If you are a homeowner in NSW using a traditional water heater, you must be paying huge bills for domestic […]
Key Takeaways
- Household Demand Matters Most
- Match the hot water system size directly to your household’s specific needs
- Larger families require larger systems
- Smaller households should avoid oversized units to prevent energy wastage
- Size Guidelines by System Type
- Gas Storage Systems:
- 1-3 people: 90 litre
- 2-4 people: 130 litre
- 3-5 people: 170 litre
- 4-6 people: 200 litre
- Solar Hot Water Systems:
- 1-2 people: 180 litre
- 3-4 people: 300 litre
- 5-6 people: 440 litre
- Heat Pump Water Heaters:
- Small (< 200L): 1-2 bedrooms, max 3 people
- Medium (200-300L): 3 bedrooms, minimum 4 people
- Large (300L+): 4+ bedrooms, 2+ bathrooms
- Gas Storage Systems:
How you can select the best heat pump hot water system.
1. Determine Your Household Hot Water Demand
The first consideration when picking your HPWH is the quantity of hot water needed in your home. If you have a larger family, you need a larger heat pump to meet the demand.
On the other hand, if you have a smaller household, you need a smaller one to avoid energy wastage. Ensure you match the unit’s capacity with your hot water needs.
2. Consider Energy Efficiency
Energy efficiency tells you how effectively the heat pump will convert electricity into hot water. The more efficient the unit, the less the electrical consumption and hence the utility bills and associated carbon footprint.
So, always go for a model boasting high energy ratings. Yes, it might cost you more, but it pays off in the long run.
3. Choose a Reliable Brand
Installing HPWH from a reputable brand means you can expect reliability in performance and durability. Besides offering highly energy-efficient systems, such a brand will also extend a reasonable warranty and other after-sale services, ensuring you are satisfied with your choice all the time.
4. Ease of Setting Up
You should always check the installation requirements when choosing an HPWH.
Some systems may need additional space or particular configurations. Others may necessitate additional accessories, which further adds to the costs. If you want to avoid such inconveniences, the only way is to choose an easy-to-install unit.
5. Evaluate Long-Term Costs
Don’t just focus on what you’ll pay for the unit up front; consider how much it will cost over time.
Models offering better efficiency and longevity may be more expensive upfront, but they will end up saving you money through energy bills and maintenance over the life of the unit.
6. Compare Maintenance Needs
How frequently will your HPWH demand attention? While it’s important to maintain the unit, you want one that can serve for a while without needing maintenance.
Get to know the precise maintenance duration (mostly, it’s 1 year in Australia) and figure out the costs to avoid frustration soon.
7. Noise Levels
When installing HPWH, look for those with reduced noise levels during operation. Such units will be easier to install indoors or closer to your house without creating noise discomfort.
A Step-by-step Guide to Determine Your Hot Water System Size
Now that you understand the importance of choosing the right size hot water system for your home let’s dive into a step-by-step guide to help you determine the perfect size.
- Calculate your household’s peak hot water demand. This would be at the busiest time of day when everyone is using hot water simultaneously. Consider activities like showering, running appliances, and washing dishes.
- Determine the degree of temperature increase needed by measuring the difference between the temperature of incoming cold water and the desired hot water temperature. Consider the climate and whether you’ll need a more extensive system to achieve the desired heating level.
- Evaluate the efficiency of different hot water systems. Look for models with high energy efficiency ratings to minimize waste and lower energy costs.
- Consider any future changes to your household. Are you expecting to expand your family or upgrade appliances? These factors can impact the size of the hot water system you’ll need.
Exploring Various Types and Sizes of Hot Water Systems
Now that you’ve grasped the importance of selecting the right-sized hot water system for your home and have a helpful guide to figure out the ideal size let’s dive into the different types and sizes available in the market.
Different households have specific needs, and luckily, hot water systems come in various sizes and types to meet these demands. The types you’re most likely to come across include storage tank systems, tankless systems, and heat pump systems.
Hot water size guide
Gas storage hot water system
| Household size | Gas storage hot water heater size |
| 1 – 3 people | 90 litre |
| 2 – 4 people | 130 litre |
| 3 – 5 people | 170 litre |
| 4 – 6 people | 200 litre |
An instant gas water heater can operate with natural gas or LPG. Its size isn’t determined by how many people live in the house but by how many faucets might need hot water at the same time.
For instance, if your home has two bathrooms and a kitchen that all require hot water simultaneously, particularly during peak times like the evening, you should consider acquiring a unit with a 24-litre capacity to guarantee an adequate supply of hot water for all the taps.
| Number of outlets | Gas instant hot water |
| 1 | 16 litre |
| 2 | 20 litre |
| 2 – 3 | 24 litre |
| 3 or more | 32 litre |
Solar hot water size guide
Solar hot water systems only heat water during the day. Most systems are fitted with either an electric or gas booster for high-demand times or overcast days.
| Number of people | Solar hot water system size |
| 1 – 2 | 180 litre |
| 3 – 4 | 300 litre |
| 5 – 6 | 440 litre |
Heat pump hot water size guide
Heat pump water heaters are very energy efficient, even more so if connected to an economy tariff (off-peak one or off-peak 2).
| Small – less than 200L | Medium – 200 – 300L | Large – 300L+ |
| Apartment or small house | Average sized house | Large house |
| 1-2 bedrooms & 1 bathroom | 3 bedrooms & 1 bathroom | Four or more beds & 2 or more baths |
| Maximum three people | It may not be suited to off-peak. Some can run on Restricted hours tariff | 4 or more beds & 2 or more baths |
| Not normally suited to off-peak tariffs | Minimum four people | Restricted hours and off-peak tariffs are possible |
The Importance of Choosing the Correct Size Hot Water System
Selecting the right size hot water system for your home is extremely important.
Why, you ask?
Well, if you’ve got the right size system, you’ll always have enough hot water for everything you need.
Be it for a warm bath, doing your laundry, or tackling that pile of dishes; a suitably sized system means you don’t have to deal with unexpected cold shocks.
Second, picking a system that fits your needs is essential for optimizing energy efficiency. If your water heating system is oversized, it will consume more energy than needed, leading to expensive energy bills.
On the other hand, a too-small system will have to strain to satisfy your hot water needs, resulting in heightened energy usage.
Lastly, the correct size hot water system also ensures adequate water pressure. If your system is too large, it can put unnecessary strain on your pipes and fixtures, leading to reduced water pressure.
Understanding Different Factors That Influence Hot Water System Size
Determining the size of your hot water system involves several factors to keep in mind. Consider the size of your household, how many bathrooms you have, the number of people using water simultaneously, and your day-to-day hot water usage.
It’s crucial to remember just how important water is in our daily homes. Think about those busy mornings when everyone’s trying to get ready for work or school. It’s during these times that the water demand is at its highest.
Therefore, having a hot water system that can cope with these high-peak demands without running out is of utmost importance.
Also, don’t forget to account for the degree of heating needed. This means figuring out the gap between the current water temperature and the desired water temperature.
If you reside in a cold area where you usually need to heat water considerably, it’s crucial to select a system that can effectively meet this need.
It’s also a good idea to consider how efficient your chosen hot water system is. Look for ones that have high energy efficiency ratings. This way, you can be sure you’re not wasting energy and keeping your costs low.
Finally, think about any changes in your home that could affect how much hot water you use.
Are you expecting new household members? Or do you plan on adding an extra bathroom or replacing your old appliances? These things can influence the size of the hot water system you’ll need.
Avoid These 5 Common Mistakes When Selecting a Heat Pump Hot Water System
No matter how hard selecting an appropriate HPWH may be for you, never make any of the following mistakes:
1. Hiring an Unqualified Installer
Being a recent technology, your heat pump needs proper positioning and configuration to serve as intended.
It also needs to be placed in the right spot – either indoors or outdoors, as determined by experts.
If you hire unqualified installers, they will do shoddy work, leading to regular unit breakdown, improper function, and reduced lifespan.
2. Choosing the Wrong Size
Your family’s hot water needs should match your HPHW capacity. If you mismatch the two, you’ll end up with a different problem.
Choosing under size — It would mean less hot water. You might have to heat too frequently and this means more bills.
Choosing oversize — You will be heating more water than needed resulting in energy wastage.
NB: When choosing the correct size, also consider the recovery rate. A small unit with a high recovery rate may be better than some larger units.
3. Ignoring Your Local Climate
Heat pumps draw heat from the air instead of generating it directly. They work best in regions boasting higher temperatures than those with cold climates.
You should therefore consider your climatic condition before buying. If your climate is a bit colder, choose an HPWH with a backup heating element.
4. Overlooking Installation Guidelines
Failure to follow any installation guidelines can lead to inefficiency and safety risks.
Always confirm that the system is installed according to the manufacturer’s instructions.
Proper installation will protect your investment and ensure safe operation.
5. Going for the Cheapest Option
Going for a cheaper option will only save you money at the very start of buying the system, but will cost you eventually.
According to experts’ observations, most cheap systems break down faster and consume more energy.
So, it’s better to invest in a high-quality unit that will last and save you over time.
Final Thoughts
Storage tank systems are the traditional choice, where hot water is stored in a tank for immediate use. These systems come in various sizes, ranging from small tanks suitable for apartments to large tanks for big households.
As discussed in our guide, you can determine the right size heating system for your household by considering peak demand, desired heating level, system efficiency, and the future needs of your household.
