We recently had a well known flat plate gas boosted solar hot water system installed. We get enough hot water for the price we paid, and the booster works well - but as with all of our purchases, there have been problems.
We have our panels inclined at 30%, which is within tolerance for Melbourne, but in the installation manual, it clearly says that the collector panels must slope upwards 8mm per panel from the cold inlet to the hot outlet. This makes sense to me as hot water has to rise to the highest point to be most efficient, however out panels have clearly been installed very level. From left to right the panels have no slope. As this was done via a very large supplier, there are no doubt a very large number exactly like mine.
My first question is: exactly how much difference is this likely to make?
Secondly, there are two collectors. One is nice and black inside, but the other has a lot of reds and green tinges to it - from the date of install. After a week or so I contacted Rinnai and described the colours. They were very interested and said there had been a faulty batch. They came within a couple of days and replaced the unit - with another that has the same characteristics. Lots of red and green colours on the collector fins. I'm used to the idea that black is the best heat absorber - so I dont see how the coloured panels are a good thing.
So the next question is: how important is the colour of the collectors?
Any ideas?