Although solar water heaters, energy saving, but the uneven quality of products on the market, consumers should pay attention to when choosing to shop around, so as not to step into a trap of unscrupulous businessmen. Specifically, pay attention to the following eight points:
A look at the thermal performance. The average daily efficiency as high as possible, the average heat loss coefficient as low as possible.
Second, to see the vacuum quality. The key components of domestic solar water heater vacuum tube, vacuum quality directly affects the performance of the product. Purchase should carefully observe the coating on the glass vacuum tube, the coating layer is called the solar selective absorbing coating, the coating color will be different due to different production process of the manufacturers, but are generally black, dark blue or dark gray. Good quality coating color uniformity, film no scratches, no peeling or shedding phenomenon, no stones or nodules on the phenomenon of glass, the glass support within the support placed upright, not loose.
Third, look at the tube spacing between the vacuum tube. General two center distance of about 70 mm is appropriate.
Four to see the water heater. Popular on the market of solar water heater water tank divided into a stainless steel liner and the enamel interior, two. Stainless steel liner technology sub-seams and welded liner. Material thickness thin and thick stainless steel. Grades of stainless steel is divided sas304, sas403, and so on. Seams, process quality is not guaranteed. Welding of thick stainless steel (70.5 mm) welded joint after welding process has occurred changes in the internal structure of the corrosion, easily, life is not guaranteed, the general life of five years or so. Welding of thin stainless steel life is shorter, and easily deflated. Enamel interior is divided into ordinary enamel, enamel, titanium sapphire enamel interior enamel interior is ordinary enamel, the enamel of the daily enamelware, life in about two years. Senior enamel interior chemical enamel evolved, much better than ordinary enamel, the general life of five years or so. Titanium Sapphire enamel liner imports enamel, acid reached the AAA level, dense with degree more than the Class I, more than European standards, life expectancy of more than 15 years.
Five to see the water heater structure. The solar air conditioning system structure refers to the connection between the tube and the water tank. There are two currently on the market rely on silicone ring seal, the other sets of copper metal seal structure. Silicone ring seal of the solar water heater maintenance is not convenient, easy to leakage, once the leakage, the entire solar water heater will be paralysis can not be used. Copper sets of sealing a solar water heater because the use of double wall heat pipe vacuum tube, the machine can withstand pressure, high temperature, copper sets is not easy to aging, and maintenance easy.
Six to see the reliability of the auxiliary heating, including life and safety of two aspects. Electric auxiliary heating is indeed a convenience to consumers, you can enjoy every day bath, but the choice is not good, and life safety to the user at risk. Security depends on the quality of the electrical heating element and whether the guarantee does not dry on two factors. Previous factors require manufacturers to guard the checkpoint quality, a factor related to the structure, not dry must ensure that the electrical heating element is immersed in water for a long time. This requires that the structure of the water heater structure, sets of copper tube heat pipe vacuum tube, use top water type.
Seven to see water heaters inconvenient. Inconvenient, that is not automatic water currently on the market to play a lot of automatic tube solar water heater meter "computer controller" automatic water reserve tank "of the concept of automatic water, these products all glass vacuum tube water heater, water tank using a thin stainless steel liner, because the machine can not be under pressure to rely on a secondary instrument. Automatic Sheung Shui, pressure top water type water heaters do not have the instrument to implement this feature.