Common Types of Solar Water Heater Heat Exchangers
Solar water systems use different types of heat exchangers so that a transfer of solar energy to solar collectors is achieved and an air or liquid are used in order to heat water or space. A heat exchanger can be created out of bronze, steel, copper, stainless steel, cast iron or aluminum. In most situations copper is used because it has the property of being a very good thermal conductor while also providing high resistance to corrosion. Let us now think about common types of heat exchangers that you can see.
Basically we have 2 heat exchanger types: air to liquid and liquid to liquid. Heat transfer fluid is used by all heat exchangers designed for liquid to liquid solar systems. It basically circulates through solar collectors, absorbs heat and goes through heat exchangers so that heat is transferred towards the water in the storage tank. Different heat transfer fluids can protect collectors from freezing during winter. Such a liquid to liquid heat exchanger system will use 1 or 2 barriers in order to be properly effective. One heat exchanger built with a one wall system usually has a pipe or tube surrounded by fluid. Double wall exchangers are using 2 fluids and show two walls between them. In most cases a double wall solar water system will be required as the safety provided is higher. Unfortunately we can not find a lot of efficiency in them if there is a comparison to single systems. Air to liquid systems include air heater collectors. They do not usually need the use of a heat exchanger to be used between air distribution systems and solar collectors. Besides the use of air instead of liquid the two solar water heater heat exchanger systems are similar.
Sizing is always important whenever you are building solar water heat exchanging systems. If you want everything to be effective size is really important. Whenever thinking about this topic you need to consider the heat exchanger types, the heat transfer fluid characteristics, flow rates and temperatures for inlet and outlet for the fluids used. In most cases manufacturers are to give ratings for heat exchangers supplied. For you to make really good decisions you should read specifications.