image of a solar powered water heater

How Solar Water Heaters Work

solar hot water heaterAlso referred to as solar domestic hot water systems, a solar water heater is undoubtedly the most efficient of all methods of heating in a domestic or residential setting. This cost-effective home heating strategy is ideal not only because it literally does not need the purchase of any kind of fuel for heating, but because there is very little or minimal operational cost. The fuel used in a solar water heater is sunshine, which obviously is a sustainable and infinite commodity.

How A Solar Water Heater Works

A typical solar water heating system utilizes two important components – storage tank and solar collectors. But more importantly, solar water heating systems are classified into two different types; the first one being the active solar water heater and the second one is the passive system. The former takes advantage of a sophisticated set of parts, including circulating pumps and controls. The passive system, on the other hand, does not have those parts.
As for the active solar water heating system, the variants are divided into two: direct circulation systems and indirect circulation systems. Direct circulation systems use pumps in order to circulate household water through the collectors and distributed to the different parts of the home. Direct circulation systems have limited compatibility since they only are recommended in climates where freezing temperatures are uncommon.

image of a solar powered water heaterIndirect circulation systems on the other hand use pumps in circulating a heat-transfer and non-freezing fluid via the collectors and through a heat exchanger. The system heats the water before it is distributed into the home. In contrast to a direct circulation system, this one is best used in areas known for their freezing temperatures.
Meanwhile, passive solar water heating systems are preferred over active systems for the reason that they are more affordable to install. However, the long-term costs could be detrimental since they are also known to be inefficient. Nonetheless, they are known to last longer than active systems and are more reliable when it comes to function. Just like active solar water heating systems, there are two different types of passive systems. These are the integral collector-storage passive system and the thermosyphon system. The first type is ideally installed in temperatures that don’t normally fall below the freezing point. Furthermore, they also are best used in homes that experience a lot of daytime and night-time hot water needs.

On the other hand, thermosyphon systems work by way of water flowing through the system once warm water rises and cooler water sinks. A collector is installed below the storage tank so as for the warm water to rise into the tank. A thermosyphon system is known for its reliability, although there is a need to figure out if the roofing design of the home is ideal for it. The reason is that this system incorporates a particularly heavy storage tank. Also, be reminded that a thermosyphon system is, for the most part, pricier than the integral collector-storage passive system.
Majority of solar water heaters need a storage tank that is well-insulated. These tanks are equipped with added outlet and inlet, both of which are used for connection to the collector. For a two-tank setup, the solar water heater works by pre-heating the water before it reaches the traditional water heater. On the other hand, the one-tank system works in such a way that the backup heater is integrated with the solar storage in a single tank.


Finally, if you are planning to buy and install a new solar water heater for a residential application, there are some important things you must do first. For example, you need to come up with an estimate of the cost as well as energy efficiency of the model. Also, it is important that you first figure out if the solar resource in your location is good enough. If you live in a place where the sun does not shine for the most part of the year, a solar water heater may not be a practical solution. Finally, learn what local codes and regulations apply to the installation of equipment like a solar water heater.