How Solar Water Heating Works
1. Energy Collection: UV rays are collected and converted into heat
The solar collector which is mounted on a roof or on the ground with an angled bracket is responsible for collector UV rays and converting them into heat in a few minutes. As the sunlight passes through each evacuated tube, which is lined with a UV absorbing film, it is converted into heat and conducted into a heat pipe which sends it into a copper manifold.
Each evacuated tube is operating under vacuum which prevents any heat from escaping once it is absorbed. This guarantees a high heat transfer rate. This is almost like parking a car in the sun and having all the windows rolled up, but much hotter.
2. Energy Transfer: Circulating fluids like water or propylene glycol transfer the heat from the manifold into a heat exchanger tank where water is heated.
In the heat exchanger tank the circulating (or thermal) fluid is circulated through a copper heat exchanger where its heat is given off to the water inside the tank. The fluid then continues to circulate back up to the manifold where it is heated again. In the case of pool heating the pool water itself is pumped into the manifold where it is heated and sent back to the pool.
3. Energy Storage: The heated water is stored
The heated water in the heat exchanger tank is heated and stored. When there is a demand for hot water the heated water flows into the current heating tank where it requires little or no additional heating. When hot water is drawn from the top of the heat exchanger tank, cold water make-up enters the bottom of the tank to be heated by solar energy.
Again, for pool heating the heated water is stored in the pool itself. Cold pool water is drawn from the pool; heated in the manifolds and returned to the pool as hot water.
Solar water heating can be used to heat water for domestic hot water heating which is used in homes, offices, restaurants, cottages, farms and commercial buildings. Learn more about solar domestic hot water.
Solar Water heating can also be used for pools, hot tubs and floor heating. Learn more about solar pool heating and solar radiant heating.