Guide to Retrofit Commercial Heating and Hot Water Solutions

We focus on retrofitting heating and hot water energy intensive building systems, traditionally powered by gas.

In today's rapidly changing energy landscape, Automatic Heating is leading the charge in transforming traditional gas-powered heating and hot water systems to sustainable, electric solutions.

As the world grapples with the urgent need to reduce carbon emissions, the move towards electrification is not merely a trend—it's an imperative. This guide delves into the intricacies of retrofitting heating systems, offering insights into the challenges, solutions, and the innovative offerings by Automatic Heating.

Whether you're a building manager, an engineer, or simply an advocate for sustainable solutions, this guide provides a roadmap to understanding and implementing retrofit heating solutions for a greener future.

Need help with Retrofit Heating Systems?
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Need help with Retrofit Heating Systems?

Request a call back from one of our technical support staff.

Why Retrofit?

Retrofitting is not just an environmental imperative; it's a smart business decision. As global efforts intensify to achieve Net Zero carbon emissions, retrofitting existing buildings to be more energy-efficient is pivotal. But beyond the environmental benefits, retrofitting offers tangible economic advantages:

  • Cost Savings: While there's an initial investment, retrofitting can lead to significant long-term savings. Energy-efficient systems often mean reduced operational costs, and with the rising prices of non-renewable energy sources, the savings can be substantial over time.
  • Increased Property Value: Energy-efficient buildings are increasingly in demand. A retrofit can enhance the value of a property, making it more appealing to potential buyers or tenants who prioritise sustainability and reduced utility bills.
  • Operational Efficiency: Modern electric systems often require less maintenance than older, gas-powered systems. This can translate to fewer disruptions and lower maintenance costs.
  • Future-Proofing: As governments worldwide set more stringent energy efficiency standards, retrofitting now can ensure your building remains compliant and avoids potential future penalties or mandatory upgrades.
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By transitioning to electric heating and hot water systems, we’re not only reducing our carbon footprint but also investing in a future of operational efficiency and economic resilience. One of the most effective ways to achieve this transition is by embracing the power of heat pumps.

Switching to Heat Pumps

In the quest for sustainable heating solutions, heat pumps have emerged as a pivotal component. These versatile systems, capable of both heating and cooling, offer energy efficiency that’s hard to match. As the shift away from traditional gas systems gains momentum, heat pumps stand out for their ability to harness heat from the environment, amplifying it for our use.

The broader goal is clear: decarbonise our existing heating and hot water systems. Transitioning to electric solutions, especially heat pumps, is a significant stride towards this objective. When paired with renewable energy sources, the result is a dramatic reduction in emissions and a boost in system efficiency. But this isn’t just an environmental endeavour; it’s a strategy aimed at long-term cost savings and operational excellence.

At Automatic Heating, our expertise lies in navigating the challenges of this electrification journey. Through innovative engineering, creative strategies, and foresight, we’re paving the way for a greener, more efficient future.

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Retrofit Planning Essentials

When transitioning to modern, energy-efficient heating and hot water systems, it’s essential to approach retrofitting with a comprehensive understanding of the building’s unique needs and challenges. The following factors play a pivotal role in ensuring a successful retrofit, optimising both efficiency and cost-effectiveness:

  • System Sizing: Boilers and heat pumps do not offer a straightforward one-to-one replacement in terms of kilowatt output. Equally, without instrumentation measuring the current system energy consumption and water load, determining the building’s requirements can be a mystery. It’s possible the current gas system is oversized and not efficient, so matching like with like is inefficient and ineffective, and considerably more expensive. Some boilers are installed for redundancy and not a true reflection of the kW requirements of the system. With new, high temperature heat pumps it is possible to maintain the heating temp required with considerably less energy input.
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  • Electrical Capacity: Older buildings often grapple with outdated electrical infrastructure. Before retrofitting, a thorough assessment of the building’s electrical capacity is essential to ensure the new system can be supported without overloading the existing circuits.
  • Space: Heat pumps typically require more space than traditional gas water heaters. Creative solutions are essential, such as utilising car parks with forced ventilation that have higher ambient temperatures than outside, or building rooftops. An illustrative example is the 600 Bourke Street project, which deploys heat pumps in a car park to produce domestic hot water for end-of-trip facilities.
  • Equipment Placement and Access: The placement of retrofit equipment is a crucial consideration. The choice of location is influenced by several factors, including the noise, weight, and size of the equipment. Adjustments might be necessary depending on the site, and proper ventilation is paramount for heat pumps to operate efficiently. Beyond the physical placement, the logistics of retrofitting can have significant implications on project costs and timelines. Considerations include potential costs for crane lifts or the time and expense associated with installing multiple smaller units. A case in point is the Park Royal project, where budget and power limitations necessitated a staged retrofit approach to achieve the desired outcome.
  • Location (Geographic Considerations): The geographic location of a building can directly influence the retrofit strategy, especially when considering the load. For instance, the load directly affects the capital expenditure (capex). Starting by electrifying just 20% of the current system can provide insights into how often boilers are needed. Regional temperature variations play a role here; for example, Melbourne experiences colder temperatures during winter compared to Sydney, which can influence heating requirements and system efficiency.
Revere CO2 heat pump and Thermex tanks
  • Hot Water Temperatures in Retrofitting: When retrofitting older buildings, one of the primary challenges is accommodating the existing hot water temperature requirements. For heating hot water, many existing systems operate with flow and return temperatures of 80°C/60°C. Retrofitting with heat pumps designed to cater to these requirements, can avoid the need for extensive system replacements. For domestic hot water, CO2 heat pumps are capable of achieving temperatures up to 90°C. When combined with thermal storage tanks, these heat pumps can effectively meet hot water demands which previously required a gas-fired boiler with a higher kilowatt output. In the context of retrofitting, selecting the right heat pump technology is crucial to ensure seamless integration with existing systems and to meet the building’s hot water needs.
  • Staged Electrification: A phased approach to electrification can be both budget-conscious and efficient. By electrifying in stages, budget constraints are addressed, and real building data can be gathered to inform subsequent phases. This approach allows for adjustments based on actual performance, ensuring optimal system efficiency throughout the retrofit process.
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Strategies for Beginning the Electrification Journey

Embarking on the electrification journey can seem daunting, especially when faced with the prospect of a complete overhaul. However, the path to full electrification doesn’t have to be an all-or-nothing endeavour. By adopting strategic steps and understanding the nuances of the process, businesses and building managers can navigate the transition smoothly and efficiently.and for active space heating and contribute to a flatter grid demand profile. By lessening the peak demand and temperature lift, you are not only reducing the space requirements and size of equipment to be used but also helping the heating system perform more effectively and efficiently.

  • Collaborative Planning: The first step is to bring everyone on board. Engage with all stakeholders, from building managers to occupants. Their insights and feedback are invaluable. By understanding their needs and concerns, you can shape an electrification strategy that aligns with both operational demands and user comfort.

Practical demonstrations and presentations at our Training Pod are a great way to learn about heat pump technology.

  • Continuous Monitoring: Once you’ve initiated the electrification process, it’s crucial to keep a close eye on system performance. Implement monitoring tools to track energy consumption, system efficiency, and other relevant metrics. This continuous oversight allows for timely adjustments, ensuring that the system is progressing towards full electrification while maintaining peak performance.
  • Understanding the Challenges: Every building and system will have its unique challenges. Whether it’s hot water temperatures, space constraints, or budgetary limitations, being aware of these challenges from the outset allows for better planning and resource allocation.

As we delve deeper into the electrification process, one strategy stands out for its feasibility and efficiency: Staged Electrification. This approach, which we’ll explore in the next section, offers a balanced path to electrification, allowing businesses to transition in phases, making the journey both manageable and sustainable.

Staged Electrification

We know that removing all gas is the preferred option, but in practice, it’s not always straightforward due to various constraints. Meeting government-set targets for complete gas removal can be easier said than done. Instead, it may be appropriate to ditch the all-or-nothing mentality and consider a staged approach. For instance, electrifying just 20% of the current system can sometimes handle 80% of the load. By electrifying in stages, you can address budget constraints and gather real building data over time. This long-term strategy ensures a more accurate and energy-efficient selection of appliances for space heating and domestic hot water.

Why Electrify in Stages?

  • Budget Constraints: To comply with budget allowances, part electrification enables a smaller initial outlay. Existing gas boilers can be retained for periods of increased demand.
  • Accurate Measurement: Without proper instrumentation, the energy requirements of a system, including heating and hot water load, may be unclear. Staged electrification provides the time needed to gather this data.
Revere O2 heat pump prefab package
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  • Efficiency in Stages: Electrifying in stages allows for the integration of systems with higher COPs initially, leading to immediate reductions in power consumption. As the transition progresses, the cumulative efficiency gains can be substantial.
  • Staged Reduction in Emissions: Installing electric systems in the early stages of a retrofit inherently contributes to reduced emissions. As more stages are completed, the cumulative impact on emissions reduction increases. Specifically, integrating CO2 heat pumps, which have a superior Global Warming Potential (GWP), set the foundation for a more environmentally friendly transition. This approach ensures that even partial electrification has meaningful benefits for the environment.
  • Power Continuity and Backup Security: Electrifying in stages ensures that there’s no compromise on the kilowatt output required for the building’s needs. By retaining and utilising the existing plant equipment as a backup, you ensure consistent power output. This approach also provides a safety net, allowing the old equipment to serve until its end of life, ensuring there’s no disruption in service or power output during the transition.
  • Time Considerations: Upgrading a building’s power supply to support full electrification of building systems takes time. Partial electrification can bridge the gap, allowing for the necessary lead time to upgrade the electrical supply.
  • Resource-Efficient Transition: Electrifying in stages promotes a sustainable and resource-conscious approach. By utilising existing appliances until their end of life, we ensure that resources are not wasted prematurely. This not only maximises the value derived from the initial investments but also aligns with eco-friendly principles. The full changeover to an electric system then becomes a seamless transition, achieved without unnecessary wastage or redundancy.
  • Case Study: The Yarra’s Edge apartment building serves as a practical example. With 4 x Revere CHE heat pumps and 2 x Meridian condensing water heaters, they’ve retained gas boilers as backup, which are rarely used.
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Maximising Retrofits for a Sustainable Future

The essence of retrofitting lies not just in upgrading systems, but in making the most of what’s already in place. By harnessing existing plant equipment and infrastructure, we can achieve a seamless transition to electrification while promoting sustainability and resource conservation.

  • Optimising Existing Equipment: Before diving into new installations, it’s essential to assess and optimise the current equipment. This approach not only reduces costs but also minimises waste. By reusing and repurposing, we adhere to a sustainable ethos that values resource maximisation.
  • Planning for Future Upgrades: A successful retrofit is one that not only addresses immediate needs but also lays the groundwork for future enhancements. By designing systems with future upgrades in mind, we ensure longevity and adaptability. The Willoughby Leisure Centre project exemplifies this approach. While the existing equipment was optimised for the current retrofit, provisions were made to accommodate further electrification and upgrades, ensuring a sustainable solution for years to come.
  • Staged Electrification: Sometimes, a phased approach is the most practical and efficient way forward. Instead of a complete system overhaul, consider electrifying in stages. This strategy respects budget constraints, allows for real-time data collection, and ensures a more accurate and energy-efficient selection of appliances in the long run.

By maximising the potential of existing systems and planning with foresight, we can achieve retrofitting solutions that are both efficient and sustainable, paving the way for a greener future.


System engineering for electrification retrofits

The engineering behind retrofitting is not just about replacing old systems with new ones; it’s about selecting the right technologies that align with the building’s requirements and future-proofing the system for advancements in heating solutions. Here’s a closer look at some of the state-of-the-art products and considerations:

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Revere CO₂ Air to Water Heat Pump

This heat pump stands out for its efficiency and versatility. With the ability to produce water temperatures up to 90°C, it’s an ideal choice for retrofit projects that require higher water temperatures. The use of natural refrigerant R744 ensures minimal environmental impact, making it a sustainable choice.

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Revere AHG130HT Heat Pump

Designed specifically for retrofit projects, the AHG130HT can operate at 80°C supply and 60°C return temperatures. This makes it a game-changer for buildings with systems designed for 80/60 operation, allowing for a seamless transition without the need for extensive modifications. Its cutting-edge inverter technology ensures optimal performance and energy efficiency.


Revere CHE Series Air to Water Heat Pump

This series is known for its high efficiency and the ability to produce water temperatures up to 75°C. Its use of natural refrigerant R290 ensures a low global warming potential, making it an environmentally friendly choice. The CHE series is versatile, suitable for space heating, pool heating, and domestic hot water production.

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In addition to selecting the right heat pump, system engineering also involves:

  • Thermal Storage Tanks: These tanks play a crucial role in ensuring consistent hot water supply, especially during peak demand periods.
  • Ancillary Equipment: Expansion tanks and buffer tanks are essential components that ensure the system operates smoothly and efficiently.
  • Prefabrication and Skid Frame Assembly: By prefabricating heating and hot water systems and assembling them on skid frames, installation becomes quicker and more efficient, saving valuable time on-site.

At Automatic Heating, we understand the intricacies of system engineering for electrification retrofits. Our expertise lies in selecting the right products, optimising system design, and ensuring a seamless transition from traditional systems to modern, efficient, and sustainable heating solutions.

Want to Learn More? Dive deeper into the world of heat pumps and their applications in retrofit buildings. Visit our Training Pod for informative sessions and hands-on experiences.

Case Studies

True retrofits are where theory meets practice. Case studies, such as the Yarra’s Edge apartment building with 4 x Revere CHE heat pumps and 2 x Meridian condensing water heaters, showcase the tangible benefits of retrofitting. From removing gas systems to installing state-of-the-art heat pump systems, these real-world examples offer insights and inspiration.


The journey towards retrofitting and electrification is both a challenge and an opportunity. As we transition to a more sustainable future, the choices we make today will shape the energy landscape of tomorrow. Retrofitting is not just about replacing old systems; it’s about embracing innovation, optimising efficiency, and making a positive impact on the environment.

At Automatic Heating, we’re more than just a service provider; we’re industry leaders, innovators, and sustainability advocates. Our commitment to offering tailored solutions, expert insights, and unwavering support ensures that our clients are well-equipped to navigate the complexities of retrofitting.

Ready to Begin Your Retrofitting Journey? Whether you’re looking to explore the latest in heat pump technology, seeking consultation on retrofit strategies, or simply want to learn more about our range of products and services, we’re here to help. Reach out to Automatic Heating today and let’s shape a sustainable future together.

Heating system design

Retrofit Heating Solutions FAQ

What's the solution to achieving desired hot water temperatures in retrofitting?

The ideal solution is to use high-temperature heat pumps combined with thermal storage. For instance, CO2 heat pumps can achieve temperatures up to 90°C, making them highly effective for this purpose. Additionally, adding instrumentation can further optimise the system’s performance.

How can space and ventilation challenges be addressed in retrofitting?

Creativity is key! Consider unconventional spaces like car parks or rooftops for equipment placement. A prime example is the 600 Bourke Street project, where heat pumps were installed in a carpark, effectively addressing space constraints while ensuring proper ventilation.

How can budgetary constraints (CAPEX) be managed in retrofit projects?

One effective approach is to adopt a hybrid system. Start by electrifying just 20% of the current system, which can sometimes handle up to 80% of the load. Retain gas systems for peak loads, which might only be required 20% of the time. This staged electrification not only increases efficiency but also significantly reduces emissions.

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