Now most of the experienced solar collector factory gain their own keymark certificates, so why not considering such certified collectors first Solar Systems Brisbane. Collectors with keymark or withtout keymark certificate are absolutely different in quality. If there is a collector without such certificate, you even can not know how much energy they can offer every year.
Ask the suppliers to offer the keymark certificate first, or you can download from the Keymark offical website:
Read keymark certificate carefully, you will gain what you want.
1. Compare solar collectors with same size
For example of our JMC-5818-30 evaucated tube solar collector, it equiped with 30pcs 58 x 1800mm evacuated tubes. 58 x 1800mm evacuated tubes are very common from China. So you can compare it with other solar collectors from China, also with 30pcs 58 x 1800mm evacuated tubes, for example of XXX-30.
From the second page of our JMC series keymark certificate, you will see, in the condition of Power output per collector unit G=1000 W/?, Tm- Ta=0K, JMC-5818-30 can get 2180W, but another collector XXX-30 only can get 1940W (for example). That mean with the same size, JMC-5818-30 efficiency is 12.37% higher than XXX-30. If the price of JMC-5818-30 is US$ 399, while XXX-30 is only US$ 359, 10% lower than JMC-5818-30, but JMC-5818-30 still is a better choice considering the effieciency. And JMC-5818-30 can save more space, not only for container transportation, but also on your roof area, that all about money, not to mention your finally installation cost and maintenance cost. So choose a higher efficiency solar collector is always better than choose a cheaper solar collector.
2. Compare solar collectors with different size
You always will meet such problem, solar collectors from different suppliers with different size, especially that collectors from different countries.
For example, you have US$ 1200 budget for your solar heating solution. If you choose JMC-5818-30, then you will get 3pcs; If you choose another solar collectors, also you can buy 3pcs. Now please check the solar collector output, in the condition of Power output per collector unit G=1000 W/?, Tm- Ta=0K, 3pcs JMC-5818-30 can get 6540W (2180W x 3). But another collector only can get 6000W. Obviously, which is your better choice.
3. Compare the warranty
If comparing the two way above, two collectors are more or less, now warranty is very important.
JMC collectors offer 10years warranty, but most of the other collectors only offer 5-7years warranty, 40% more longer warranty means 40% more cost for factory, but save 40% money for users.