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Solar water heater produces hot water using Energy from Sunlight. Hot water is used for different applications, domestic as well as industrial. By using Solar Water Heaters, we can save the electricity and in turn save a lot of money. |
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Solar Water Heater consists of mainly 2 parts. One is the collector and other is the Insulated tank. The cold water in the collector get heated up and collected in the tank by thermo siphon principle. This circulation continue till the water in the tank heated up to 60-80° centigrade. The hot water in the tank remains hot for more than 24 hours, as the tank is installed using PUF. |
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In FPC, the fins are made of copper tubes with selective Nickel Chrome plating it o which the copper tubes are ultrasonically welded. These fins are covered with toughened glass in an insulated box with Aluminium frame. The efficiency of FPC is less compared to ETC. This type of collector is not suitable for hard water and for heating drinking water. |
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Hykon is having solar water heater with ETC technology which is the most advanced and state of art technology in Solar Water heaters. The efficiency is more than that in a flat plate solar water heater. ETC solar water heaters produce hot water even in winter / rainy days. The main parts of ETC solar water heaters are a Stainless steel PUF insulated tank and Evacuated Glass tube collectors. The vacuum tubes are with different diameter and length according to applications. In pressurised systems heat pipes are used. |
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Evacuated Glass tubes used as the absorber in ETC Solar Water heaters. The ETC is having two tubes with vacuum between the tubes. The outer tube is transparent allowing light rays to pass through with minimal reflection. The inner tube is coated with a special selective coating (Al- N- Al) which features excellent solar radiation absorption and minimal reflection properties. The trapped heat inside the tube will not transferred to the outer tube because of vaccum. |
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The heat pipe used in Hykon Solar Water heaters has a boiling point of only 250 C. So when the heat pipe is heated above 250C, the liquid vapourises. The vapour rapidly rises to the top of the heat pipe transferring the heat. As the heat is lost at the condenser top, the vapour condenses to form a liquid and returns to the bottom if the heat pipe to repeat the process.
Each heat pipe is tested at 2500 C. For this reason the copper heat pipe relatively soft. Because of high temperature, the glass tube is given a three layer coating. Given the strict quality control and high copper purity, the life expectancy of the heat pipe is even longer than that of the solar tube. |
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| Comparison of Flat Plate / Evacuated Tube Collector |
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As the vacuum tube is round the Sun's rays are always striking the tubes surface at right angle and thus minimize the reflection. In case of flat plate collector the amount of solar radiation which strikes on the collector will be maximum only at the noon time. In ETC systems, due to the vacuum between the inner and outer tubes, the heat retention is comparatively more than that of FTP systems. |
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| Sl.No |
Facts |
Evacuated Tube Collector |
Flat Plate Collector |
| 1 |
Sun Tracking |
Auto sun tracking due to circular shape of the vacuum tube |
Not possible due to flat design |
| 2 |
Absorption area per day |
More |
Less |
| 3 |
Water Quality
bore well / hard water |
No scaling |
Scaling maintenance required |
| 4 |
Drinkable |
Yes |
No |
| 5 |
Hot Water |
In 2 hours |
In 3 hours |
| 6 |
Space required for 100 LPD |
Over all length 6 ft |
Length of approx 10 ft |
| 7 |
Effect of weather conditions |
Efficient in rainy & cloudy days |
Less efficient in rainy & cloudy days |
| 8 |
Installation |
Easy |
Tedious |
| 9 |
Structure |
Full Stainless Steel |
Mild steel |
| 10 |
Efficiency |
Very high |
10% less than ETC |
| 11 |
Collector |
Vacuum tube |
Copper tubes |
| 12 |
Heat loss at night |
3 to 4° C |
5 to 8 ° C |
| 13 |
Weight 100 LPD |
60 kg |
75 kg |
| 14 |
Maintenance |
Very less |
Required once in 3 years |
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| Sun Tracking in ETC and FPC |
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