Choosing to install a solar water heater is a great idea because they can save you significant money each month on your water heating costs. However, it isn't as easy as buying a solar panel and attaching it to your roof. There are many different types of solar water heating systems available, and these are three decisions you must make when choosing your solar water heating system.
Active Heating Systems or Passive Heating System
One of the decisions you must make when choosing a solar water heater is whether you want an active or passive heating system. An active heating system mechanically forces the water around the water heating unit with the use of various controls. This makes the system extremely efficient, but because of this higher efficiency rate, an active system is more expensive than a passive heating system.
A passive heating system isn't as efficient as an active system. This is because it doesn't rely on mechanics to move the water around. Instead, with a passive system, the water tank is stored higher than the collector. As a result, when the water is heated in the collector, it naturally rises to the water tank to be used. Cold water in the water tank also naturally sinks down to the batch collector to be reheated.
Direct Circulation or Indirect Circulation
If you choose an active heating system, you have an additional decision to make: direct circulation or indirect circulation. Direct circulation is simple. Pure water is held within the collectors and heated by the sun. This water is then sent to the storage tank and directly used by you and your family.
Indirect circulation uses a non-freezing liquid instead of water. It travels from the collector to a storage tank, but instead of being used directly, the heat from the non-freezing liquid is transferred to natural water via a heat exchanger. Indirect circulation systems are best for colder climates because, as the name suggests, the non-freezing liquid can't freeze. However, indirect circulation systems can't be used with passive heating systems or with some collectors.
Flat-Plate Collectors, Batch Collectors or Evacuated-Tube Collectors
Last, you must decide which type of collector you want: flat-plate, batch or evacuated-tube. Flat-plate collectors are easy to spot. They are the traditional flat glass solar panels you see on roofs. They are filled with tubes that hold the water or non-freezing liquid. Each collector can hold about 40 gallons of water. They work with active, passive, direct and indirect systems.
Batch collectors are large dark tanks or tubes that sit inside an insulated box. The water inside the batch collector can remain there until it's needed, and the water can get very hot. Therefore, this system requires a tempering valve, which adds cold water to prevent burns. Batch collectors don't work with indirect circulation or passive heating systems.
Finally, evacuated-tube collectors consist of a series of water or liquid-filled tubes. Surrounding the tubs is another glass tube, which is designed to trap heat. Evacuated-tube collectors are the most efficient and, therefore, the most expensive collector, but they are great for colder climates because they can even work in overcast conditions. They are perfect for active, passive, direct and indirect systems.
If you live in a colder climate, your options are more limited because you need indirect circulation. However, regardless of where you live, there are several options available for your solar water heater. To get started, contact a solar water heater contractor today. Discuss your options, get a quote and find out how much solar energy could save you each month on your water heating needs, or pop over here for more information.