As a consumer you will potentially be overwhelmed by the range of solar water heaters available on the market. After extensive product research and R&D under NZ climatic conditions we determined that the Solar Fin Vacuum tubes provided:
Highest consistent energy output and fastest response rate to fluctuations in solar radiation
No vacuum failures
Solar Fin Vacuum tubes - Ultimate in performance and minimum 20 year service life
HP70 - 70mm x 1,900mm Solar Fin Vacuum Tube with Heat Pipe
HP100 - 100mm x 2,200mm Solar Fin Vacuum Tube with Heat Pipe
DF100 - 100mm x 2,200mm Solar Fin Vacuum Tube
There is a common misconception that solar water heaters require direct sunlight, and hence you need to live in the place with the most sunshine hours - ie Nelson, in order to benefit.
Advances in solar collector coating technology means that a much broader light spectrum can be harnessed and converted into heat energy. The patented selective coating on our solar fin converts not only visible light, but also UV-A, UV-B and IR radiation into usable heat energy.
The graph below demonstrates the relationship between sunshine hours and solar radiation levels in the main centres of the North Island, with Nelson included as a comparison. You will note that the solar radiation is considerably higher and more consistent throughout New Zealand. Source: NIWA.
Even the average monthly radiation levels are fairly consistent down the length of the North Island. Source: NIWA
From the previous graph you will note that the average solar radiation levels reduce during winter time. From day to day there will be radiation extremes. During summer the radiation levels can also be extremely low due to overcast weather or periods of rain. During clear frosty days mid winter, the solar radiation levels can reach those of the summer time.
if you are seeking optimum all year performance and maximum water heating efficiency you need a solar collector that will generate heat energy under the most extreme conditions.
The graph below demonstrates the difference in energy output between our three Solar Fin Vacuum Tube and three of the industry leading Flat Panel Solar Thermal Collectors.
The above graph compares the collector performance efficiency when the collector water temperature vs air temperature differential is at 50°C at different levels of radiation.
For example, the collector must try to heat water to 60°C but the air temperature is only 10°C. If the Solar Thermal Collector energy output (MJ/d) is low, this indicates that the collector can not efficiently convert solar radiation into heat energy to heat water at that particular level of solar radiation. This may be due to the selective coating or poor thermal insulation resulting in a loss of heat energy to the atmosphere.
The graph below compares the difference in water heating performance between our HP100 Solar Thermal Collector and a top of the range Titanium Oxide Flat Panel Collector, across a whole range of temperature differentials and different levels of solar radiation. Our vacuum tube collectors are strides ahead.
HP100 Solar Fin Vacuum Tube Tinox Flat Panel Solar Collector
In our opinion a solar thermal collector in New Zealand is of little use unless it will respond rapidly to the four seaons in one day scenario and can perform efficiently in our temperature extremes.
Unlike flat panel collectors, which suffer from a considerable loss in heating efficiency when the outside air temperature drops, our solar fin vacuum tube solar thermal collectors will continue to perform throughout the year, irrespective of the air temperature or bone chilling winds.
This is due to the unique vacuum that surrounds the 'Solar Fin'. A vacuum is an effective form of thermal insulation and reduces heat loss to the bare minimum. Much like how a high quality thermos flask keeps its contents hot for days, we ensure no heat is lost from the 'Solar Fin'.
This thermal image was taken during the winter. The bright coloured areas indicate heat loss by radiation to the atmosphere. A lot of heat is last from the hot water passing through the Flat Panel Collector. The thermal insulating properties of the vacuum surrounding the 'Solar Fin' of the HP100 tubes are clearly evident in this image. When combined with the superior heat output under low solar radiation conditions, this makes the Solar Fin vacuum tube the clear choice for year round home and water heating applications.
The thermal insulation of our vacuum tubes is so efficient that our HP70, HP100 and DF100 vacuum tubes will continue to heat water even when the outside temperatures drops to -35 °C.