Condensers: Cooling Towers

 Types of Water Systems:

1. Wastewater Systems:

   • Uses city or municipal water, which is passed through the condenser and then drained.
   • Limitations: Due to water use restrictions and conservation, these systems are less common.
   • Alternative Sources: Some systems use rivers, lakes, or aquifers to supply and discharge water.
   • Water Usage: Approximately 1.5 gallons per minute per ton of capacity (based on 75°F water).

2. Recirculating Systems (Cooling Towers):

   • Water Usage: Circulates about 3 gallons per minute per ton (based on 85°F water).
   • Efficiency: Recaptures a large portion of the water.

   Types of Cooling Towers:

   • Induced Draft Cooling Tower:

     • A fan at the air outlet pulls air through the tower.
     • Causes water to evaporate, absorbing heat and conserving water.
     • Example: Air enters on the right side and discharges at the top, water trickles down through slats, and a portion evaporates.

   • Forced Draft Cooling Tower:

     • A fan or blower pushes air through the tower.
     • Example: Air enters at the rear of the fan housings and is pushed across.

   • Evaporative Condenser:

     • The condenser coil is located within the tower.
     • Water is sprayed over the coil, causing evaporation and heat absorption from the refrigerant.
     • Example: Water and refrigerant flow are managed within the tower to desuperheat, condense, and subcool the refrigerant.

Condensing Units:

• Design: Combines the condenser and compressor into one component.
• Components: May include a liquid receiver, filter dryer, pressure controls, and head pressure regulation.
• Example:
  • Components: Liquid receiver, crankcase heater, control box, suction line, suction service valve, discharge line, head pressure regulating valve, liquid line, liquid service valve, sight glass, and filter dryer.
  • Installation: Typically placed on rooftops, with condenser coils and compressors housed within a cabinet.

Examples:

• Residential Condensing Unit: High efficiency heat pump.
• Walk-In Cooler: Top-mounted condensing unit with all components contained within a cabinet on the roof or top of the cooler.