The Basics


Solar water heaters rely on the sun to heat the water provided to your home or building. These systems are reliable and relatively straightforward. At the core, a solar water heater is reliant on the solar collector and storage tank. The collector is an insulated box, usually with a dark interior, that contains tubes that allow for water flow. The solar collector catches the sun's rays and transforms them into heat. The storage tank simply holds the heated water. From here, the functionality of the solar water heater depends on the type.


●        Passive System

Of the passive system designs, there are both Batch and Thermosiphon designs available. The Batch design is quite simple and contains a water tank directly inside the solar collector. The water is heated through the solar collector and natural convection (hot water rises), hot water is pumped through the pipes and into the building. In a Thermosiphon design, the storage tank is separate from the solar collector. Cold water runs through the pipes in the collector where the water then becomes hot. The hot water, through natural convection, is moved to the separate water tank and then plumbed into the building.


●        Active System

Typically, active systems are better for areas where temperatures drop below freezing. There are three main types of active systems. In Direct systems, water is moved from the solar collector to the tank via pumps. In Indirect systems, the water is never directly heated by the solar collector but by a fluid, such as antifreeze, which resides in sealed pipes. The antifreeze is heated and pumped through piping which indirectly heats the water in the storage tank. Thirdly there is a Drainback design. This design is very similar to an Indirect system with the exception that distilled water is used in place of a heat-transfer liquid.




Both traditional gas and electric water heaters use a great deal of energy and release carbon emissions to the environment. Installing a solar water heater is a great green alternative. Most solar water heaters do require the use of a backup traditional heater in high demand times or when the weather is forecast to be cloudy or rainy. In general, a solar water heater can reduce energy bills and carbon emissions by nearly 50 percent. In places like Arizona with constant sunshine, owners report a nearly 90 percent drop in energy bills. To improve the efficiency of the system consider the orientation of the solar collector. More exposure to direct sunlight means more ability to generate heat to transfer to your water.


At Gausman & Moore, we are passionate about sustainable design. Our engineers are creative and dedicated to finding solutions to your toughest problems. If you are interested in learning more about solar energy or renewable energy designs, contact us today. You will be able to see our past projects and get an understanding of the services we offer.