Heating up water is the biggest contributor to greenhouse gas emissions in the average home, accounting for for nearly a quarter of a typical Australian household’s emissions. Selecting a hot water system that is most suitable and efficient based on the size of your household, patterns of water use and climate can help you reduce greenhouse gas emissions, as well as saving you considerable money in ongoing costs.
So what type of hot water system is most suitable for me?
There are 3 types of systems, each with their own advantages.
If you’re looking at purchasing a new hot water system the first thing you need to decide is the type of system.
Electric hot water system
These are generally the cheapest systems to buy, and can be setup indoor or outdoor, allowing flexibility on where you install it. However most run on peak electricity, meaning they are the most expensive option in terms of ongoing costs. Off peak storage units (available in some areas) allows you to heat water overnight when tariffs are lower, but you would need to purchase a larger tank to ensure there is enough hot water to get you through the day.
Another option for an electric hot water system is heat pumps. These extract heat energy from the air and use it to heat water. Heat pumps use considerably less electricity than conventional systems making them very efficient. But upfront costs and ongoing maintenance can add up. The noise can also be problematic if your house is very close to your neighbours.
Gas hot water system
A gas heater is more expensive to purchase, generally around $500-1000 higher than an electric system. But ongoing costs will be lower since gas is cheaper than electricity and there are no tariffs so prices won’t fluctuate throughout the day. Another advantage of this is the units don’t need to be as large because they can operate whenever required.
Gas systems are typically for outdoor use but if they have a flue can also be setup inside. They also come with an energy efficiency rating, allowing you to see which brands and models are most efficient, allowing you to make an educated choice.
If you decide upon a gas hot water system, you also need to choose whether it will be storage or instant (continuous flow). Storage is more common, and stainless steel (while more expensive) will require less maintenance than standard steel tanks. Instant gas heats water as you need it and are generally cheaper to run because no heat gets lost. A high efficiency gas storage or instant system will serve most houses very well.
Solar hot water
In terms of upfront costs, this option is the most expensive. A solar hot water system requires both a storage tank and solar panels. But once setup, a solar hot water system has very low running costs, getting “free” energy from the sun. So over the years, the initial system is paid off (and then some) due to much lower electricity bills.
Solar hot water systems will typically also come with a gas or electric booster element to provide hot water on days of little sunshine, or when demand exceeds supply.
Graph from Sustainability Victoria
How much hot water do I need?
If you choose a storage heater that is too small it’s likely you’ll continually be running out of hot water. At the other end of the scale, choose one that’s too big and you’ll waste money paying to heat water that you’re not even using.
Storage hot water heaters should be chosen according to household size. The more people in your home, the larger your storage tank should be. For households of 4 or more people, a gas storage system is usually the best option.
Instant systems (continuous flow) should be chosen according to the number of hot water outlets in the home, as opposed to the number of people. For lower usage, these systems work well.
Solar hot water systems should be chosen according to household size. So if you have a large household, a larger tank and more kW of solar panels will be required.
Which brand should I choose?
A number of brands sell systems that will efficiently and reliably provide hot water to your home. We don’t have a preference but some of the quality brands include Bosch, Rheem, Rinnai, Vulcan and Dux. At Quicksure Plumbing, we can replace or repair your existing system and install a new hot water system.
Please contact us if you have any questions or would like more information.