Which solar hot water system is right for me?
The right choice of a solar hot water system largely depends on the climate in your area.
A Solar Hot Water System is a great way to get hot water without paying too much for it. When you use a lot of domestic hot water, then you never have to worry about your energy bill or running out of hot water again.
Are you looking for a DIY Solar Hot Water System? Check our review on DIY guides here!
Warm or cool climate?
The most important factor that determines the choice of your Solar Hot Water System is the solar radiation but especially the temperatures in the region that you live in.
When you live in the southern states where temperatures hardly drop below freezing point, the most efficient and economical choice are passive Solar Hot Water System or active open-loop Solar Hot Water System. If your region is prone to freezing, active closed-loop systems are the best choice. If you have no idea what I´m talking about…keep reading, I´ll try to explain.
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An active or passive Solar Hot Water System
- In an active Solar Hot Water System you are using pumps and controls to manage water temperature. Active solar water heater systems normally have a drawback: They are more costly and the system needs electricity the pump the water around, though this active-system is required in colder regions. Obviously, DIY systems you can keep costs low.
- A passive Solar Hot Water System relies on natural sources. Through gravity and convection the water will circulate, and warm up. This system is cheaper and more durable than the active system, but is also less efficient.
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This is how an active Solar Hot Water System works
When solar fluid in the collector (1) is heated by the sun, it is pumped through the heat exchanger (2), which then heats the water in your storage tank (3). The solar fluid then circulates back up to the collector, where it gets reheated by the sun. The whole process automatically continues as long as the sun heats the collector. When there is little or no sun, a backup heating element self-activates to provide ample hot water for your home.
You want to go for an Active Solar Hot Water System?
When you are choosing an active system you will have to decide or you will use a direct or indirect solar water heating system.
- In a direct Solar Hot Water System (open loop system) the water is heated directly inside the pipes or plates. The water is flowing through the pipes and when the sun is shining the water will be heated. An open loop system is the ideal Solar Hot Water System when you are living in a warm region and it is the least expensive of the two systems.
- An indirect Solar Hot Water System (closed loop system) is often used in colder climates. The pump circulates a non freezing heath- transfer fluid through the collectors and pipes. This fluid usually is a glycol water anti freeze liquid. The water is stored in water tanks. Heath exchangers will transfer the heath from the fluid to the water.
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Is the passive Solar Hot Water System more for you?
The passive Solar Hot Water System technology is widely used in the warmer areas. It´s a relatively cheap and durable technology. It requires only few parts and no electrical pump as the water flows through the system based on the great principle of fysics that heated water rises as cooler water sinks. This makes it also a great DIY project. If you consider this system though, be sure that you don´t have too cold nights as the pipes could freeze.
Conclusion:
When you live in an area where temperatures hardly drop below freezing point, then your best bet is a passive hot water systems (no freezing temperatures) or active open-loop systems (few days of modest freezing temperatures). If your region is prone to freezing, active closed loop systems are the best choice. .
The installation costs of a solar hot water system by professional solar hot water contractors can be considerable. An active Indirect Solar Hot Water System is the most efficient but also most expensive and run around a whopping $15,000!. A cheaper alternative are the Pre-build Solar Hot Water System kits that run between $2,000 – $8,000 (check our financial analysis). Or consider doing it yourself. There are some great manuals in the market that guide you through this process (you don´t have to be a DIY black-belt!!!) with great explanations and video images.
