Iran lies between 1 to 2 degrees north latitude and is located in a region that is among the highest in the world in terms of solar energy. The amount of solar radiation in Iran is estimated at between 2 and 4 kWh per year, which is above the global average. In Iran, on average, there are more than 5 sunny days per year, which is very significant.
Solar water heaters, as their name implies, act by absorbing solar radiation energy from the collector plates, and their heating efficiency varies depending on geographic location. The spa reservoir is designed to provide the spa with storage overnight and its thermal losses are low until the next morning and rise again.
This system can significantly reduce the cost of gas-oil and electricity consumption, which will be more tangible in large-scale projects, which can save about 2 to 4 years on fuel consumption. Fossil depreciated the initial investment. Maintenance costs for these systems are very low. The service life of the systems reaches the standard and high technical quality up to 5 years.