Solar Water Heating Systems

Solar Water Heating (SWH) systems convert sunlight into heat for water heating using solar thermal collectors. These systems are available in various configurations to suit different climates and applications, ranging from residential to industrial use.

Operation Principles

Thermosyphon Principle: Relies on natural convection to circulate water.
Force Flow Principle: Uses pumps to circulate water.

Main Components

Flat Plate Collectors: Enclosed in a glass-faced box, they absorb solar energy to heat water.
Insulated Tank: Stores hot water, maintaining temperature.
Plumbing: Connects the system components.

System Capacity

Industrial systems range from 500 liters per day (LPD) to 20,000 LPD.

Collector Types

Flat Plate Collectors:

Design: Consist of horizontal and vertical pipes (headers and risers) with absorber fins.
Operation: Heat-transfer fluid circulates through the pipes, collecting heat and transferring it to the storage tank.
Variations: Serpentine collectors use a single pipe but are unsuitable for drain-back systems due to drainage issues.

Evacuated Tube Collectors (ETC):

Design: Consist of concentric glass tubes with a vacuum in between, minimizing heat loss.
Efficiency: The vacuum acts as an insulator, making ETCs highly efficient.
Durability: Vacuum life ranges from 5 to 15 years.