Types of Solar Water Heaters

Solar water heaters are made from systems made from many mature renewable energy (Solar hot water) technologies and several innovations. Residential solar water heaters are designed to supply the optimum amount of a household’s hot water requirements for most of the year. However during winter an electric or gas booster is sometimes required because there may not be sufficient heat gain to deliver enough hot water.

The size, type and complexity of solar water heaters is mostly determined by:

1. The water and temperature requirements of the system.
2. Ambient temperature changes cause between summer and winter.
3. Ambient temperature changes caused the day and night cycle and
4. The chances collector fluid or portable water overheating or freezing.

There are several types of solar water heating systems namely: indirect or closed SHW systems direct or pump circulated SHW systems, passive SHW systems and active SHW systems.

In indirect or “closed coupled” solar hot water systems or SHW systems, the solar collectors are placed on the roof and have the storage tank mounted horizontally above it. Hot water naturally rises up in to the tank by means of thermo-siphon flow meaning no plumbing is required.

In a direct or “pump circulated” SHW system the collectors are found above the storage tank with the storage tank being floor or ground mounted. In this case hot water movement between the tank and collectors is achieved by means of a circulating pump.

Passive SHW systems depend on heat pipes or heat driven conventions to circulate water in the system. Passive solar water heaters are generally less expensive as compared to active SHW systems and have very low or no maintenance requirements. However the down side is that passive SHW systems are less efficient than active SHW systems with the systems chances of freezing or overheating being concern.

Active SHW systems on the other hand use more than one pump to circulate water, are more efficient and offer much more advantage than passive SHW systems. Though they are slightly more expensive than their counterparts they are well worth the cost due to their added benefits. Understanding your hot water needs helps in assisting you identify the best solar water heaters to select for your needs.