Robin Mellon, the chief operating officer at the Green Building Council of Australia, explains the psychological factors that impact indoor air quality.
We can design a world-leading sustainable building and fill it with clever cutting-edge technology, but if the building’s occupants prefer to crank up the air-conditioning rather than pulling on a jumper, it won’t be a sustainable building.
True sustainability is found at the intersection between good design, good management and good behaviour. But good behaviour can sometimes be the most elusive or the hardest to maintain.
According to Professor Richard de Dear, head of the Architectural Science Discipline at the University of Sydney’s Faculty of Architecture, Design and Planning, we need to get better at designing "mixed-mode buildings".
These are buildings that are naturally ventilated, but incorporate air-conditioning technology to be used sparingly whenever the external weather is uncomfortable.
According to de Dear, there are six parameters in the "comfort equation" that have a direct physical impact on thermal comfort: air temperature; radiant temperature; humidity; air speed; clothing insulation, and metabolic rate.
All six influence our body’s heat-balance.
But beyond the physics of heat balance is a slew of more subtle but very real psychological effects.
“We know that allowing occupants to exercise as many ‘adaptive opportunities’ as possible – such as clothing, operable windows and shade – has the effect of widening comfort tolerances significantly, and that has the effect of reduced reliance on mechanical cooling,” de Dear explains.
Another psychological effect is the question of “who-is-paying-the-energy-bill?”, which de Dear says goes some way towards explaining the profoundly different temperature tolerances we observe between the home and the workplace.
“We’ve even established pretty convincingly that awareness of environmental issues – ‘tree huggers’ versus ‘climate denial’ types – has a measurable effect on comfort. People with heightened awareness of human-induced climate change issues were demonstrated to be significantly more tolerant of temperature fluctuations in the workplace than their climate-sceptic counterparts.”
These psychological factors have led to what de Dear calls the "wicked problem of designing for comfort in a rapidly changing world".
“It’s a ‘wicked’ problem not only for the psychological aspects, but because the definition of comfort seems to be changing through time,” he says.
“When I was a kid, there was no such thing as air conditioning in school classrooms. Indeed, the notion of sealing up the environment where kids spent their days would’ve seemed ridiculous – healthy, growing kids needed lots of fresh air back then. Nowadays, the kids are often driven to work in air-conditioned cars, spend all day in air-conditioned classrooms, then return home to sit in front of a computer in an air-conditioned home, and I fully expect this will lead to intergenerational shifts in the temperature thresholds of comfort.”
Interesting times ahead, that’s for sure. How comfortable are you with your working environment, your productivity levels and your energy bills?
Richard de Dear was one of the presenters at the GBCA’s ‘Inside IEQ’ event series, which examined IEQ and the important part it plays in sustainability.
This article is part of a special Indoor Air Quality feature to be published in the August edition of Climate Control News Magazine.
- Robin Mellon will be speaking at the CCN Live 2014 conference on August 13, 2014. For tickets email clare@twodeforce.com.au