Calculating Your Hot Water Usage

The first step to take in choosing a new hot water system is to calculate the hot water usage in your home. The amount of hot water each household uses will vary depending on lifestyle, appliances, and water fixtures throughout the house.

How many people will be using the hot water system?
- You should count the number of people living in your home full time, but also consider how often you have visitors coming to stay.
How many showers or other outlets will the system be attached to?
- If you only have one shower attached to your hot water system, then the system may have more time to heat more water for subsequent showers, which means a smaller heater may be suitable.
The type of shower heads you use in your bathrooms.
- We all know those households with teenagers will probably use more water than average, but did you know that the shower heads you have installed can also impact your hot water usage?
- Older, standard shower heads typically use around 20 litres of water per minute. A 10-minute shower would average 200 litres per day, per person.
- It may be worth considering switching to a water-saving shower head. You can reduce the amount of water used to around 9 litres per minute. This is around less than ½ of the previous amount used...not only will you reduce your hot water usage, but you will probably notice a reduction in your water bill!
Whether your family has more showers or baths.
- How your family bathes can have a huge impact on your water usage.
- The average bath in Australia uses around 95 litres of water. This is less than a 10-minute shower with a standard shower head and on-par with a water-saving shower-head.
How you wash your dishes
- According to a study by the University of Bonn, the average amount of water a person uses to wash their own dishes by hand every day is 10.5 litres. With the average household in Australia being 2-3 people, washing your dishes by hand would use between 21-31.5 litres a day.
- An average dishwasher uses approximately 15 litres of water per cycle.
How often you do laundry
- This will greatly depend on the type of washing machine you have. Many, if not most, modern machines will only need to have cold water running into them and so won't impact upon your hot water usage. We recommend checking your washing machine installation and whether or not it has a hot water feed in.