Choosing the right Solar Hot Water System

Choosing the right Solar Hot Water System

If you’re an experienced builder, Architect or plumber, or if you’re just building your dream home, we are sure to have the right system for you. In Victoria, new homes must have a six star rating. This means you must have a Rainwater tank, or a Solar Hot Water system installed to acheive your efficiency rating.

Here in Victoria The Sun will heat anything from 60 to 80% of your hot water year round.  In the summer, not including rainy or very cloudy days, almost all you yoru how water will be solar heated. But in the winter with short days and not much bite in The Sun the domestic hot wate rwill need to be boosted ( from say 30 degrees on a normal winter’s day) up to 60 degrees Celcius.  You acn choose to do this by Gas, Electricity or Wood Fire (backed up by electricity).  Your choice of boosting method will be the first step in determining which system will best suit your needs.

The size of your family (or home if you want to consider re-sale) will determine the size of the system, but as a general rule with solar Big is Beautiful – the larger the volume of wtaer that is being heated by The Sun in your solar tank the more days of rain and cloud you can get through without needing to burn energy to boost.

System efficiency is another consideration when choosing your solar hot water heater:-

1.   The amount af area pointing to The Sun (i.e. facing NORTH) in your solar collector is the main determinant of efficiency,

2.  There are varying efficiencies in solar collectors. In order of efficiency : evacuated tubes, high performance (Titanium coated) flat plate collectors and normal flat plate collectors, and finally Heat Pumps (that absorb heat from the ambient air temperature).

3.  The angle of the solar collector is another factor that influences efficiency. in Victoria we are about 37 degrees South which means that The Sun’s rays hit a solar collector on the pernindicular (no reflection) when the collector is set at 37 degrees at the Equinox (March 20/21 and September 22/23).  It is possible to set up the collectors at an even steeper angle to sacrifice some Summer over efficiency and get better winter gain. There are some wind load factor considerations with flat plate collectors if mounting frames are used. Close coupled systems with heat exchangers may need small adjustments if angles greater than 28 degrees are used.

4.  Glycol systems involve a heat exchange process which means approximately 5% efficiency loss

5. If wood fire is used as a boosting method then the efficiency of the solar collector becomes far less important as the wood fire in combination with The Sun will take care of most of your winter hot water needs.
Common mistakes made when buying a system include:

  • Buying the cheapest system could mean that the buyers of the home constantly run out of hot water.
  • If the booster is not be powerful enough, and two people have a shower at the same time, they could both be fighting over hot water.
  • If the solar hot water collector’s angle is too low, it could mean that the booster will be running more often, using more gas/electricity and a larger than average gas bill.

Where do we go from here?

Once we know which system suits your buildings needs and quote any additional components that may be needed to work effectively in Victoria, we can start to assess installation requirements.

Generally on a new home you would already have your own contracted plumber who will be completing your taps, vanities, laundry i.e. your homes reticulation. In order to have our plumber install the solar hot water system, we must ask; Has the other plumber run gas to the site? Are the hot & cold lines already installed? Such questions can make the installation price vary greatly. It will obvioulsy cost you more to have a separate plumber install the system because of the second callout fee.

Because of our years of experience and expertise in the industry, we find that the best way to approach new builds is to have your plumber call us and we can offer them training on Solar hot Water installation free of charge. This means that your plumber can be trained on installing the system, can quote you confidently on the install, and they will have the knowledge and training to complete installations in the future. That’s right, we give free plumber solar training to all our builder customers, this saves you time and money!

We are also happy to assess plans that you may have for a future new build, give a recommendation for a system, give our opinion on where tanks/panels/boosters should be installed, and liaise with your architects and plumbers to give you the best solution possible. We always strive to have each and every one of our systems installed to the highest level of effectiveness here in Victoria. If you require some help in choosing a system, have a look at our New Homes Recommendations.

So If you’re looking at a large project with acres of new homes, or if you’re building your dream home yourself and need advice on energy efficiency, request a quote or phone us on 03 9328 4884.