A.G. Coombs is working to develop scalable “plug-and-play” replicable solutions for retrofits and electrification, with embedded carbon smarts, that manage energy usage, embrace renewables and improve HVAC&R system performance.
When the topic of embodied carbon is raised in built environment circles, the focus is often on the structural materials — for example, the pros and cons of timber versus green concrete. The embodied carbon of building services rarely rates a mention, even though the kit of parts that supplies heating, ventilation, airconditioning and refrigeration (HVAC&R), light and power has a complex, high-emissions supply chain.
According to Bryon Price, strategic development director at A.G. Coombs, as the industry turns an eye to existing buildings and how to improve their performance, it is vital to understand embodied carbon in mechanical systems.
That means looking at the whole interconnected suite of technical systems – pipes, wires, ducts, pumps, chillers, refrigerant gases, boilers, fans, switchboards, controls…it’s a microcosm of the industrial ecosystem, and every item has a unique embodied carbon footprint.
The complexity has long been a challenge – for example, calculating the impact of a copper pipe made in Australia compared to a chiller made overseas, or refrigerant gases with a wildly complex offshore manufacturing and packaging supply chain.
“There are emerging methods of calculation and once you’ve got a measure or metric on that footprint, then you can make more meaningful decisions, particularly in refurbishments, about what you keep,” Price explains.
This kind of thinking also strips away the branding around net zero. It makes it obvious that simply replacing everything with the latest and greatest energy-efficient kit, signing up to green power and then offsetting residual emissions is not what genuine net zero
looks like.
Decisions on the retention or replacement of system elements in a retrofit should take into account both operational and embodied carbon impacts. It may be favourable for example to retain a system element that has less than outstanding operational emissions but very significant embodied carbon, long remaining lifespan and a reasonable maintenance burden.
Embodied emissions are also currently the first and best metric for measuring circular economy applied to building services, Price explains.
“Addressing resource circularity and lifecycle environmental impact is essentially a design challenge. Recognising that the occupancy requirements for buildings continue to change over time, designing for flexibility, adaptability and durability in building services is important. And in that an understanding of embodied carbon is significant along with operational realities.”
The challenges of electrification
While gas can be replaced there needs to be sufficient electrical infrastructure and supply capacity around the building and within the building for it to be feasible. There are often also other physical issues that must be addressed including space, ventilation, access and floor loading requirements for electric systems.
Add into that picture the “massive investment” required for changing the grid and generating, distributing and storing zero carbon electricity, and the scenario gets even more complicated.
Every bit of the puzzle involves carbon emissions somewhere from extraction, processing, fabrication, distribution, installation and maintenance.
“When we come to devising ways to replace gas fired systems in buildings one of the important issues to consider is that we are traditionally takers of commodity technologies,” Price says.
“Our industry skill-sets are founded on that. It is important that the technical replacement solutions we develop and apply are affordable and able to be scaled and repeated. Not one off bespoke complex installations that are challenging to design, install and maintain.“
A “plug and play” solution on the way
Price says A.G. Coombs is focused on refining electrification solutions that meet this need for water heating requirements in buildings. A scalable combination of high performance heat pumps, smart water storage, and integrated solar PV has already been retrofitted in a large high-profile Melbourne building.
The project has proven to be a success and has been recognised with an industry Integrated Clean Energy award.
The company is working to take this to the next level, ensuring its solutions are “plug-and-play”; replicable and scalable.
The other side of the equation – which brings us back to embodied carbon and emissions – is recognising that not every building will be a straight swap out of the old and plug in the new.
The carbon roadmap for any building needs to consider the life cycle of existing equipment, and the trade-off between the operational energy that gets saved through replacing it and the embodied emissions impacts of the various parts going in and coming out.
“You can’t achieve net zero in a building unless you get the technical bits right.”
“This involves a more complex approach than previously applied. It requires both life cycle thinking and life cycle behaviour. A whole-of-life approach that connects the building’s supply chain, from designers, manufacturers, and installers through to its owners, operators, maintainers and occupants – and in that it creates a true value chain.”
