Let’s face it. HVAC is a heavy contributor to the global climate problem.
Globally, CO2 emissions reached 40 billion tonnes (40 Gt) in 2020. With 80 per cent of power generation based on fossil fuels, heating and cooling are responsible for 43 per cent of global electricity use (23 per cent for heating and 20 per cent for cooling). So, the buildings sector is responsible for 33 per cent of global CO2 emissions, thus a key cause of climate change.
And things could get worse, as global demand for AC is expected to increase dramatically due to the increasing economic prosperity of the southern hemisphere, increased urbanization and the warming climate, with some estimating a three-fold increase in demand for AC, others estimate 10-fold increases or more. In either case, the resulting climate impact can make the dire situation we have today much worse.
HVAC is a further contributor to the climate problem as it uses refrigerants that are highly heat-trapping, ozone-depleting greenhouse gases (Hydro-Fluoro-Carbons – HFCs) with a global warming potential many thousands of times greater than CO2.
As developing countries start using more air-conditioning (globally 3.5 billion AC units today but expected to reach 10-plus billion units in 2050), global temperatures will rise even faster and peak hot weather will start earlier and last longer, requiring more air-conditioning, thus more power generation capacity. This will increase the risk of blackouts in the power transmission and distribution network. The northeast U.S. blackout of 2003, California’s rolling blackouts of 2020 and India’s 2012 blackouts were all directly related to higher than expected power consumption due to higher summer temperatures.
So, the warmer it gets, the more AC we use. And the more AC we use, it will get warmer still, further increasing carbon emissions, thus intensifying stress on the climate. A vicious circle that needs to be broken.
This climate stress is neither hypothetical nor theoretical. Under current energy growth scenarios, it is projected that by 2100, approximately 75 per cent of the world’s population will be heat-stressed, exposed to unhealthy — in some cases deadly — levels of temperature and humidity. This is up from 30 per cent today. This heat stress will not only cause significant reductions in agricultural production, it will also instigate weather-induced migration, harm ecological biodiversity, increase the release of hydrated methanes from the permafrost and increase ocean acidification, damaging marine wildlife and coral reefs.
Worth repeating: The buildings sector is alone responsible for approximately 33 per cent of global CO2 emissions. So, it is beyond doubt that the way we design and build has a huge and direct impact on the climate problem.
The short-term viewpoint of many investors/developers, as described earlier, is one of the key factors that shape the building and construction industry of today.
This short-term viewpoint is often reinforced by architects/engineers.
Of course, it is important to state there are many renowned developers, architects and engineers who are pushing the envelope in terms of sustainability and innovation, and should be praised, but they are the exception, not the norm.
In practical terms, their ability to meaningfully impact the global climate is severely limited.
The majority of developers are seeking the most economical design to build, and so pit consultant against consultant in a downward spiral price competition to get to the lowest price and the quickest design.
And even though the specialist consultants’ collective fees are in the single digit percentage of the project cost, their influence is overwhelming and transcends the project planning process, permitting, through to procurement, construction and operation, and so will last for the life of the project.
Paradoxically, paying designers a percentage of the value of a project goes against the developer’s interests, as it encourages some designers to inflate the value of the project (increasing their compensation) by oversizing its components (e.g. HVAC equipment). This can be justified by claiming that this oversizing allows for a safer and more conservative design, which is supposedly good for the owner and also removes potential liability from the designer.
However, this goes directly against the developer’s best interests and also against the architects/engineers’ professional ethos.
But from the architects/engineers’ commercial perspective it is rational. Engineers who strive for an efficient design that reduces their client’s capital and operating costs — let’s say the building’s HVAC system — are penalized twice. First, they need to devote more time and resources to come up with the most efficient design (higher cost for them), and the project’s budget is reduced (lower revenue for them). To top it off, they also do not participate in any of the owner’s operational cost savings their enhanced design has enabled.
This op-ed is the third in a series from Eco-Structures International’s founder and director Ghassan Nimry which focuses on innovative sustainable engineering solutions to today’s climate change problems. He believes that technology can solve many of today’s seemingly intractable problems, but to make it work we need collective work, personal acknowledgement of our role in the problem and our ability to be part of the solution. Send comments to firstname.lastname@example.org.