SOLAR HOT WATER HEATING

Tanvee Ghaisas

OBJECTIVES

• What is Solar Hot Water Heating?

• Uses

• Efficiency

What is Solar Hot Water Heating?

• Use Sun’s heat to warm up water in collectors

• 3 types of solar heating:– Passive solar heating– Active solar heating– Solar collectors

Passive Solar Heating

• Solar collector heats water; storage tank heats water

• Two types of passive solar heating– Batch heaters– Thermosiphon systems

Active Solar Heating

• Heated water moved through system with aid of pumps; this increases the system’s efficiency

• Two types of active solar heating– Direct systems– Indirect systems

Solar Collectors

Flat-plate collectors are used for residential water-heating and space-heating installations

Uses of Solar Hot Water Heating

• Swimming pools

• Household uses:– Cooking– Plumbing– Sanitary needs– Cleaning– Heating

Efficiency of Solar Hot Water Heating

• Energy is required to heat water– There is heat loss– System not 100% efficient

Example: to heat 100 liters of water from 20ºC to 60ºC

E= mcΔt

E= (100l)(4.2J/lºC)(40ºC)

E= 16.8MJ

Therefore, 16.8MJ of energy is required only to heat the water. Electricity can be used to heat water, but it tends to be expensive and unavailable in some areas.

References

• http://www.itdg.org/docs/technical_information_service/solar_water_heating.pdf

• http://www.eere.energy.gov/solar/sh_basics.html