A condenser is a device that is used to liquefy gas by cooling it. In HVAC equipment, hot discharge gas (refrigerant vapor) from the compressor enters the condenser coils at the top and is condensed, drains out of the condenser to a receiver located near the bottom. The condenser coil is located along with the compressor and controlling devices in the condensing unit. In a remote or split system air conditioning installation, the condensing unit is located outdoors. Condensers are available in a variety of sizes and designs that include plain tube, finned tube and plate type, series-pass and parallel pass units.
Condensers are classified by their cooling method. The three main types are broken down to:
- Air-cooled condensers
- Combined air and water-cooled condensers
- Water-cooled condensers
An air-cooled condenser consists of a coil of ample surface that air is blown by a fan or induced by natural draft. This type of condenser is universally used in small capacity refrigerating units. Mostly designed for residential or small office air conditioners.
Air-chilled condensers should be kept from free from dirt, lint and other foreign materials because they tend to reduce the airflow around the tubes and fins if they are allowed to accumulate just like evaporators.
Combined Air- and Water-cooled Condensers
This type of condenser is also know as an evaporative condenser and consists of a coil cooled by water sprayed from above and then cold air enters from the bottom and is blown across the coils. As water evaporates from the coil it creates a cooling effect that condenses the refrigerant within the coil. The refrigerant gas in the coil is hot which changed to the liquid state by combining the sprayed water and the large column of moving air supplied by the fan. The water that does not evaporate is recirculated by means of a pump.
A water-cooled condenser is similar to a steam surface condenser in that cooling is accomplished by water alone that circulates through tubes or coils enclosed in a shell. IN a water-cooled condenser the refrigerant circulates through the annular space between the tubes or coils. Because of its construction, a water-cooled condenser is also referred to as a double-pipe condenser.
Because an evaporative condenser is not wasteful of water, large compressor installations are possible in areas where water is scarce. Tests have shown that the amount of water required will not exceed the.03 gpm per ton of refrigeration. This is one of the eco-friendly reasons to use this type of condenser. Evaporative condensers also eliminate water water disposal problems and provide the most economical means of cooling refrigerant gases of standard air conditioners.