What are types of solar water heaters?
Solar water heaters are divided into two broad categories. These are; collector-based and heat pumps. This can also be a passive solar water heater vs an active solar water heater
1. Collector based solar water heaters.
The collector-based solar water heaters are
- -Flat plate collector
- -Evacuated tube collector
- -Heat pump solar water heaters
Flat plate collectors
These are the types of solar water heating systems that are mainly used for domestic use. A typical flat-plate collector comprises of an insulated box and a dark absorber plate.
The insulation prevents heat from escaping from the plate. The absorber is designed to tap maximum heat that will be responsible for raising the temperature of the water.
Evacuated tube collectors
These collectors are characterized by rows of transparent glass tubes which are positioned to be in parallel to each other.
Each tube has an absorber that absorbs the heat from the sun. The absorber can be a metal that has a fin designed to absorb solar energy.
Integral Collector Storage Systems
These ones are usually referred to as batch solar water heating systems. In terms of this solar water heater design, this one features a glazed box with several tubes.
The collector receives water then preheats it. This water is then transferred to the backup heating unit.
This type of solar water heater is usually used in areas that experience prolonged temperatures.
2. Heat pump systems
Heat pump solar water heaters have the same working mechanism as air conditioners. The wok by collecting the solar heat from the surrounding air and direct it to the target zone.
This means that they do not have the solar collectors to do the heating job.
The heat pump systems are also referred to as active solar water heaters. This is because they continuously absorb the heat.
The pumps circulate operate by circulating a non-freeze heat fluid through the heat exchanger. The exchanger will then heat up the water.
These pumps are mainly used in extremely cold regions that are prone to freezing conditions.
So which is the best type of solar water heater?
Flat plate collector (FPC) are known to be more durable than the evacuated tube collector (ETC) whose tube is made of glass material.
In terms of the cost, ETC solar heater is cheaper than the flat plate collector systems. They are also more suitable for cold regions or during days when there is limited exposure to sunlight.
Flat plate collectors are also more suitable for the usage of hard water or water that has high chlorine content.
