Subject:- Refrigeration and Air Conditioning

Topic:- Duct Design, Controls & Applications

Difficulty:- Medium

Sea water air conditioning (SWAC) takes advantage of available cold deep seawater to replace energy-intensive central refrigeration systems in one or more buildings.

The system consists of cold seawater supply line, a heat exchanger (at shoreline), and a closed cycle fresh water distribution system.

Cold seawater is drawn from 600 m deep at 7°C temperature. It follows a pipeline that lies along seabed, 500 m from shore. This water is delivered to the heat exchanger by pump station. This results in heat exchange with the closed fresh water system and the fresh water becomes chilled which is distributed to the buildings to condition the air.

The seawater is then pumped back to the sea through an effluent pipe at 200 m depth to avoid biological impact of thermal heat on marine life called ‘Cold Shock’.

The benefits of SWAC are:

i. Large energy savings reaching upto 90%

ii. Short economic payback period

iii. No evaporative water consumption.