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Introduction to Hot Water System Sizing

Selecting an appropriately sized hot water system for your Sydney home, especially in Balmain, is crucial. A system that’s too small might not meet your needs, leading to inefficiency and lack of hot water. Conversely, a system that’s too large will incur higher purchase and operational costs due to excess water heating.

The correct size ensures your system meets your hot water needs consistently, reducing water and energy consumption.

Choosing the right size for your hot water system involves considering key factors such as:

  • Number of household members
  • Number of bathrooms
  • Peak usage times
  • Appliance use - dishwasher, washing machine
  • Power source - off-peak vs peak tariffs

Various hot water systems, including electric, gas, solar, and heat pumps, are available, each with sizing guides to cater to your daily water usage. It’s essential to consider the number of people in your home to determine the correct tank size or flow rate required.

Balmain Plumbing specialists can assess your needs and recommend the most efficient hot water system size for your home.

Determining Your Household’s Hot Water Usage

Selecting a hot water system means assessing your household’s daily hot water needs. This assessment informs the capacity your system will require.

The average Australian household consumes roughly 70 litres of hot water per person each day. For a family of four, this amounts to about 280 litres required from your hot water system daily.

To calculate the hot water volume needed for each person in your home, consider the following 'what size hot water system do I need’ guide:

  • Count the number of people your household
  • Multiply by 70 litres per person
  • Add extra capacity for high-use appliances like dishwashers and washing machines
  • Factor in peak usage times when hot water demand spikes, usually mornings and evenings

The following capacities are general recommendations for residential hot water systems:

  • 1-2 people - 125 litre storage tank
  • 3-4 people - 160 to 250 litre storage tank
  • 5+ people - 300+ litre storage tank, or a tankless water model

Balmain Plumbing can evaluate your hot water needs and suggest the most suitable system capacity.

Types of Hot Water Systems and Size Considerations

When choosing the suitable hot water system size, consider these common types:

Electric Storage

A storage hot water system, whether electric, gas, or using alternative fuels, features insulated tanks to heat water. Hot water systems are available in various capacities to meet individual needs:

  • 50-80 litres - 1-2 people
  • 125-150 litres - 3-4 people
  • 250+ litres - 5+ people

Households with substantial hot water usage should consider multi-unit electric systems or combined heat pump and gas solutions to meet their needs.

Gas Storage

Gas storage hot water systems efficiently heat water using natural gas burners. Here are the typical sizes based on usage:

  • 16 litres per person
  • Add extra capacity for dishwashers, washing machines, etc.

For selection, consider a 170-litre unit for 3-4 people, or a 270-litre unit for households with 5 or more.

Instantaneous/Continuous Flow

Instantaneous hot water systems can offer warmth on-demand, eliminating the need for a storage phase. The flow rate, measured in litres per minute, should be sufficient for peak usage:

  • 16-20 LPM - 1 bathroom
  • 20-26 LPM - 2+ bathrooms

Solar and Heat Pump Systems

Solar heat pump hot water systems, including their hybrid variants, are sized with local climate influences and household needs in mind. Speak to our experts about options.

Future changes to your household or hot water needs may require resizing your system. The professionals at Balmain Plumbing are adept at determining the right size your hot water system requirements, keeping in mind both current and future necessities.

Electric Hot Water Systems

An electric hot water system uses electric elements to warm water in an insulated storage tank, commonly in these sizes:

  • 50-80 litres – Suits 1-2 people
  • 125-150 litres – Suits 3-4 people
  • 250+ litres – For 5+ people, consider multiple tanks or alternate system types

Benefits of electric systems include:

  • Lower upfront costs than gas or solar
  • Simple maintenance
  • Established technology, easily serviced

Key factors for sizing include:

  • Optimal for smaller households
  • Higher running costs than gas or solar
  • Limited scalability for larger demands

The experts at Balmain Plumbing can suggest the right hot water heater dimensions for your home’s needs while enhancing efficiency.

Gas Hot Water Systems

Gas hot water systems harness natural gas or LPG burners to rapidly heat water within insulated tanks, usually necessitating smaller tank sizes when compared to electric heaters.

As a general guide for gas storage water unit:

  • Allow 16 litres per person capacity
  • Add extra capacity for high-use appliances
  • For a duo, an appropriate water system size 1-2 people might be in the realm of 170 litres
  • A 270 litre system suits 5+ people

Benefits of gas hot water systems include:

  • Lower running costs than electric
  • Faster water heating
  • Smaller units can suffice due to faster recovery

Important factors to consider when sizing gas systems:

  • Higher upfront costs
  • Need adequate gas supply and fluing
  • Regular compliance checks required

The professionals at Balmain Plumbing can assess your household’s needs and recommend the most efficient gas hot water system size.

Solar Hot Water Systems

Solar hot water systems use free heat from the sun to warm water. Solar collectors, usually roof-mounted panels, harness sunlight to heat water stored in an insulated tank.

When determining the size of a solar water heating system, take into account:

  • Average daily household hot water usage
  • Home solar exposure based on orientation, shading, and climate
  • Tank size to store adequate hot water
  • Electric or gas backup to supplement on cloudy days

Benefits of solar hot water systems:

  • Lower greenhouse gas emissions
  • Reduce energy bills by up to 60%
  • Government rebates available
  • Minimal maintenance required

Considerations when sizing:

  • Limited usefulness for homes with low solar access
  • Potentially more expensive initial investments compared to electric or gas options
  • May need conventional system backup

The team at Balmain Plumbing can assess your home’s solar potential and hot water requirements to recommend the optimally sized solar hot water system.

Heat Pump Hot Water Systems

Heat pump hot water systems are an energy efficient choice using heat extraction technology. For residential applications, the key factors affecting size selection are:

  • Average daily household hot water demand
  • Ambient air temperature based on climate and location
  • Desired water temperature at delivery and associated flow rates
  • Physical space available for installation

As a benchmark, a typical 250 litre heat pump system attached to a standard 180 litre storage tank delivers enough hot water for a 3-4 person household. Larger households may benefit from multiple linked heat pump water heaters.

Benefits of heat pump hot water heaters include:

  • Very high energy efficiency, lower running costs
  • Environmentally-friendly with 60%+ less CO2 emissions
  • Eligible for renewable energy certificates
  • Deliver hot water in any weather

Considerations for sizing include:

  • Higher upfront purchase and install costs
  • Require adequate airflow so outdoor unit placement affects choice
  • Optimal efficiency with regular use to minimise standby losses

The team at Balmain Plumbing can recommend the appropriately sized heat pump system for your home’s specifications and hot water requirements.

Installation and Maintenance Considerations

When installing a new hot water system, ensure that it’s placed strategically for convenient future maintenance.

Location and Space Requirements

Ensure there is ample space around the tank and any external units, facilitating:

  • Convenient access for repairs
  • Sufficient airflow to maximise efficiency

Outdoor units such as heat pumps should be shielded from the elements and must comply with noise regulations that demand more than simple placement.

Planned Preventative Maintenance

Plan annual inspections of your water heater to:

  • Inspect components and connections
  • Clean filters and sensors as needed
  • Confirm correct operation
  • Extend system lifespan

When positioning new units, consider both the type and size of the water system you need and the ease of access for maintenance. Consult the professionals at Balmain Plumbing to ensure optimal installation for performance and longevity.

How We Can Help Select Your New System

The experts at Balmain Plumbing can help guide you through the entire process of selecting the best hot water system for your home.

We begin with a thorough assessment of your household’s specific needs and expected hot water demand. This includes factors like:

  • Number of residents
  • Bathrooms, showers, and other hot water outlets
  • Peak usage times
  • Appliance use
  • Space constraints
  • Budget

We establish which hot water system – be it electric, gas, solar, or heat pump – provides the necessary capacity and optimises efficiency and cost savings for your situation.

With over thirty years of expertise, we are well-equipped to accurately determine the proper size for your hot water system, addressing both current and future requirements. We handle the full installation using premium materials for reduced maintenance, with all workmanship guaranteed.

To access personalised advice on selecting your next hot water system, email the team at Balmain Plumbing or call 1300 349 338 to book your in-home consultation.

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