With Hong Kong registering one of its worst days of air pollution recently, the issue of air quality and how to clean up the city is being discussed with renewed vigour. As government bodies and the public work to figure out solutions, private sector figures are also playing a huge part in helping to solve what is justifiably considered a crisis in Hong Kong.

Among those making an impact is Dr Conn Yuen, director and founder of CO2nnsulting (pronounced "consulting"), a carbon-neutral-sustainability boutique consultancy, which advises on unique environmental, climate and energy projects.

Yuen's personal vision, as well as that of her company, is to revolutionise current practices in the architectural and construction fields to promote environmental considerations, reduce urban heat islands (metropolitan areas that are significantly warmer than their surrounding rural areas) and improve air ventilation through architecture and design. She advises government bodies and developers on sustainable master planning, renewable energy projects, air-ventilation assessments, corporate sustainability and climate-change services, and carbon audit and management.

"I was always interested in fluids and how things move," Yuen says. "When I came to Hong Kong, I was interested to see how buildings interacted to disperse the pollution and exhaust fumes through air movement. I started looking at the planning of Hong Kong and that's when I started helping the planning department to come up with outline zoning plans to improve the ventilation."

Some of the planning projects that Yuen has been involved in include air ventilation assessments in Shau Kei Wan, Kowloon Bay and Causeway Bay. She has also been involved in town planning and architectural projects such as the Tung Chung 37 Residential Project and the Marriot Courtyard Hotel in Sha Tin.

While Yuen's business is making positive contributions to the environment, she is humble when asked if she feels she is making a difference.

"I don't think about it like that," she says. "I do it because it's interesting, and I feel fortunate I can find some use for my interests and apply them to something tangible. That excites me a lot. We're all just trying to do our bit."

Yuen was educated in Britain and boasts a successful career as a thermofluids specialist working for industry heavyweights such as Rolls Royce, Alstom Power gas turbines and Dyson cyclonic vacuum cleaners.

Perhaps it was her time at Dyson that offered a hint of her life's calling. "When I was working at Dyson, it was a very small company at the time and no one had heard of them," she says. "I worked in the R&D department, which was only me really, and I spent all day testing the [vacuum] cleaner and measuring its performance. The design involved a cyclone and I realised that what happens in household things can operate on a bigger scale."

She explains that this insight helped to build her knowledge about flow and movement, which defined her later career. "I realised that if flow can work in a vacuum cleaner and in buildings, then buildings are a lot more tangible and you can really make a change. The time to make a change is also so much shorter, so I moved into the building industry," she says.

Yuen's scientific obsession with the study of flow eventually saw her going back to university to study thermofluids at Imperial College London. "My research then was to catalogue images of dots and flows in helicopter engines, then analyse how big the recirculation zone was," she says. "I really loved looking at science. If it doesn't work, you try and figure it out. You get cuts and bruises but eventually it works. It's just really fun. I started thinking, 'Wow, I really like doing this.'"

Her passion led to two research offers: one to work with cars, the other with turbines. Naturally, she chose turbines. While her research and academic success would be the envy of many, finding a job after finishing her doctorate proved no easy task.

"Some of the obstacles I faced included HR trying to match keywords in my résumé to job descriptions, rather than looking at the whole," she says. "I wrote hundreds of letters and spent so much on stamps. It was expensive back then."

Eventually Yuen got her break when a fellow aeronautical engineer saw her résumé and knew what she could do. Since then, Yuen has been involved in international architectural projects including the Vattanac Capital Tower in Cambodia, the Satra Tax Plaza in Vietnam and the Brooklyn Bridge Park in New York.

Yuen says her favourite projects so far have been the ones that have had more of an environmental impact than a visual one. Her long-term vision, however, is not just about air quality.

"I want to create a low-carbon city. I'd like to lower our emissions, energy and water use, and I'm not talking about building carbon-negative cities. You have to do it in steps," she says. "It starts with the little things, for example, like not dropping rubbish on beaches. I've seen progress in Hong Kong since 2005 when I first came. At least people now have an awareness."