(DSWH) Domestic Solar Water Heating System


1. Passive Domestic Solar Water Heating Systems:

  • Characteristics:
    • Reliability and Easy Maintenance: Passive systems utilize gravity and natural circulation of water, eliminating the need for electric pumps. They are generally more reliable and easier to maintain.
  • Types:
    • Batch Heater:
      • Description: Simplest solar hot water system with a tank of water within a glass-covered insulated enclosure aimed at the sun.
      • Operation: Water within the tank is heated directly by solar radiation.
      • Application: Commonly used for residential water heating.
    • Thermosyphon System:
      • Features:
        • Natural circulation of water.
        • Flat plate collector.
        • Collector placed below the storage tank.
        • Hot water is taken from the top of the tank.
      • Operation: Solar-heated water naturally rises through the collector and into the storage tank due to the density difference, creating a self-sustaining circulation.
      • Application: Suitable for residential water heating.

2. Active Domestic Solar Water Heating Systems:

  • Characteristics:
    • Use of Electric Pumps: Active systems use electric pumps, valves, and controllers to circulate water or heat transfer fluids through the collectors.
  • Types:
    • Direct Active System:
      • Description: The fluid circulating through the collector is also the fluid used for domestic water heating.
      • Application: Commonly used in regions with mild climates.
    • Indirect Active System:
      • Description: A heat transfer fluid circulates through the collector and transfers heat to the domestic water through a heat exchanger.
      • Application: Suitable for colder climates where freezing conditions may occur.

The choice between passive and active DSWH systems depends on factors such as climate, energy requirements, and maintenance considerations.