Guide to the Different Types of Solar Water Heater Systems

Solar water-heating systems directly substitute renewable energy for conventional energy, lowering the need for electricity or fossil fuels by as much as 80 percent. Solar water heating systems nowadays have proven to be dependable when appropriately matched to climate and load. There are only a few manufacturers and installers on the market today who can provide reliable equipment and good system design. Despite the fact that there are many different types of solar water heating systems, the underlying technology is relatively straightforward.

Quality certification and performance-rating schemes for solar water-heating systems were formed by a voluntary coalition of the solar industry and various consumer organizations, making it easy to buy reliable equipment with confidence. To save energy, building owners could look into installing solar hot water systems. Prior to installing a solar system, however, water-use reduction methods should be implemented.

  • Thermosiphon Systems

These devices heat water or glycol-based antifreeze fluid. The fluid is transported from the collectors to the elevated storage tank by natural convection. Pumps are not necessary. In thermosiphon systems, fluid velocity and thus heat transmission rises with temperature, so these systems work best in areas with a lot of sunlight.

  • Direct-Circulation Systems

During the day, these systems transfer water from storage to collectors. By cycling hot water from the storage tank or flushing the collectors, freeze protection can be achieved. Direct-circulation systems are only utilized in places where freezing temperatures are uncommon since the recirculation system uses more energy while flushing reduces the number of hours of operation.

  • Drain-Down Systems

Indirect water heating is used in the majority of these systems. A heat exchanger transfers heat from treated or untreated water to drinkable water in a closed-loop system. When there is no solar heat available, gravity drains the collection fluid to prevent freezing and convection loops in which cool collector water lowers the temperature of the stored water.

  • Indirect Water-Heating Systems

A freeze-protected fluid is circulated via a closed-loop in these systems, and its heat is converted to potable water via a heat exchanger with an efficiency of 80 to 90 percent. Water-ethylene glycol solutions and water-propylene glycol solutions are the most often utilized fluids for freeze prevention.

  • Air Systems

The collectors in this indirect system heat the air, which is then transported through an air-to-water heat exchanger by a fan. The water is then used for household or service reasons. The heat exchanger’s efficiency is around 50 percent.

Direct-circulation, thermosiphon, and pump-activated systems demand additional maintenance in cold temperatures. Indirect air and water systems are the most suitable for much of Australia. While not as efficient as water solar systems, air solar systems should be considered if maintenance is a top priority because they do not leak or burst.

Back To Top