Healthcare buildings are critical for the health and wellbeing of our communities, yet they are also some of the highest energy consumers in the built environment. How can we enable our healthcare facilities to operate in a carbon positive future?
To guide our communities into a renewable energy, emission-free and climate resilient future, WSP’s Associate Director of Mechanical Engineering, Jonathan Ramajoo and Sean Holmes, WSP’s Associate of Sustainability and Technical Partner with the Green Building Council of Australia (GBCA) discuss how we can transition healthcare buildings into being 100 per cent electrified.
Transitioning to a carbon positive world
To slow the effects of climate change impacts, transitioning to a carbon positive world is needed. As a major energy consumer, it’s integral for the property sector to develop a pathway to transition our energy-intensive buildings into a renewable energy and emission free future.
Since the 2015 COP21 Paris Agreement, industry and all Australian states and territories have set net zero emission targets and implemented policies to reduce greenhouse gas emissions by 2050 across the economy.
In a recent analysis by ClimateWorks, it was found that 37 per cent of local governments assessed (representing 21 per cent of the Australian population), have a target to reach net zero for operational and community emissions, either by or before 2050.
Similarly, the GBCA will soon release its next generation of Green Star rating tools. With a focus on facilitating a net positive future for the built environment, one of the new requirements to achieve a 6 Star rating will be for a building to become fully electrified and powered by 100 per cent renewables.
Jonathan says, “As we start to see more real action being taken, both by government and industry, it’s time that we start rethinking our projects and ensuring these developments will be viable in a carbon positive world.
“Due to the critical nature of healthcare facilities, it’s integral that we develop a pathway to carbon positive. This will ensure these buildings can operate efficiently in a carbon positive future while still providing the reliable infrastructure that hospitals need.”
Sean says, “Each building added to our stock which isn’t at least carbon neutral, is adding to the carbon footprint and sending society in the opposite direction of where it should be headed.
“We are now at the point where it’s no longer sufficient to reduce the amount of operational carbon or commit to an emission target of net zero by 2050. We should be using carbon positive as the benchmark now, rather than code compliance.
“If an organisation in our industry is truly looking to demonstrate leadership, it will need to deliver carbon positive outcomes much sooner than 2050, by targeting solutions now and in the very short-term future.”
Ensuring the future resilience of hospitals
Currently, there are approximately 700 public hospitals and over 600 private hospitals in Australia. Whilst capital expenditure remains strong for new developments in health infrastructure, the future resilience of hospitals across the extended lifecycle of these assets is crucial.
Sean Holmes explains, “With healthcare buildings being one of the highest resource consumers in the built environment, all new developments should be building in a carbon positive strategy at business case phase, or risk becoming stranded assets in the medium-term future.”
According to the GBCA, healthcare facilities use at least twice as much energy and around six times as much water per square metre than commercial office buildings. Consequently, these critical pieces of infrastructure will be one of the most important buildings to achieve carbon neutrality in operation.
“These facilities operate 24/7, powering specialist medical equipment and significant heating, ventilation and air conditioning demands,” adds Sean. “Not to mention, most of the existing health infrastructure is ageing and wasn’t designed for energy efficiency or future electrification.”
Rethinking the HVAC system
The clearest solution for buildings to operate carbon neutrally is requiring deep energy efficiency across the technical and spatial elements of the building design. This involves transitioning from gas fuel to electrification which can be powered 100 per cent by a mix of on-site and off-site renewables.
Jonathan says, “As markets across the built environment begin to develop a roadmap to achieve carbon neutrality for buildings, the real challenge however is deploying new and innovative technologies to healthcare facilities. Where people’s lives are literally at stake, the engineering solutions we develop must be robust and reliable to ensure these buildings can operate safely.
“We know the building services infrastructure is one of the most integral services in a hospital, and traditionally the Mechanical Heating system, Domestic Hot Water (DHW), space heating, sterilisation processes and cooking is all processed typically with natural gas fired plant.”
Sean expands, “The challenge now for designers of healthcare facilities is to remove gas from the buildings and identify sustainable solutions for addressing the 100 per cent electrification target, where the mechanical HVAC plant and hot water generators can rely on electricity and onsite renewables. Electric systems in a hospital context operate intrinsically differently – it’s not as simple as swapping one for the other.”
Jonathan adds, “By applying a future ready lens, we’ve developed a particular solution that focuses on the removal of gas from powering these heating systems, still has the ability to meet peak demand and achieve high efficiency. This solution is being implement on a new large-scale Acute Hospital development that WSP are currently designing.”
Rethinking the plant configuration
Different climates across Australia present unique challenges for transitioning from gas fuels to electricity. Southern states, where there is a higher demand on heating in winter, pose a significantly greater challenge. Without smart and efficient use of thermal systems and building designs, the peak electricity demands can occur overnight in below freezing conditions and where heating demands are highest.
Jonathan explains some smart solutions designed by WSP, “We’ve used reliable systems and technologies, but applied these in a whole of life approach to develop optimisation strategies for an optimum plant configuration. This incorporates a combination of thermal storage and spill dissipation coils located in relief and exhaust air steams.”
The primary aim of this plant configuration is to maximise the use of 4-pipe water cooled chillers, which can provide simultaneous heating and cooling. This increases the efficiency of thermal heating during a peak winter season, while maintaining the robust operation required by an acute-services building.
“By reducing the spatial requirements of the mechanical central plant, then 4-pipe chillers can be used to provide the cooling-only required from the high efficiencies during summer, which may reduce the size of alternate air-cooled heat pumps required to provide the peak heating demands in winter,” adds Jonathan.
“Furthermore, we have factored in the cost of electricity, maintenance and replacement cycles in our solution, taking a whole of life optimised cost approach to achieving the best possible net positive carbon outcome.”
Together, these strategies provided an efficient pathway to manage the critical risks of fuel switching from gas to electricity, both within the building operations and with managing the burden placed on the already stretched electricity grid.
Sean says, “Implementing an all-electric strategy will be a key enabler to achieving an all renewables outcome, through onsite and offsite renewables. By delivering these strategies together, we can achieve a net positive carbon outcome.”
Key steps for a net positive carbon outcome
Jonathan and Sean believe the following hierarchy of steps are key to achieving impactful carbon positive outcomes:
- Super-efficient building fabric and form: focussing on air tightness, real life thermal performance of constructions, passive considerations for windows and shading
- Natural systems: Natural ventilation and daylighting, limited servicing of areas to only those that are necessary
- Super-efficient, all electric building services: where services are needed, selecting the most efficient options possible, along with innovative energy recovery systems, delivering the best whole of life outcomes
- Renewables strategy: delivering maximum on-site renewable energy possible, supplemented by offsite renewables.
“The imperative for the health sector is clear,” says Jonathan. “Given its mission to protect and promote health and wellbeing, the sector also has a responsibility to minimise its carbon footprint and achieve carbon neutrality before 2050. This represents a great opportunity to become a leader in decarbonisation.”
