Compared with electric water heaters and gas water heaters, solar water heaters have many advantages:
1, solar energy inexhaustible, inexhaustible. As long as there is sunlight, solar water heaters can be light and heat conversion, can run all year round;
2, green. Solar energy as a clean renewable energy, no environmental pollution, no security risks;
3, long service life, the main components of the service life of up to 15 years or more;
4, with other energy supporting the use, can achieve all-weather operation;
5, significant economic benefits. An investment and long-term benefit is the salient features of solar water heaters. The recovery period of the solar water heater is related to the price of the conventional energy compared with that. Under normal circumstances, the investment can be recovered in one to four years.
However, there are hundreds of brands on the market today, solar water heaters, dazzling, good or bad can not distinguish, consumers have no choice. In order to allow consumers to pick to the excellent quality, good after-sales service of solar water heaters, China Solar Energy Association and the State Administration of Quality Supervision, the relevant experts recommend that consumers follow the following steps:
Step 1: Determine the amount of water used
First of all, should clear the number of permanent residents, per capita use of hot water, and then calculate the total amount of hot water a day, and then according to the total amount of hot water and 1m2 solar collectors produce hot water capacity F (75-90kg / day · m2), design Solar collector area S (m2) and insulation tank capacity V (m3). According to our many years of experience, the user per capita with 55 ° C of hot water can refer to the following parameters:
1. home users: shower spray water 80-100kg / person days, or each configured 1m2 solar collector area;
2. Factory staff, school shower Sprinkler water: 40-60kg / person days;
3. Hotel shower spray water: 80-120kg / person days;
4. Bath bath water: 300-500kg / person days.
(Kg) / F (kg) / m2, you can get the solar collector area S (m2), according to per square meter of solar collectors with 0.1m3 Of the insulation tank capacity ratio, can be calculated insulation tank capacity: V = S (m2) * 0.1m3 / m2.
The cost of solar water heaters and solar collectors and the size of the insulation tank is directly related to the relationship between the long-term relationship, from the user's long-term, comprehensive interests point of view, the appropriate choice of a larger solar collector area, Because the first time to invest a little more hot water on the solar water, after 15 years to save more operating costs.
The second step: select the solar collectors and other accessories
After the size of the solar water heater is determined, the type of solar collectors should be selected. At present, the types of solar collectors used in the domestic market are: flat type, vacuum tube type, heat pipe type, U type tube type four, four types have their own advantages and disadvantages, no one is perfect, occupies an absolute advantage of. The type of solar collector selected by the user should be selected according to the climatic characteristics of the installation location and the required hot water temperature.
For the Guangdong, Fujian, Hainan, Guangxi, Yunnan and other winter non-icing of the southern region of the user, select the flat-panel solar collectors is very appropriate, because there is no need to consider the problem of winter frost, and flat solar collector The shortcomings of the device is not frozen, so the use of the South, the shortcomings will not be shown, and the advantages of flat type is very prominent: high thermal efficiency, metal tube plate structure, maintenance-free, 15 years of life, cost-effective. Yangtze River, the Yellow River basin area users, because the winter will be frozen, and the winter temperature is higher than -20 ℃, so the choice of vacuum tube solar collectors is more appropriate, both can be frozen, cost-effective than heat pipe, U- But the main drawback of vacuum tube is: not pressure, easy to scale, easy to burst.
In the three northeastern provinces, Inner Mongolia, Xinjiang, Tibet, users must use heat pipe solar collectors, because the heat pipe anti--40 ℃ low temperature, flat, vacuum tubes are unable to resist such a low temperature, but the heat pipe cost is high, and thermal efficiency lowest.
For industrial use of hot water, the best choice for flat solar collectors. Industrial hot water consumption, the need for a large area of ​​solar collectors, requiring the collector is not easy to damage, easy maintenance, pressure, flat collector in this area has significant advantages. Vacuum tubes, heat pipes, U-tube collectors can not be used for large projects, for example, vacuum tube collectors have an average annual damage rate of 8 ‰, and a tube rupture will lead to the entire system paralyzed.
In summary, different types of solar collectors are not absolutely good and bad points, it is important to use the climate characteristics and uses of the region to choose the optimal cost-effective type, do not be misleading by some manufacturers, money.
Solar hot water system will also use the water pipes, insulation tanks, control systems and other accessories, accessories, the performance also directly affects the superiority of the entire system. You can choose copper, stainless steel tube and PPR pipe and do not choose galvanized pipe as a water pipe, which, PPR tube cost-effective; do not choose to use insulation cotton to heat the tank, because the insulation cotton will absorb water; And do not use polystyrene to heat; control system is best to use imported brands.
Step 3: Evaluate the design
Evaluation of solar water heater system design, should focus on the evaluation of the following five points, you can basically reflect the merits of the design program:
1. Is the design of hot water enough? Collector area, water tank capacity is large enough?
2. Is the auxiliary heater power enough? In principle, in the rainy days start electric auxiliary heating should be 3-5 hours to fully meet the water requirements, start the heat pump auxiliary heating should be 8-16 hours to fully meet the water requirements;
3. If the user's water consumption, water time changes, the system can also meet the user's requirements? (Because in actual use, the user's water consumption, water time is often changed);
4. Does the system achieve maximum use of solar energy and minimize the consumption of conventional energy in a variety of weather conditions, where water usage varies, that is, whether to maximize energy savings?
5. Is the price ratio highest?
If the comparison through the various programs found that the answer to the above questions are certain, it is a very good design, or as long as there is a question of the answer is no, the design is not perfect, or even not Pass, the purchaser as long as their own ingenuity, knowledge, control the above five aspects of evaluation, you can make their own ideas.
Step 4: Choose the brand
In the choice of the brand to take a small take big. Brand, is the manufacturer of a consumer credit guarantee, the big brand means more, more reliable protection. Some small and medium enterprises are holding a fishing left the mentality, product quality, after-sales service are difficult to guarantee. Solar water heater after-sales service is very important, because the solar water heater is durable consumer goods, and usually installed on the roof, once a failure, the user is difficult to solve their own, so after-sales service must be protected.
In general, there is no brand of agents or small shops only short-term service capacity, it is difficult to have long-term service capabilities, because their own existence is short-term nature; with self-brand awareness of the company or its branches after- Have long-term protection.
Really good brand rarely need after-sales service, the door after-sales service costs are lower, manufacturers are more confident to set a free warranty period longer, 1 year, 2 years, from this point of view, To a certain extent, can also speculate the merits of the product.
Another important criterion for evaluating the brand is the length of the company's history, the best choice for the history of more than 8 years of business, history means that the company's development and stability, strong viability, strength, leading technology, product quality, after-sales service is guaranteed The According to statistics, the newly established company in the 2 years the possibility of closure of 80%, therefore, the establishment of a shorter time just started the business, products and services are less mature, its own viability without time, is likely to 2 to 3 years of market competition disappeared.
Based on the above four steps, you can choose the most suitable solar water heater products and services