How to Design a Solar Heating System Effectively

Key points and precautions for the design of solar heating systems

Solar heating and solar hot water projects are different. The key difference lies in that the hot water project focuses on the annual average energy efficiency, while the heating project is only used during winter and the heating period, and the system needs to obtain the most heat at the coldest time. 

When designing solar heating systems, it is necessary to take into account the characteristics of sunlight in winter and ensure that the collector receives the maximum amount of heat on the winter solstice. 

In winter, the intensity of solar radiation is low, and the angle of incidence of the sun is small. Especially in regions with higher latitudes, the angle of the sun in winter is even lower. To increase the heat absorption of the vacuum tube solar collector, it is necessary to ensure that on the winter solstice, the sunlight forms a 90-degree angle with the vacuum tube, and the spherical surface of the vacuum tube is perpendicular to the direct sunlight. Only in this way can the maximum amount of sunlight heat be absorbed. Another advantage of this is that it can minimize the amount of sunlight radiation received by the collector in summer, and can reduce the degree of high temperature overheating of the heat collection system in summer. 

In addition to meeting the above basic conditions, BTESolar, based on years of engineering practice, has summarized five aspects of design experience: 

First, ensure efficient heat collection by the system

Firstly, the quality of the vacuum tubes must be strictly controlled. Select heat-absorbing elements with high light-to-heat conversion efficiency. Secondly, ensure that there is no obstruction in front of the collector and receive as much sunlight as possible. During the system design process, pay attention to the angle of the collector, the local latitude, the solar angle, the spacing between the front and rear rows of collectors, and other comprehensive conditions. The icing on the vacuum tubes has a significant impact on the heat collection effect, and this point is often overlooked. In winter, the duration of sunlight is short. If the defrosting time of the collector is too long, it will not receive sufficient sunlight. Staray Sunlight's approach is to achieve rapid defrosting of the collector by strengthening the structural design of the product itself and appropriately adjusting the hole spacing between the heat collection tubes. After practical testing, the effect is very good. 

Second, achieve efficient heat retention

The concept of heat retention means minimizing the loss of system heat for non-heating purposes. This requires a reasonable product design. Staray Sunshine has very strict requirements for the thickness of the insulation layer and the density of the foam in the bucket box. Specific numerical indicators are clearly stipulated in the "Distributed Solar Heating Installation Specifications" compiled by Staray Sunshine. Those interested can refer to and search for them. In addition, the design of the breathing system needs to be strengthened. The specific solutions are detailed in the "Specifications". In summary, every effort should be made to eliminate the chimney effect in the exhaust system and retain high-quality heat. 

Third, ensure proper heating

This refers to the methods and approaches for using heat. During the heating process, it is necessary to distribute the heat reasonably, maintain a balance between storage and supply, and achieve proper temperature control and scientific heating usage. For example, in places where heat is only used during the day, waste of heat energy can be avoided through time-based control. For rooms that are not occupied or used by people, by using room-by-room control, the heating pipes can be prevented from freezing and cracking without wasting heat energy. Through the above control methods, energy utilization becomes more precise, which is what is called "reasonable" heating. Reasonable heating is to save energy for users and create economic value. 

Fourth, it is important to pay attention to the design of the system's lifespan indicators

During the design process, high-quality configurations should be made based on the set usage period and the effective lifespan of key components, aiming to achieve the goal of all components having the same lifespan and reducing maintenance costs. While ensuring effective heat collection, the lifespan of the system should be extended as much as possible. The longer the system's lifespan, the more beneficial it is to users and the greater the contribution to clean energy. One cannot cut corners for short-term benefits and abandon the system after only a few years. 

Fifth, ensure the system operates stably in winter

Users cannot tolerate the inconvenience caused by power cuts during winter. Therefore, when designing, stability should be given top priority. This is the core of system design and requires rigorous calculations. Design cannot be based on intuition. In cases where solar energy is limited, local conditions should be considered and the utilization of supplementary energy should be reasonably planned to ensure stable power supply. In addition, the quality management of system components should be strengthened to minimize system failures and reduce the maintenance rate as much as possible, so as to make customers feel at ease and save money. 

From the above five aspects, it can be seen that solar heating is by no means a simple system assembly. It is a comprehensive coordination of multiple disciplines of technology, and the knowledge involved is also very extensive. For example, one needs to understand water supply and drainage design, know the physical principles such as thermal expansion and contraction, the specific gravity of hot and cold water, the pathways of heat conduction, and know the basic design requirements such as maintaining hydraulic balance and the same course of hot and cold water during system operation. In addition, it also involves the application of knowledge related to power, steel structure, and civil engineering infrastructure.