CASE STUDY CONTEXT

The Capstone Project undertaken by an undergraduate student and reported in this paper serves as a practical case study demonstrating the value of the supervisor’s research in developing human cognitive governance for value-oriented problem diagnosis and solving. It also demonstrates how this transferable way of thinking can enable undergraduate students to produce scholarship of an academic standard suitable for publication in the Indoor Air Cartoon Journal. By internalising the transferable way of thinking embodied in the supervisor’s research, the student developed appropriate mental models for understanding indoor air quality problems, formulated meaningful research questions, critically interpreted scientific evidence, integrated objective and subjective findings, exercised sound judgement, and translated these into informed engineering design decisions. This cognitive development enabled the student to progress beyond simply constructing a prototype to systematically diagnose a real-world indoor air problem and develop a personalised breathing-zone solution that balanced technical performance, usability, maintainability, and user value. Rather than merely transferring technical knowledge, the supervisor’s research enabled the student to develop cognitive governance as an upstream capability for value-oriented problem diagnosis and solving. Consequently, this Capstone Project illustrates how the supervisor’s research strengthens cognitive competency and its practical execution, providing upstream readiness for applied research, professional practice, and future scholarly contributions.

……………… COMPETENCY BASED EDUCATION CASE STUDY ……………

EXECUTIVE SUMMARY

This Capstone Project investigated the development and evaluation of a personalised microclimate device designed to improve localised thermal comfort and air quality within the occupant’s breathing zone through targeted airflow and low-cost filtration. The study was motivated by the limitations of conventional air-conditioning and mechanical ventilation (ACMV) and heating, ventilation, and air conditioning (HVAC) systems, which regulate overall indoor environmental conditions but do not always address the immediate microenvironment experienced by seated occupants. This limitation is particularly relevant in Singapore’s hot and humid climate, where occupants may continue to experience warmth, stuffiness, or exposure to pollutants despite mechanically conditioned indoor environments. The study therefore examined whether a desk-scale intervention could improve both objective environmental conditions and occupants’ perceived experience within the breathing zone.

A functional prototype was developed by integrating targeted face and neck airflow, low-cost filtration, modular filter cartridges, particulate sensing with a red-green-blue (RGB) air-quality indicator, and simple manual speed control. An exploratory mobile application wireframe was also developed to investigate how a companion digital interface could support user interaction and environmental awareness. The design requirements were informed by a literature review and user survey, which identified the need for targeted airflow, cleaner local air, intuitive operation, and low operational burden.

The methodology combined controlled objective testing with subjective user evaluation. Objective testing was conducted under both occupied and unoccupied conditions using four operating states: No Prototype, Device Speed 1, Device Speed 2, and Device Speed 3. The principal performance indicator was the size-integrated particulate concentration across the 0.300–10.000 μm particle size range, while total volatile organic compounds (TVOCs) were used to evaluate the performance of the activated carbon filter. Carbon dioxide and relative humidity were recorded as supporting environmental parameters. User evaluation was subsequently conducted to assess perceived usefulness, thermal comfort, breathing-zone air acceptability, usability, operational burden, and overall user acceptance.

The results demonstrated that the breathing zone represents a distinct microenvironment, with pollutant concentrations differing from those measured elsewhere within the room. Under both occupied and unoccupied conditions, the prototype reduced particulate concentrations relative to the corresponding baseline condition without the prototype. TVOC concentrations were also reduced, indicating that the activated carbon filter contributed to reducing volatile and odorous pollutants. Although the magnitude of improvement varied according to airflow speed, occupancy, and initial pollutant conditions, all operating speeds generally improved breathing-zone environmental quality compared with the baseline condition. The user evaluation complemented these findings, with participants reporting that the prototype was easy to understand and operate, while the airflow was perceived as comfortable and beneficial. Participants also rated the prototype positively in terms of operational noise, perceived air freshness, and willingness to use the device during work or study. The RGB indicator and companion application wireframe further enhanced users’ understanding of the device and its intended function.

The study also identified several opportunities for further refinement. Experimental variability associated with different occupants and changing background environmental conditions limited direct comparison between individual test runs, while the user evaluation involved a relatively small sample and short free-use sessions. Participants also identified several prototype implementation issues, including inconsistent touch-control responsiveness, weak magnetic filter retention, excessive RGB brightness, short USB cable length, and the overall size of the prototype.

Overall, this study demonstrates the feasibility of improving breathing-zone environmental quality through a low-cost personalised microclimate device that integrates targeted airflow, localised filtration, and user-centred design. The project contributes a functional proof-of-concept prototype, objective evidence supporting breathing-zone intervention, practical design knowledge for future personalised microclimate technologies, and preliminary insight into the potential role of companion digital interfaces in enhancing user interaction and environmental awareness. Collectively, the findings establish a foundation for the continued development of personalised breathing-zone technologies that improve both indoor environmental quality and occupant experience.

Keywords: Personalised Microclimate; Breathing Zone; Indoor Air Quality; Localised Airflow; Low-Cost Filtration

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Cite as: “Teo AKH and Fadeyi MO (2026). Development of a personalised microclimate device for low-cost air purification and cooling for localised comfort. Teaching and Learning Case Studies #09. ISSUU Digital Publishing.”