Frequently Asked Questions

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Somebody told me that the flat panel collector absorption is 88%, which is only about 5% lower than your collector's. How can GreenLand Systems claim their collector efficiency to be over twice as high as that of many flat panel collectors?
When we talk about efficiency, we must also mention the ambient and other factors. Sales representatives normally tell you only the good news about efficiency, but can forget to tell you that the peak efficiency of their collector only occurs on hot summer days, and not during the rest of the year. GreenLand Systems solar collectors can perform very efficiently the whole year round, even in winter, or on a cloudy day, when most other collectors cannot collect any heat at all. Please refer to our specifications page for year-round performance comparisons.
What is a typical power usage of the water circulating pump in a split-type solar heating system?
Typically the ratio between the pump power consumption and the solar energy that you collect free is about 1:200 in domestic solar water heating systems. This means that the circulating pump uses about 0.5% as much energy as provided free by the solar collector. In large commercial/industrial solar heating systems this fraction is even much smaller. It can be as low as 0.1% or less.
How heavy is GreenLand solar collector?  Do we need any roof strengthening before installing GreenLand solar collectors?
Usually you do not need any roof strengthening, because GreenLand solar collector are very light. Each GreenLand collector weighs less than 100kg.
What guarantee does Greenland systems offer?
GreenLand solar vacuum tubes are guaranteed for fifteen years. The collector remains operational (without any fluid leakage) in the event of a vacuum tube failure.
What is the glass tube made of?
The glass tube is made of high-impact, 2.5 mm thick, borosilicate glass with a high IR light transmittance rate of over 94%. In order to reduce convection heat losses, the glass tube is evacuated to an absolute pressure of <0.001 Pa. This is one hundred million times less than standard atmospheric pressure. Long term stability of the vacuum is ensured by carefully designed getters. Sealing between the glass tube and metal end-plate is achieved by employing new and unique technology.
Will the glass tube withstand hailstorms, and what about replacements?
The high strength glass protects the tube’s internals from harmful environmental factors ensuring a long service life of the tube. The glass tube can withstand hail of up to 3.5 cm in diameter (about the size of a golf ball) without damage. In the unlikely event of a breakage, the GreenLand vacuum tube can be replaced, while the entire heating system remains in full operation. Changing a GreenLand solar vacuum tube is about as easy as changing a light globe.

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