Solar Hot water
EnviroGroup and EnviroShop have been installing solar hot water systems for decades so we know what will work and what won’t. Solar systems fall into two general categories:
- Rooftop Solar Collectors
- Heat Pumps
Rooftop Solar Collectors
Rooftop solar hot water systems have either rectangular solar collectors on the roof or banks of evacuated tubes. They both work on the same principles in that the collectors on the roof take in sunlight and heat and create a greenhouse effect within the collector. Water is passed through this collector, either by gravity feed or a pump, and it heats up. It is then stored in a tank on the roof or on the ground. It’s a pretty simple process. The main problem with these systems is that the further south or north of the equator they are, the worse they perform.
These systems use either a backup electric element or a backup gas heater in the event that there is not enough solar collection to adequately heat the water, so when it is very cold or very cloudy the greenhouse effect inside the collector won’t heat the water properly and the backup, or boost, is working instead. So, in the cold Victorian winter, you find that your hot water is mostly supplied by the boost and the solar benefit is poor. This makes these types of system inefficient and poor value for money. Of course, once you go further north, their performance greatly increases and they are a useful system with long lifespans.
The second problem solar collectors have is that they take up valuable roofspace which could otherwise be used for solar photovoltaic panels to create energy for the household. This is a much better use of your real estate.
Competing with rooftop solar is the heat pump. This system is a storage tank connected to a compressor similar to an air-conditioner. In fact it is an air-conditioner but working in reverse. The heat pump takes warm air from outside and by thermal exchange puts that energy into the water, heating it up. See below for the video. There are several advantages to this system.
First, the heat pump is efficient. The best ones use only a couple of kWh to heat the water. An electric tank (basically a large kettle) can use up to 14kWh/day. Immediately, a heat pump will save energy and reduce your bill. If you have rooftop solar power, you can time your heat pump to only run through the day so your solar power runs the heat pump and now you have free hot water. You still have to pay for the water, though.
Second, heat pumps are cheaper to buy than rooftop hot water. Even the best and most expensive heat pumps are still a cheaper option than most rooftop systems and thousands cheaper than decent evacuated tube systems which may or may not perform optimally.
A common complaint with heat pumps is that they are noisy and it is true that some of the cheaper units make a racket. This is why they are cheap! Quality heat pumps like Sanden or Stiebel Eltron are almost silent.
The average home uses about a quarter of the total energy consumption to heat water. As you reduce energy use in other areas, like lighting, heating and cooling, this percentage will become bigger and more significant. Finding the most effective hot water service for your situation requires knowledge of the different types of systems and their strengths and weaknesses. Installing an efficient hot water system is one of the most effective ways in which you can save energy and reduce your carbon footprint. For quality efficient hot water systems, residents and businesses choose EnviroGroup to deliver an effective energy saving solution.
When your old hot water system fails you’ll want hot water in a hurry. We can usually provide an emergency hot water system to give you time to choose the right hot water solution for you.
- Sanden Heat Pump Hot Water Systems
- Evacuated Tube Solar Hot Water Systems
- Flat Panel Solar Water Systems
To find out all you need to know about efficient hot water in Melbourne, call us now on 03 8395 3030 or complete the enquiry form and we will contact you. Be quick to receive your efficient hot water rebate!