Solar Water Heater
Solar water heaters sometimes called solar domestic hot water
systems can be a cost-effective way to generate hot water
for your home. They can be used in any climate, and the fuel
they use sunshine is free.
Direct circulation systems
Pumps circulate household water through the collectors and into the home. They work well in climates where it rarely freezes.
Indirect circulation systems
Pumps circulate a non-freezing, heat-transfer fluid through the collectors and a heat exchanger. This heats the water that then flows into the home. They are popular in climates prone to freezing temperatures.
Passive Solar Water Heating Systems
Passive solar water heating systems are typically less expensive than active systems, but they're usually not as efficient. However, passive systems can be more reliable and may last longer. There are two basic types of passive systems:
Integral collector-storage passive systems
These consist of a storage tank covered with a transparent material to allow the sun to heat the water. Water from the tank then flows into the plumbing system. These work best in areas where temperatures rarely fall below freezing. They also work well in households with significant daytime and evening hot-water needs.
Thermosyphon systems
Water is heated in a collector on the roof and then flows through the plumbing system when a hot water faucet is opened. The majority of these systems have a 40 gallon capacity.