Scentree – An Interactive Installation for Conversation about Air Quality

Team: Rachel Kim, Shawn Koid, David Lin, Matt Prindle

Research and Design Method: Research through Design, Physical Prototyping

Duration: 2 months


Scentree is an interactive installation developed for Climate Change Pathways – Research Through Design class. In this class, we were exploring ways to spark discussions around climate change using Research through Design (RtD) methods.

In the final exhibition, people gathered under the Scentree

My team started our project with a shared interest in the Air Quality Index or known as AQI.

Pittsburgh is known for having poor air quality. One day, we checked the AQI on the weather broadcasting APP. It indicated “AQI 61, moderate“. Indeed, we’re not quite sure what AQI 61 is… but one team member brought up that “sometimes it smells like rotten eggs“. This leads to our initial inquiry: ​

Is it possible to tune our sense of smell in order to do away with AQI’s meaningless quantitative measure and, instead, practice a sensuous way of knowing—an embodied way of accessing data about the quality of the air we breathe?

During the 2-month design and research process, we went through three major phases: idea explorations, artifact making and testing, and final installation creation.

Idea Explorations

The human nose becomes numb to scent in as little as two breaths. This phenomenon, nose blindness, is helpful in identifying sharp changes in the smell that might signify environmental danger, but helpless in our recruitment of the nose as a persistent environmental sensor.

In this phase, we tried to understand people’s perception of smells and air quality. We assumed people working with natural scents would be sensitive to air and smells. We visited the local winery, honey farmers, farmers market, and a DIY natural perfume store to collected people’s stories about senses, tastes, smells, and air. We met with cider makers who told us the change in the humidity of the air will influence the taste of cider made from the same type of apples; the honey farmers who can easily distinguish the kinds of flowers the bees had visited based on the tastes and the texture of honey…

The visits gave us hope that people could actually train their senses to be aware of the change in the natural environment, including the change in the air.

Artifact Making and Testing

Borrowing from the practices of sommeliers and perfumers, we recreated the scents associated with the five major air pollutants for which AQI accounts: ground-level ozone, particle pollution (PM10 and PM2.5), carbon monoxide, sulfur dioxide, and nitrogen dioxide. We use ingredients such as garlic, brown sugar, ink, pine leaf, etc. to create scents that are close to the smell of these different particles.

Final InstallationThe Scentree

We finally decided to present these scents in a dedicated location which will invite people to interact, smell, and spark their discussions about air quality.

The experience included three steps: I. Interaction with the Scentree II. Reflections III. Post reflections

I. Interaction with Scentree

The experience of our research tool begins with the diffusion of these scents disguised amongst the leaves on the branch of a tree. Circulating air (or a fan) carries the noticeable scents toward idle noses. A closer inspection of the tree reveals their origin along with information about what kind of air is associated with this scent. Participants can take the perfume card with them for further inspection or as a sample “reference smell”.

II. Reflections

Unlike the quick whiff of some unidentifiable odor in everyday life, here the smell, its associated AQI, and its place or mechanism of origin persist. Nose blindness is no match for the high availability and portability of AQI’s “reference smells.” After engaging with the diffuser, participants are asked to optionally reflect on their thoughts and feelings. All materials can be collected and taken home.

III. Post-reflections

After identifying the scent in the Scentree, participants also can match it to a postcard which contains more information about the source of the smell. Participants can take back the postcards. The postcards intended to continue the engagements with the participants to enhance their experience with the Scentree.