Should first clear user Usual number of per capita amount of hot water, and then calculated the day the amount of hot water, hot water total 1m2 of solar collector hot water production capacity F (75-90kg / day / m2), design solar collector area S (m2) and holding tank capacity V (m3). According to our years of experience, the user can refer to the per capita amount of hot water 55 ° C the following parameters:
1, for home users: shower spray water 80-100kg / person / day, or per person configuration 1m2 of solar collector area;
2, factory workers, school shower spray water :40-60kg / person / day;
3, the hotel shower spray water :80-120kg / person / day;
4, soaking in the bath water :300-500kg / person / day.
Determine the day's hot water total P (kg), P (kg) ÷ F (kg) / m2, you can get the evacuated tube solar hot water collector area S (m2) per square meter of solar collector with 0.1m3 the relationship between the ratio of the holding tank capacity, we can calculate the holding tank capacity: V = S (m2) * 0.1m3/m2.
Is directly related to the cost of solar water heaters and solar collector area and the holding tank capacity, close to the proportional relationship between the users long-term, comprehensive benefits point of view, the proper selection of the larger solar collector area, user-friendliness, Because the initial investment a little more solar hot water on some of the next 15 years and more the province running costs.
Step 2: Select the solar collectors and other accessories
Solar water heater size is determined, it should be the selected type of solar collector. Domestic market with the type of solar collector: flat plate and vacuum tube type, heat pipe, U-shaped tube, four, four types of advantages and disadvantages, no one is perfect, an absolute advantage the. User to select the solar collector types should be based on the installation location of the climatic characteristics and the required hot water temperature, use to select.
Different types of solar collectors is no absolute good, the bad points, it is important to select the best type of cost based on the use of regional climate characteristics and uses, do not be misled by some manufacturers to spend more time and money.
Solar water heating systems will be used in water pipes, tank insulation, control system parts, accessories, performance is also directly affect the superiority of the entire system. Brass, stainless steel pipes and PPR pipes can choose to instead choose galvanized pipe as the water pipes, which, PPR pipe the most cost-effective; do not choose a tank, cotton insulation to insulation because the insulation will be absorbent; end of the collector plate insulation cotton instead of polystyrene insulation; control system for the best selection of imported brands.
The third step: evaluation design
Evaluation of solar street lamps system design should focus on evaluation of the following five points, you can basically reflect the pros and cons of the design:
1, the design of heating water is enough? Collector area and tank capacity is big enough?
2, the auxiliary heater power is big enough? In principle, in the rainy days to start electric auxiliary heating should be within 3-5 hours to fully meet the water requirements to start the heat pump auxiliary heat 8-16 hours to fully meet the water requirements;
3, if the user's water consumption, the water time to change, the system can meet the requirements of users? (Because in actual use, the user's water consumption, water time is often changes in the);
In a variety of weather conditions, a variety of water time, water consumption change, whether the system has reached the maximum use of solar energy, conventional energy consumption, at least that is, whether to maximize energy efficiency?
5, cost is the highest?
By comparing the various options and found the answers to these questions is yes, very good design, otherwise as long as there is a question the answer is no, the design is not perfect, or even no pass, as long as the buyers with their own wisdom, knowledge, control over the five aspects of evaluation, you can make your own decision.
The fourth step: try to choose the brand
To homes, "small" in the brand of choice to take the "big". Brand, is a faith and credit of manufacturers to consumers, big brand means more and more reliable protection. Some SMEs are holding fishing left an attitude, product quality, service is not guaranteed. Very important after-sales service of solar water heaters, solar water heaters, consumer durables, and is usually installed on the roof, once a fault, the user is difficult to solve their own, so after-sales service must be guaranteed.
In general, does not have its own brand of agents or small shops only a short-term service capacity, it is difficult to have long-term service capacity, because of the short-term nature of their existence; the Company or its affiliates after-sales service compared to self-brand awareness There are long-term protection.
Seldom need the site after-sales service really good brand, its site after-sales service expenses are relatively low, manufacturers have more confidence to set a longer warranty period for free, 1 year, 2 years, from this point of view, to some extent, can also be speculated that the pros and cons of the product.
Another important criterion for evaluation of the brand is the length of the company's history, the best choice for the enterprise of history more than eight years, a long history means that the company's development and stability, survival ability, strength, technology leadership, product quality, after-sales service guaranteed . According to statistics, the newly established companies the possibility of failure at 2 years was 80%, therefore, the establishment of the shorter business has just started, products and services is less mature, their ability to survive without the test of time, is likely to 2 to 3 years of competition in the market disappeared. Of course not to say that the new company on the point to be trusted, if they do not understand this technology, you can find related knowledgeable people to help, in some cases, a new company to be able foothold in a number of competitive, often have their own unique advanced technology!