Last winter, the UK’s ability to navigate an energy crisis was tested. The threat of Russia cutting off gas supplies to Europe and a sustained cold snap raised the prospect of rolling blackouts. The winter months ended up being cooler than expected, however.
Unseasonably mild winters and unpredictable weather patterns are becoming an all-too common occurrence. Hotter summers and milder winters are not only having an environmental and ecological impact, but they can have a negative impact on the broader economy, businesses and productivity. They can also lead to poorer wellbeing and higher mortality rates – research from the Intergovernmental Panel on Climate Change has concluded that climate change adversely affects mental health.
“Increasingly frequent heatwaves can negatively impact equipment, buildings and personnel, leading to reduced efficiencies, operational failures and even complete shutdowns,” say Dr Laura Kent and Dr Tim Fox, the co-authors of the new IMechE report, Adapting Industry to Withstand Rising Temperatures and Future Heatwaves. Kent is a public affairs and policy adviser at the Institution, while Fox is a fellow.
While countries have pledged to reduce their greenhouse gases, they arguably need to be doing more. It’s anticipated that, if global warming continues at its current pace over the next couple of decades, then the 1.5°C target set out by the United Nations Paris agreement won’t be reached.
To help prepare for extreme weather conditions, the built environment and infrastructure need to be adapted. This includes things that are already built and those that are yet to be designed and constructed.
“It’s crucial that industrial organisations plan and implement climate-change adaptation measures in order to build resilience against extreme heat events,” argue Kent and Fox.
Air-conditioning challenge
Up until now, most climate-responsive buildings have been designed with cold winter temperatures in mind: insulation, air tightness and facilitating passive solar heating through facades.
According to data published in the UK government’s 2021 research entitled Cooling in the UK, only 2-3% of households in the country have a portable or fixed cooling system. Of these, less than a third have fixed cooling systems, meaning the bulk have portable cooling systems that are generally designed to cool one room at a time.
When buildings aren’t designed to withstand prolonged periods of hot temperatures, they’re often incapable of passively shedding heat and so become susceptible to overheating. This thermal discomfort impacts those living or working in the buildings.
Fitting all UK households with AC systems, however, wouldn’t make much sense because of what’s known as the urban island heat effect: cities tend to experience hotter temperatures than surrounding natural areas. Relying on AC to combat the urban island heat effect would lead to a surge in energy demand and would be expensive.
Nevertheless, the government has forecast that households will consume between 75% and 85% of the cooling energy consumption by the end of the century. At present, non-domestic buildings are accountable for most of the demand.
Another problem with households blasting out cold air for prolonged periods during hot weather is that the high demand places stress on utility networks, which increases the risk of some of them having to introduce rolling blackouts. This, in turn, can have a huge knock-on effect on businesses and industries, impacting productivity and output and potentially leading to economic losses.
During the heatwave last summer, Google and Oracle had issues with data centres overheating because the cooling infrastructure installed was insufficient and couldn’t offload the additional heat to the outside environment to maintain the required internal temperature. Rooftop-mounted AC units at data centres around the UK were also being sprayed with water to prevent meltdowns. Traditional cooling systems at the largest data centres can consume between hundreds of thousands and a few million litres of water every day. Because of their size, they generally don’t have the room for extra cooling capacity to be designed and built in, which can present challenges when temperatures soar to unpredictable levels.
(Credit: Gary Neill)
Smarter approach to cooling
There clearly needs to be a better and sustainable way to meet future demand for cooling and heating. As the Institution’s report explains, simply transitioning to smarter refrigerants and installing AC systems with higher efficiency isn’t going to work. A new approach should focus on making use of the energy resources needed to begin with. For example, aggregating multiple demands for supply through using distracting cooling networks.
Another smart approach is harnessing available thermal energy resources from the natural environment that can be used sustainably. Free cooling resources include cold water from rivers, lakes, aquifers and even oceans. Thermal energy resources rejected by other processes – waste thermal streams – could also be used to replace primary energy consumption. A case in point is the use of industrial waste cooling from liquefied natural gas (LNG) regasification and cooling water heat recovery use for district heating.
The best way to negate the cost and electricity demand of AC systems is arguably to avoid using active cooling mechanisms altogether and opt for passive solutions, such as making use of natural ventilation, tree shading and nearby natural water sources.
While this sounds OK in principle, it might not work in practice, because the design of existing buildings can present challenges, especially as most urban housing is not near water and doesn’t get any shade from trees.
“There needs to be a strategy of ‘build back better’ to ensure that the refurbishment or repair of aged or damaged buildings and assets is based on net-zero sustainable options and that they are fit for future service in a hotter world,” say Kent and Fox.
“By doing this, organisations can improve their resilience, while making a positive contribution to sustainability efforts.” New and revised standards, engineering design codes and building codes are urgently needed as well, added Kent and Fox.
“Organisations need to encourage and empower their engineers to engage with the relevant standards and code-writing bodies in the drafting, reviewing, updating and approval process,” they advise.
This will give employees the tools to work with their employers to develop strategies for dealing with heat stress that is tailored to the specific needs of the people or businesses occupying buildings.
“This should be an effort between industry and national health-and-safety executives. Senior managers should create an environment that enables teams to develop innovative and timely adaptation solutions,” add the co-authors of the IMechE report.
The next generation
Adapting to extreme heat events through building and engineering design is only going to be successful, though, if the next crop of engineers is equipped with the right knowledge and skills.
As the IMechE report points out, the current technical training and educational systems are designed to operate in a world where the climate is stable and cool temperatures are the norm. But with extreme weather events becoming a common occurrence, the sector needs to ensure that upcoming engineering talent not only has basic climate-change knowledge, but is also aware of the impact a warmer climate is having on the built environment and the need for heat adaptation.
Curriculums need to be linked to the UN’s Paris agreement and sustainable goals. Even more imperative is that these skills are taught at apprenticeship and undergraduate levels. Particular attention should be paid to skills and capacity building for the design, installation, commissioning, inspection, maintenance and disposal of cooling equipment, as well as the enabling, coordinating, implementing, financing, enforcing and evaluating of policies and programmes.
Ultimately, successfully adapting the built environment to extreme heat events is going to require all stakeholders along the value chain to be aligned with the same climate-change goal.
“There needs to be collaboration across borders and disciplines, innovation from all levels of private and public-sector organisations, and a commitment to net-zero outcomes, sustainability and resilience,” conclude Kent and Fox.
READ MORE:
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Using industrial waste heat for district heating networks
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.