSERS Types Fans and Air Requirements Heat Transfer and Pressure Drop Condensers Remote from Compressor Condensers as Part of Condensing Unit Water-Cooled Versus Air-Cooled Condensing Testing and Rating Control Installation and Maintenance EVAPORATIVE CONDENSERS Heat Transfer Condenser Configuration Condenser Location Multiple-Condenser Installations Ratings Desuperheating Coils Refrigerant Liquid Subcoolers Multicircuit Condensers and Coolers Water Treatment Water Consumption Capacity Modulation Purging Maintenance Testing and Rating