Do It Yourself Solar Hot Water

Using solar energy for domestic water heating is one of the most cost-effective ways to reduce your power bill and the carbon footprint of a household. 

Either evacuated tubes or flat plate collectors can be used for diy solar hot water. A conventional boiler or immersion heater can be used to produce hot water for those occasions when the sun does not oblige, which is often necessary for night-heating or in countries where sun exposure is weak in winter. 

The type of system chosen depends firstly on whether freezing is likely to occur. In climates where freezing is not a problem, there are three main options:

• A batch heater
• A direct pump system
• Or a thermosiphon system

A batch heater employs a storage tank for collection; a direct pump system moves water from a collector to a storage tank; and a thermosiphon system uses gravity, and no pump. 

If temperatures are low enough to cause freezing, then drainback or closed loop systems with heat exchangers and antifreeze will be required. 

Drainback systems use distilled water to transfer heat, while closed loop systems circulate antifreeze and use a heat exchanger to transmit the heat to prevent freezing.