Energy efficiency levels are divided according to energy efficiency coefficients. The energy efficiency coefficient is calculated using the heat gain and heat loss formulas. Energy efficiency coefficient ≥ 0.5 is the first level, 0.32 ≤ energy efficiency coefficient ≤ 0.5 is the second level, and energy efficiency coefficient < 0.32 is the third level. For details, please see “GB26969-2011”·
By understanding the process and content of national sampling inspections, and after summary and research, it It is recommended to follow the following steps to select a solar water heater. water heater:
One thing to look at: product quality and technical indicators
The main performance indicators of solar water heaters are thermal efficiencye average and the average heat loss coefficient of solar water heaters. These two indicators are key indices that determine the heat capture and insulation capabilities of solar water heaters. Generally speaking, the higher the average thermal efficiency, the higher the heat collection capacity of the product; and the lower the average heat loss coefficient, the stronger the heat storage and insulation capacity of the product.
Carefully observe the coating on the glass tube inside the vacuum tube. This coating is called selective solar absorption coating. A good quality coating has a uniform color and does not show scratches, peeling or peeling. or nodules on the glass, and the brackets supporting the inner glass tube are seated correctly and not coming loose.
Pay attention to the distance between the vacuum tubes. Generally, the center distance between the two tubess is approximately 70 mm.
Pay attention to whether the reflector design of the product can make full use of the heat-absorbing surface of the vacuum tube and whether the vacuum tube can receive light to the maximum extent.
Generally speaking, in winter and sunny days, it should be used with electric heater, so you should also choose products with electric safety design.
Check the thickness of the water tank insulation layer. The thickness of the flat insulation layer should be 45mm as standard and the overall polyurethane foam insulation is best. Polyurethane foam is light yellow, a bit like a sponge. The foam has relatively uniform pores and exhibits some elasticity when pressed by hand. However, if the insulating layer is too soft, it means that its density is low, which is not conducive. heat preservation.
The design of the support of domestic solar water heaters should be reasonable and should have sufficient strength and rigidity to ensure sufficient bearing capacity. This is particularly important in coastal cities.
Second consideration: brand protection and service quality
When choosing a brand, we should abandon the "small" and choose the "big". Big brands mean more and more reliable guarantees.
The after-sales service of domestic solar water heaters is very important. Since domestic solar water heaters are consumer durable goods and are usually installed on the roof of a building, once a fault occurs, it is difficult for users to resolve it themselves, the service after-sales must therefore be guaranteed. It is best to choose well-known brands and dealers with good after-sales service and check the prices.national related product quality inspection pports.
Three things to consider: the actual needs of your own family
When purchasing a solar water heater, you should also consider the number of permanent residents in the house to determine the water flow. capacity of the domestic solar water heater you purchase. Generally, the standard of 40 liters of water per person is appropriate. In addition, when purchasing, you should clearly ask the seller what its rated water capacity is. This is the total water capacity or the actually usable water capacity, and the difference between the two.
It should also be noted that a truly useful solar water heater must be able to provide consumers with enough hot water even on rainy days and other times when the intensity of the sun is very weak.
Standards for evaluating solar panels
The standard “Limiting values of effective"Energy acity and energy efficiency levels of domestic solar water heating systems" was developed by the relevant organizations in the solar energy use sector after carrying out assessments of more than 60 solar energy companies. The products are formulated after testing and research. The standard includes: Divide the energy efficiency label of home solar water heating systems into three levels, level one is the best, level two is second, and level three is qualified. Only those who meet the level three energy efficiency standard are allowed to do so. be placed on the market; The energy efficiency coefficient includes ""Heat gain" and "heat loss" are two items, which is an overall coefficient. According to the conversion, if this coefficient reaches 0.15, it belongs to the energy efficiency level 3, if it reaches 0.3, it belongs to the efficiency levelenergy efficiency 2, and if it reaches 0.5, it belongs to energy efficiency level 1.
After the implementation of energy efficiency labeling, solar water heaters have their own industry standards. When consumers purchase solar water heaters, they can know at a glance which products meet national standards and which products have high energy efficiency. Of course, consumers will choose solar water heaters with high energy efficiency, and solar water heaters without energy efficiency labels will surely be eliminated from the market. build a beautiful China.
Solar panel rating standards should be based on national testing standards. Solar panels that can meet national standards are qualified. This standard was proposed by the Materials Technical Subcommittee of the National Technical Committee for Standardization of Semiconductor Equipment and Materials(SAC/TC203/SC2). This standard is under the jurisdiction of the Materials Technical Subcommittee of the National Technical Committee for Standardization of Semiconductor Equipment and Materials (SAC/TC203/SC2). 1. Appearance requirements: The appearance of solar grade polysilicon blocks must have no visible cracks, edges, chips or gaps; 2. Performance: The performance requirements of solar-grade polysilicon blocks must comply with various testing standards; Oxidized interlayers are not permitted in solar-grade polycrystalline silicon blocks; Shadows, impurities, cracks and microcrystals should not appear in the IR test results of solar grade polycrystalline silicon blocks. There must also be a production certificate on the outer packaging. The geometric size deviation of solar grade polycrystalline silicon blocks does not exceed ±0.5mm. The breakdownsSolar are devices that absorb sunlight and convert solar radiation energy directly or indirectly into electrical energy by photoelectric effect or photochemical effect. The main material of most solar panels is "silicon", but due to its high production cost, its general use remains. has certain limits.