Although the energy saving solar water heaters, but the quality of the product on the market uneven, consumers should pay attention to purchase more than three, so as not to enter the trap of illegal business cloth. Specifically, pay attention to the following eight points:
A look at thermal performance indicators. The average daily efficiency of the higher the better, the average heat loss coefficient as low as possible.
Second look at the quality of vacuum tubes. Household solar water heater is a key component of the vacuum tube, vacuum tube quality directly affects the performance of the product. Purchase should be carefully observed in the vacuum tube on the glass tube coating, this layer of coating called solar selective absorption coating, due to the manufacturers of different production processes, coating color will be different, but are generally black, dark blue Or dark gray. Good quality coating uniform color, no scratches on the film, no skin or shedding phenomenon, there is no stone on the stone or nodular phenomenon, support the glass tube support pieces placed correct, not loose.
Three to see the tube between the vacuum tube spacing. Generally the center of the two tubes in about 70 mm is appropriate
Four to see the water heater liner. Currently on the market popular sun water heater tank liner sub-stainless steel liner and enamel liner two. Stainless steel liner by the process of sub-mouth and welding liner. According to the thickness of the material is thin, thick stainless steel. According to the grade of stainless steel and sas304, sas403 and so on. The quality of the mouth is not guaranteed. Welding of thick stainless steel (70.5 mm) welding by the welding process has been the internal structure of the changes, easy to corrosion, life is also difficult to guarantee, the general life of about 5 years. Welded thin stainless steel life is shorter, and easily pumping deflated. Enamel liner is divided into ordinary enamel, senior enamel, titanium sapphire enamel liner, ordinary enamel liner is used in ordinary enamel enamel enamel enamel, life in two years or so. Advanced enamel liner from the evolution of chemical enamel, much better than ordinary enamel, the general life of 5 years or so. Titanium sapphire enamel liner imported enamel, acid to AAA level, close to more than I level, more than the European standard, life expectancy in more than 15 years.
Five to see the water heater structure. Water heater structure refers to the connection between the heat pipe and the water tank. Currently there are two kinds of the market, one by silicone ring seal, the other is a copper structure of the metal seal. Silicone ring sealed solar water heater maintenance is not convenient, easy to leak, once the water leakage, the entire solar water heater will be paralyzed can not be used. Copper sleeve sealed solar water heater because the use of double-walled heat pipe vacuum tube, the machine can withstand the pressure, high temperature, metal copper sets are not easy to aging, the use of maintenance are very convenient.
Six to see the reliability of auxiliary heating, including both life and safety aspects. Electric auxiliary heating does bring convenience to consumers, can guarantee that every day to bath, but the choice is not good, but also to the user's life safety hazards. The safety depends on the quality of the electric heating element and whether it is guaranteed that the two factors are not dry. The former factor requires the manufacturer to keep the quality off, after a factor and structure closely related, do not burn must ensure that the electric heating element is immersed in water for a long time. This requires the structure of the water heater for the copper sleeve structure, collector tube for the heat pipe vacuum tube, the use of methods must be top water.
Seven to see the use of water heater is not convenient. The so-called convenience is not convenient, that is, can not automatically Sheung Shui, the current market, the concept of automatic Sheung Shui a lot, what "automatic water meter", "computer control instrument" "automatic water tank", all of these products are all Glass vacuum tube water heater, tank liner with thin stainless steel liner, because the machine can not pressure, can only rely on auxiliary instruments to achieve. The real automatic Sheung Shui, that is, under pressure top water-type water heater, no instrument can achieve this function.
Eight to see after-sales service. The best choice for well-known brand products and good after-sales service dealers, because the home solar water heater is durable consumer goods, and is usually installed on the roof, once the failure of the user is difficult to solve their own, so after-sales service must be protected.