There are too many brands now, many of which you've never heard of before. You'd better check for yourself and give you some suggestions.
Here are some tips for choosing the right solar energy. I don't think professionals use it as a reference.
1. Look at the appearance (fine manufacturing) 2. Look at the backing (strong and corrosion resistant) 3. The thickness of the water tank coating. (weigh the weight) 4. The color of the vacuum tube (single, all) Whether there is no color difference, it is consistent. If any of them don't work, I suggest you don't buy it. I'm talking about the key elements. The capacity is 30 to 40 liters for each person. Measure the volume of the water tank, subtract 5 centimeters. insulating material, and calculate the covering of the water tank. Do not listen to the volume indicated by the trader. What they quote usually includes the volumee of the vacuum tube. You won't be able to use the water there. few additional functions possible (increased installation and maintenance costs). It is best to ask the trader to install a return pipe to ensure that if you install the microcomputer and do not use it for a few years, the solar energy can be used normally. Installation materials and after-sales service can only be evaluated. after installation. I hope this can be useful to you