The Ultimate Guide to Heat Pump Hot Water Systems: How They Work, Their Longevity, and Energy Efficiency

Tired of sky-high energy bills? Looking for a more eco-friendly hot water service? Wondering if heat pump hot water systems are worth it? We’re to answer all of your burning questions.

In a recent Canstar Blue study, it was found that hot water accounts for approximately 25% of the average household power bill (Source: ABC Australia). These figures underscore just how important hot water efficiency can be.

Heat pump hot water systems represent one of the most significant advancements in residential water heating technology. Unlike traditional electric or gas water heaters, heat pumps harness renewable energy from the surrounding air, with some systems found to be up to 78% more efficient.

Throughout this comprehensive guide, we’ll cover everything you need to know about heat pump hot water systems—from how they work to installation requirements and cost analysis.

Understanding Heat Pumps

Heat pumps operate much like your refrigerator—but in reverse. Rather than removing heat from an enclosed space, they extract warmth from the surrounding air and transfer it to water.

Essentially, a heat pump is a device that moves heat from one place to another using a small amount of energy. This represents a stark contrast to gas based systems that burn fuel to generate heat.

In this case, it uses electricity to capture heat that already exists in the environment. This process makes heat pumps incredibly efficient compared to conventional heating systems. Even in cooler temperatures, there’s still ambient heat in the air for these systems to harness.

Heat pump technology represents a significant shift from traditional water heating methods, particularly in regards to sustainability and energy consumption.

What Is a Heat Pump?

A heat pump is a mechanical system that transfers thermal energy from a cooler space to a warmer environment. Once operational, the pump uses a refrigeration cycle to reverse this natural flow, extracting heat from the air, ground, or water and concentrating it for useful purposes (such as heating water).

The technology behind heat pumps isn’t new. What’s really changed, however, is the overall efficiency and reliability of these systems. More advanced heat pumps, such as the Wilson Aqualux series, are highly effective even when outdoor temperatures drop well below freezing (as low as -25°C).

In the context of hot water systems, heat pump technology has become an energy-efficient alternative to traditional water heaters. Because they tap into the renewable heat sources all around us, these systems have become a great way to reduce both energy consumption and greenhouse gas emissions.

The process works like this: The evaporator pulls heat from the air while the refrigerant absorbs this heat and turns from liquid to gas. The compressor then pressurises this gas, raising its temperature significantly—much like how a bicycle pump gets warm when you inflate a tire.

The hot, pressurised refrigerant passes through the heat exchanger wrapped around the water tank. Here, the heat transfers to the water while the refrigerant cools and returns to liquid form. Finally, the expansion valve reduces the refrigerant’s pressure, cooling it further before it returns to the evaporator to begin the cycle again.

Heat Pumps vs. Traditional Hot Water Units: Why Are Hot Water Heat Pumps Energy Efficient?

When we compare heat pumps to more conventional electric water heaters, the difference is stark. Why? Traditional electric systems use heating elements (essentially large resistors) to convert electricity directly into heat. This is inherently inefficient, with a coefficient of performance (COP) of just 1.0, meaning one unit of electricity produces one unit of heat.

Heat pumps, on the other hand, typically achieve COPs between 3.0 and 5.0. Leading models (including the Wilson Aqualux models can achieve an impressive COP of 4.52 under standard conditions, meaning they produce over four units of heat using just one unit of electricity—the rest comes free from the environment. This translates to energy savings of up to 78% compared to conventional electric systems.

Gas systems fare somewhat better than electric resistance heaters in terms of running costs but still can’t match the efficiency of heat pumps. Plus, they produce carbon emissions directly during operation.

Heat pumps also offer significant advantages from an environmental standpoint. Even when powered by grid electricity, their exceptional efficiency naturally translates to lower overall emissions, even more so when paired with solar panels.

How does this all look in real terms? Referring to the graph from Sustainability Victoria to illustrate why hot water heat pumps are so energy efficient . As you can see, both the ongoing costs and greenhouse gas emissions are significantly lower when a heat pump system is operating. These figures were based on an average 4 person household in Victoria.

These calculations should be used as a guide only. Your water heating energy costs will depend on:

• The amount of people in the household
• How hot water is used
• Energy tariffs
• The climate
• System efficiency
• Length and insulation of connecting pipes
• Flow rates (water efficiency) of taps and showers.

How Does a Heat Pump Hot Water System Work?

At its core, a heat pump hot water system works by extracting ambient heat from the surrounding air and transferring it to your water supply. This process is far more energy-efficient than generating heat directly through electrical resistance or combustion.

The Science Behind Heat Transfer

The process ultimately relies on the basic principles of thermodynamics.The refrigerant within the system has a very low boiling point, and this is what allows it to absorb heat energy and transition from liquid to gas.

As this gas is compressed, its temperature rises significantly—following a similar principle that when a gas is compressed, the temperature increases. This highly efficient process is what allows heat pumps to achieve their remarkable energy efficiency ratios.

What Is a Heat Pump Hot Water System?

A heat pump hot water system combines heat transfer technology with a water storage tank. Unlike instant water heaters that generate heat on demand, heat pump systems work continuously at a steady, efficient pace to maintain a tank of hot water that’s ready for use.

The Wilson heat pump models come with a split system design that separates the heat pump unit from the storage tank. This provides greater installation flexibility and allows the tank to be located indoors, while the heat pump unit remains outside where it can access abundant air flow.

A New Generation of Heat Pump Systems

The technology behind heat pump hot water systems has evolved significantly in recent years. These advancements have dramatically improved efficiency, reliability, and user experience. Let’s take a look:

Cutting-Edge Components

Inverter Compressor Technology

Unlike fixed-speed compressors that constantly turn on and off, inverter compressors (such as the Mitsubishi inverter compressors used in the Wilson Aqualux system) have the capacity to vary their operational speed to match demand. This results in:

• Lower energy consumption
• Reduced wear on components
• Significantly quieter operation
• More consistent water temperature

Variable Speed Fan Motors

DC fan motors that operate at variable speeds offer an array of different benefits, including:

• Minimised noise and vibration
• Optimised airflow for maximum heat extraction
• Lower energy consumption while maximising hot water production

Electronic Expansion Valves

These components allow for precise control over refrigerant flow, working in conjunction with the system’s microprocessor to:

• Maximise hot water production efficiency
• Minimise energy consumption
• Deliver consistently high Coefficient of Performance

Double-Layer Stainless Heat Exchangers

Advanced heat exchanger designs provide:

• Maximum protection from refrigerant entering the water system
• High-efficiency heat transfer to water
• Superior durability and longevity

Automated Safety Systems

Finally, features like built-in air exhaust valves allow for continuous operation even if air enters the system.

Smart Control Systems

Much like air conditioning systems, newer heat pumps are increasingly incorporating intelligent control systems designed to improve efficiency, as well as the overall user experience.

Digital Interfaces

User-friendly touch screens offer easy access to:

• Temperature settings
• Operating modes (Powerful, Smart, Silent)
• Timer functions
• System status information

Multiple Operating Modes

Premium systems like the Wilson Aqualux offer different operation profiles to suit various needs:

• Performance mode for maximum output
• Economy mode for optimal efficiency
• Silent mode for noise-sensitive times or locations

Smart Connectivity

Advanced models feature wireless connectivity that enables:

• Remote monitoring via smartphone apps
• System notifications and alerts
• Remote software updates for improved performance
• Integration with home automation systems

Heat Storage Functionality

Intelligent systems can store heat during optimal times (such as during daylight hours when solar panels are producing electricity), maximising energy efficiency and reducing operating costs.

Interested to learn more? Follow this link and discover the Wilson difference today!

Natural Refrigerant R290: The Future-Proof Solution

Environmental impact is becoming an increasingly important consideration for homeowners, which is why so many Australians are looking beyond the traditional options. One of the key factors influencing the capacity and efficiency of heat pump systems is the refrigerant used.

R290 (propane) refrigerant, a core component of the Wilson Aqualux series, is becoming more popular due to its exceptional environmental profile and excellent thermodynamic performance. Unlike many conventional refrigerants, an R290 refrigerant is:

To put it in perspective, this is how R290 compares to other common refrigerants:

With regulatory changes increasingly limiting the use of high-GWP refrigerants, R290 represents a future-proof solution that delivers excellent performance while minimising environmental impact.

ECO FACT: R290 refrigerant has a global warming potential (GWP) of just 3—that’s nearly 700 times less impact than common refrigerants used in older systems!

Engineered for Peace of Mind: Noise Reduction Technology

One of the most common concerns many people have about heat pump hot water systems is noise. The good news is that with advancements in design and manufacturing, newer models have incorporated sophisticated noise reduction features that make them quieter than ever before.

In the Aqualux series, Wilson has been able to achieve decibel levels as low as 39dB(A) at 1 meter—about the same as a quiet library. This is achieved through:

How Much Does a Hot Water Heat Pump Cost? Average Costs and Pricing Considerations in Australia

Investing in a heat pump hot water system involves considering the initial cost, potential rebates, and long-term savings. Prices and incentives will vary across different areas of Australia, so always do some research into your specific situation.

High-Quality Heat Pumps in Australia vs. Cheap Alternatives: Why the Cheap Ones Don’t Work Well – Beware of Rebate Scams

While it may be tempting to go with the cheapest option on the market, this can be quite a costly mistake. This is because lower-priced heat pumps often use inferior components, leading to:

Although the upfront cost may be initially higher, leading Australian manufacturers supply systems with far greater efficiency, reliability, and ongoing performance.

Beware of “rebate scams” where installers inflate the price of a cheap system to claim a large rebate, leaving you with a substandard product. Always get multiple quotes and choose a reputable installer.

Rebate Rules in Different States

From climate change to cost-of-living, there are many reasons to make the switch. The good news is that there are government rebates on offer to ease the financial burden.

The rebates available do vary considerably between states. Here’s a brief overview:

These are just general examples, and specific rules and rebate amounts change regularly. It’s important, therefore, to check the relevant government websites and consult with your installer for the most up-to-date information.

If you’re planning to buy a domestic Wilson heat pump system, be sure to use our free online tool to find rebates that apply to your local postcode.

Hot Water Solar System Price vs. Heat Pump Hot Water System Price

Traditional solar hot water systems (with roof-mounted panels) often have a higher upfront cost than heat pumps, typically ranging from $3,000 to $7,000 installed. While solar hot water can be very efficient in sunny conditions, heat pumps offer more consistent performance regardless of weather and can be a more cost-effective option in many cases.

Disclaimer: The prices listed are general estimates and can vary based on factors such as system size, brand, installation complexity, and location. Additional costs may apply for plumbing modifications, electrical work, or permit requirements. For an accurate quote, consult with a licensed dealer in your local area.

Return on Investment and Long-Term Savings

While the initial investment in a heat pump hot water system is higher than a conventional electric storage system, the significantly lower running costs lead to a relatively quick payback period, typically within 3-5 years. After this, you’ll continue to enjoy substantial savings on your energy bills for the life of the system (10-15+ years).

Systems with higher efficiency ratings, like Wilson’s Aqualux with its COP of 4.52, can offer even faster payback periods due to their superior energy performance.

Installation and Maintenance

As with any appliance, proper installation and regular maintenance are the best way to get the most out of your heat pump hot water system.

Sizing and Performance

Choosing the right size heat pump hot water system is crucial for ensuring adequate hot water supply and maximising energy efficiency.

What Size Heat Pump Hot Water System Do I Need?

The appropriate size depends on several factors:

• Household size: The number of people in your home.
• Hot water usage: Your typical daily hot water consumption.
• Climate: Colder climates may require a larger or more powerful system.
• Usage patterns: Do you have high peak demands (e.g., multiple showers at the same time)?

A general guide is:

• 1-2 people: 160-200 litre system
• 3-4 people: 250-315 litre system
• 5+ people: 315-400 litre system

Premium manufacturers like Wilson offer tanks in these exact size ranges (160L, 250L, 315L) to match different household needs. Still finding yourself asking the question of “what size heat pump hot water system do I need?”, well, it’s always best to consult with a qualified installer to find a model that best suits your space, capacity, and household size.

Comparing Hot Water Pumps

As you assess the different models, consider these key performance indicators:

• COP (Coefficient of Performance): Higher is better. Premium models like Wilson Aqualux achieve 4.52 under standard conditions.
• Noise levels: Measured in decibels (dB). Lower is better. The best models operate at around 39dB.
• Operating temperature range: Wider is better. Leading systems can operate from -25°C to 45°C.
• Maximum water temperature: Higher temperatures provide more usable hot water. Top systems can deliver water at 60-63°C.
• Tank warranty: Longer is better. Premium systems offer 10-year tank warranties.
• Heat pump warranty: Longer is better. Quality systems typically offer 6-year warranties.
• Does the unit have an electric element: This is another important factor to consider

Heating Water Pump Efficiency and Savings

As household bills become higher than ever, everyone can benefit from upgrading to more energy efficient hot water systems.

The efficiency of a heat pump is measured by its Coefficient of Performance (COP). A higher COP means greater efficiency. Heat pumps typically have COPs ranging from 3.0 to 5.0, meaning they produce 3 to 5 units of heat for every unit of electricity consumed. This translates to significant energy savings compared to conventional electric water heaters.

When selecting a system, look for those with higher COP ratings under a range of operating conditions, not just optimal conditions. The most efficient systems, like those in the Wilson Aqualux series, maintain good efficiency even in challenging weather conditions.

When to Consider a Larger or Smaller Unit

• Larger unit: If you have high hot water demands, frequent guests, or plan to expand your household, consider a larger unit. Premium manufacturers offer sizes up to 315L for larger households.
• Smaller unit: If you have low hot water usage and a small household, a smaller unit (such as 160L) may be sufficient and more cost-effective.

Performance, Durability, and Troubleshooting

Let’s now transition into a breakdown of the many functional aspects of a heat pump hot water system.

How Long Do Heat Pump Hot Water Systems Last?

A well-maintained heat pump hot water system typically lasts for 10-15 years, or even longer in certain circumstances. The lifespan can be influenced by factors such as:

• Water quality: Hard water can affect system components
• Usage patterns: Heavier usage may lead to faster wear
• Maintenance practices: Regular servicing extends lifespan
• Component quality: Premium components (like those in Wilson systems) typically last longer
• Environmental conditions: Extreme conditions may impact longevity

Leading manufacturers back their confidence in their products with comprehensive warranties. For example, Wilson heat pump systems come with a 6-year warranty on the heat pump components and up to 10 years on the tank.

Do Heat Pump Hot Water Systems Work in Cold Weather?

If you live in a location with a cooler climate, such as Victoria, ACT, or Tasmania, a common question you might have is “do heat pump hot water systems work in cold weather?” The answer? Yes, of course.

New heat pumps are designed to operate efficiently in a wide range of temperatures. Many quality models will also function effectively even when operated in sub-zero conditions. For example, the Wilson Aqualux series is engineered to operate in temperatures as low as -25°C, making it suitable for even the coldest Australian winter conditions.

However, it’s still worth noting that efficiency may decrease in extremely cold weather. Luckily, some models come with a booster element that helps to deliver an adequate hot water supply in these more extreme circumstances. Since these conditions are rarely seen in Australia, this isn’t too much of a concern.

Can a Heat Pump Hot Water System Be Installed Indoors?

The vast majority of heat pump hot water systems are designed for outdoor installation. This is because they require adequate ventilation to draw in and expel air. However, some models, particularly split systems like the Wilson Aqualux, can have the tank installed indoors while the heat pump unit remains outside, which ultimately allows for greater installation flexibility.

Dealing with Noise, Space, and Climate Challenges

• Noise: Modern heat pumps are generally much quieter than older models. Premium systems like the Wilson Aqualux operate at just 39dB (measured at 1 meter), about the same as a library whisper.

NOISE: 39dB is quieter than a normal conversation (60dB) and even the average household fridge (40dB). Noise-optimised heat pumps will operate day and night without any disturbance to your household or neighbours.

• Space: Heat pumps require adequate space for installation and airflow. Make sure that you have sufficient clearance around the unit as specified by the manufacturer.

Climate: Choose a system designed for your specific climate zone. In Australia, look for systems with wide operating temperature ranges like -25°C to 45°C for the best year-round performance.

Electric Heat Pump Hot Water System vs. Gas Alternatives

Heat pumps offer several advantages over gas hot water systems. Most notably these include:

• Higher efficiency: Heat pumps are generally more energy-efficient than gas systems.
• Lower greenhouse gas emissions: Heat pumps produce fewer emissions, especially when powered by renewable energy.
• Safety: Heat pumps do not involve combustion, eliminating the risk of gas leaks or carbon monoxide poisoning.
• Renewable Energy: Can connect to Solar PV.
• Rebates: The chance to reduce installation costs with government rebates.

What Is the Best Heat Pump in Australia?

Once you’ve decided to go with a heat pump hot water system, the next step is to compare the different options available. Here’s how some of the top contenders in the Australian market compare:

Top Heat Pump Brands Comparison:

The right choice boils down to your specific circumstances, be it the household size, climate, budget, and general hot water demands. However, we do recommend considering everything  from long-term value to energy efficiency, technological features, durability, sustainability, and warranty coverage.

Warranty and After-Sales Support

As you explore the various heat pump hot water system options, always keep an eye out for warranty coverage and after-sales support. For example, you can consider all of the following aspects:

• Component Coverage: Look for differentiated coverage that provides longer protection for the most expensive components.
• Tank Warranty: Since the tank represents a significant portion of the system cost, longer tank warranties provide valuable long-term protection. Wilson offers a 10-year tank warranty (excluding WA).
• Manufacturer Heritage: Companies with long-standing presence in the Australian market (like Wilson with 90+ years) are more likely to honor warranty commitments and provide spare parts throughout the system’s lifetime.
• Service Network: Nationwide service availability ensures that warranty claims and maintenance needs can be addressed promptly, minimising downtime.

While evaluating the product’s warranty, be sure to read the fine print regarding installation requirements, as improper installation may void warranty coverage.

Sustainability and Peace of Mind

Sustainability is, without a doubt, one of the key reasons so many Australians are making the switch to more energy efficient hot water systems. As we all experience the effects of climate change, the ability to invest in more eco-friendly household appliances has become more important than ever.

Extreme Climate Compatibility

Wilson Aqualux tanks have been tested in line with AS 2515 standards and are proven to operate safely in Australia’s harshest conditions:

• Wide temperature range: Operation from -25°C to 45°C ensures reliable performance year-round in all Australian climates.
• Weather-resistant construction: Robust outdoor units withstand sun, rain, and varying weather conditions.
• Anti-freezing protection: Built-in safeguards prevent damage in freezing conditions.

Multiple Operating Modes

The more advanced the system, the more user-friendly it is likely to be. This includes different operating functions to suit various needs, including:

• Low noise modes for quiet operation near living spaces
• Performance modes for maximum efficiency and output
• Automatic modes for optimal balance of performance and energy use

Warranty Coverage

Comprehensive warranty packages provide peace of mind:

• Heat pump units: Typically 5-6 years warranty coverage
• Storage tanks: Up to 10 years warranty on premium models
• Manufacturer support: Established companies with longstanding Australian presence provide reliable after-sales support

By choosing systems with these sustainability and reliability features, you’ll not only enjoy substantial energy savings but also the assurance of dependable hot water for many years to come.

The Ultimate Guide to Heat Pump Hot Water Systems: Final Thoughts

Summary of Key Benefits

Heat pump hot water systems offer a compelling range of advantages for Australian households. Most notably, these include:

• Energy Efficiency: They can use significantly less electricity than conventional electric systems, reducing your energy bills.
• Environmental Impact: These systems have a lower carbon footprint, particularly when combined with renewable energy sources like solar panels.
• Long-Term Savings: While the initial investment might be higher, the long-term savings often result in a relatively short payback period, followed by continued cost reductions.
• Reliability: High-quality systems are designed to provide many years of dependable service, offering a worthwhile long-term investment.
• Performance: They deliver consistent hot water in most Australian climate conditions.
• Government Support: Rebates and incentives are often available in many states, making the initial investment more affordable.

At Wilson, we’re proud to produce the best hot water heat pumps on the market today. Our Aqualux series comes with excellent efficiency, proven cold-weather performance (operating down to -25°C), reduced noise levels (as low as 39dB), and smart features for the ultimate level of convenience.

The Aqualux R290 (our signature model) also features innovative Mitsubishi inverter compressors, variable-speed fans, low noise levels, and an environmentally friendly R290 refrigerant.

Take the Next Step with Wilson

Ready to turn your search into a reality with a Wilson heat pump hot water system? Here’s a straightforward plan to guide you:

Your Heat Pump Hot Water System Action Plan:

1. Assess Your Needs:
   • Determine the number of people in your household and estimate your typical hot water usage.
   • Identify peak usage times (e.g., morning showers, evening baths).
   • Consider any special requirements, such as large bathtubs or multiple bathrooms.
2. Research Rebates and Incentives:
   • Check your state government’s websites for energy efficiency programs.
   • Contact your energy provider to inquire about any additional incentives they may offer.
   • Familiarise yourself with eligibility criteria and the application procedures
   • Calculate government rebates in your local area with Wilson.
3. Get Quotes from Reputable Installers:
   • Contact several qualified installers for quotes and advice.
   • Ask about their experience with heat pump installations.
   • Inquire about available rebates and promotions.
   • Discuss various installation options and requirements.
4. Prepare for Installation:
   • Ensure clear access to the installation area.
   • Consider the optimal location for the unit to maximise efficiency and minimise noise.
   • If possible, schedule the installation during off-peak hours.
5. Establish a Maintenance Routine:
   • Schedule regular professional servicing, ideally annually.
   • Familiarise yourself with basic maintenance tasks you can perform as the owner.
   • Keep the manufacturer’s documentation handy for reference.

FAQs and Additional Tips

How Do Heat Pump Hot Water Systems Work?

Heat pumps work by extracting heat from the surrounding air and transferring it to the water in the storage tank. They use a refrigeration cycle similar to that of a refrigerator, but in reverse. This process is highly efficient because it moves heat rather than generating it directly.

How Much Energy Does a Hot Water Heat Pump Save?

Heat pumps can save up to 78% of energy compared to conventional electric water heaters. The exact savings depend on factors such as the system’s efficiency, your hot water usage, and your climate. Premium models with high COP ratings (like the Wilson Aqualux with 4.52 COP) deliver the greatest savings.

Are Heat Pump Hot Water Systems Worth It in the Long Run?

Absolutely! Heat pumps are both durable and suitable for most households. Of course, you’ll always want to invest in a brand that offers long-term warranty coverage, as well as a demonstrated track record for manufacturing high-quality products.

Could a Heat Pump Replace My Existing System?

In most cases, a heat pump can replace an existing electric or gas hot water system. However, a qualified installer should assess your specific situation to ensure a smooth transition. Split systems like the Wilson Aqualux offer greater installation flexibility, with separate heat pump and tank components that can be positioned for optimal performance and convenience.