There are two different types of solar water heaters: passive and active. Both rely on sunlight to warm the water in your house, but what distinguishes the two is the way the water is transferred toward the sunlight.
Active systems rely on a pump to manually transfer the water to the roof or solar collector, whereas a passive system doesn’t. In this guide, we’ll be talking passive solar water heaters. All Solar water heating systems have two basic components. These components include an insulated storage tank and a solar collector.
A solar collector is a device in which the water is transferred to and heated by sunlight. Solar collectors come in a number of varieties; however, all of them absorb the energy from sunlight and transfer that energy to the water or a different heating medium. After the water is heated, it has to be stored until it’s used.
A Solar Water Heater (which is also known as “เครื่องทำน้ำร้อนพลังงานแสงอาทิตย์” in the Thai language) is most frequently used. This tank closely resembles a tank type water heater and performs a number of the very same functions.
Passive solar water heaters are less efficient than the typical active solar water heater. But what a passive solar heating system lacks in efficiency it makes up for it in reliability and long life. Passive heaters are typically less expensive than an active system also.
Passive solar water heaters come in two varieties: integral collector storage (ICS), and thermosiphon (occasionally spelled “thermosyphon”) systems.
Integral collector-storage systems maintain the water storage tank located below the solar collector. Cold water flows to the solar collector, where it’s heated by sunlight, then drawn down to the storage tank beneath. Integral collector methods work best in areas where the outside temperature rarely falls below freezing.
The second kind of passive solar water heating system is the thermostatic type. Compared to integral collector storage systems, thermostatic systems maintain the storage tank situated above the solar collector.