A lot of homeowners believe that hot water cylinders will run out of hot water or don’t have the capacity to handle the household usages and will require a lot of wait time to heat up. However if you’re storage tank is the correct size this should not be an issue.
The Cylinder Guy have put together a quick guide on the general rules of thumb you should follow to ensure that your hot water cylinder is the correct size for your household, so that you get hot showers all the time!
Unsurprisingly larger houses will require a larger hot water cylinder. When selecting your tank you should consider the number of occupants in your home and whether you have any additional needs outside of the average household. Generally every member of the household will require between 35 to 45 litres each. However some households on mains pressure can use up to 25 litres of water per minute! The personal preferences and habits of every member of the family should be consider. Some people might be more than comfortable with 35 litres, whilst others might use significantly more. As a general guide consider that;
Most household bath use around 100 litres, showers can use about 18 litres a minute. A high consumption user might use 100 litres or more a day. If you g off the average though you can probably expect your household to use about 200 litres from your hot water cylinder each day.
The water will be heated throughout the day however, so that does not necessarily mean you will need a 200 litre tank.
Why you should avoid buying too large
Some homeowners buy a larger tank than the calculations would suggest they need, usually to avoid having cold showers, but this actually wastes a lot of money and is less efficient.
Larger systems have larger upfront purchasing and installation costs and larger ongoing maintenance costs. Heating more than is required can increase bills and is wasteful, most professional installers will be able to recommend the best size or your family. To avoid unnecessarily large utility bills it is always a good idea not to supersize the system. Most systems will be able to comfortable keep up with the needs of your household.
Make sure you consider the climate where you live
An important point to be aware of when considering the size of your hot water cylinder. Colder areas will require more heating and might call for a higher capacity tank, whereas your consumption in a tropical climate will very likely be much lower! If you’re local area experiences particularly bitter winters or sharp seasonal changes you’ll want to prepare for the coldest months. If you’re buying in the summer make sure to account for increased consumption in the colder months because it will likely increase quite a bit, and you don’t want to get stuck with only enough for the hottest days of the year. Look back to your bills and consumption from the wintery parts of last year to get a more accurate picture of your usage.
Think about appliances that use water
Dishwashers, large washing machines and other household items can impact on your daily usage. Make sure you think through every household item that may be a drain on your hot water cylinder. You might have low average users in the household who only take short showers, but your wash cycle might use a lot from your system.
This is just a general guide to sizing and consumption, it’s always worth ask the manufacturer or installer for their recommendation.