Solar hot water systems can often feel like a complicated option but they shouldn’t have to be. And there are some distinct differences between flat panel collectors when compared to evacuated tube collectors.
So just what are evacuated tubes?
Evacuated tubes passively track the sun throughout the day giving the highest possible performance from early morning through to late afternoon. Their round tube design means that they’re able to capture more surface area sunlight than a standard flat panel collector. And they don't hold large volumes of water, which makes them lighter to install on the roof than some other alternative options.
Step 1 – sunlight strikes the dark absorber coating inside the tube
Step 2 – the heat pipe transfers the heat up to the copper header pipe inside the insulated manifold box
Step 3 – a circulator moves water from the storage tank to the copper pipe, warming the water. The solar heated water is then pushed down into the storage tank for you to use.
The great news about evacuated tube is that not only is it much easier for your plumber to install, you won't be out of hot water in the very unlikely event that one of the tubes gets damaged. The unit will still continue to operate, and all it takes it a quick visit by your plumber and a simple replacement of the damaged tube. However they have been tested to withstand a 30mm steel ball, so we don't anticipate you'll need to be replacing too many tubes anytime soon!
What happens during winter?
Even with a limited amount of the sun shining, you'll still be able to get some solar impact from your evacuated tubes. The evacuated tubes are efficiently designed to harness as much UV light as possible to help generate hot water. And if the weather is particularly unkind, that's why there's the backup booster with both the electric and gas solar options. The backup booster serves a couple of purposes – it ensures you have hot water where the solar gain is too low, and also to protect against legionella bacteria. So for these two reasons, it's important you keep your booster switched on.
Have a chat to your plumber when it comes time to get a new hot water unit, or when you're replacing your existing one. Solar might just be a good choice for you.