My PhD Research

The relationship between ventilation practices and indoor environmental quality in British homes

Degree: Doctor of Philosophy (PhD)
Institution: University College London, Bartlett School of Environment, Energy and Resources
Program: London–Loughborough EPSRC Centre for Doctoral Training in Energy Demand
Duration: 2018–2024
Thesis: The relationship between ventilation practices and indoor environmental quality in British homes

Description

Doctoral research investigating the relationship between ventilation practices and indoor environmental quality (IEQ) in British homes through an empirical mixed-methods approach. Europeans spend most of their time indoors at home, where IEQ plays a critical role in occupants’ comfort, well-being, and physical health. Ventilation modifies indoor temperatures, air quality, and noise, while also affecting heat transfer, energy use, and carbon emissions in homes with space conditioning—positioning ventilation at the intersection of health, energy, and climate.

This research employed comprehensive IEQ monitoring in seven occupied case study dwellings in England to investigate ventilation practices, air exchange rates (AER), and their relationships with IEQ parameters and pollutant dynamics. I was responsible for the complete research lifecycle including study design, ethics, development of novel measurement methodologies, deployment of high spatio-temporal resolution monitoring systems, occupant survey administration, advanced data analysis employing multivariable statistical methods and machine learning techniques, and dissemination through a thesis and peer-reviewed publications.

Key Findings

  • Developed and validated a novel method to determine window positions (open, ajar, closed) using simultaneous indoor/outdoor sound measurements, achieving up to 96% accuracy
  • Revealed substantial variability in ventilation practices and air exchange rates across homes and seasons, highlighting challenges in generalising findings
  • Found windows and doors were closed most of the occupied time, particularly during winter
  • Demonstrated that most homes had air exchange rates below commonly accepted healthy thresholds during occupied periods
  • Established that opening windows generally reduced indoor temperature, humidity, CO₂, CO, and total volatile organic compounds (TVOC), though noise levels and unexpectedly, particulate matter increased
  • Developed novel analysis techniques for quantifying pollutant peak decay times to inform practical public health advice for reducing exposure

Key Contributions

  • Deployed high spatio-temporal resolution IEQ monitoring systems in seven occupied dwellings
  • Deployed virtual private server-based data management and analysis pipelines for large IEQ datasets
  • Developed novel acoustic equipment and method for inferring window positions from sound measurements
  • Conducted comprehensive measurement campaigns capturing temperature, humidity, CO₂, CO, PM₂.₅, PM₁₀, TVOC, formaldehyde, and noise across multiple seasons
  • Administered and analysed occupant surveys to understand ventilation behaviours and motivations
  • Applied advanced statistical methods including multivariable regression and machine learning (scikit-learn, statsmodels, scipy)
  • Quantified relationships between ventilation practices, air exchange rates, and IEQ parameters
  • Developed methods for analysing pollutant decay dynamics and peak exposure reduction strategies
  • Investigated human-building interactions and their impact on indoor environmental conditions
  • Generated evidence base for evaluating health implications of interventions that modify IEQ
  • Published findings

Technical Skills

  • High-resolution environmental monitoring system deployment
  • Python programming for data processing, analysis, and visualisation (pandas, NumPy, matplotlib)
  • Machine learning and statistical modeling (scikit-learn, statsmodels, scipy)
  • Signal processing and acoustic analysis
  • Air exchange rate measurement and analysis (tracer gas methods, CO₂ decay)
  • Multivariable regression and time-series analysis
  • Mixed-methods research design (quantitative and qualitative)
  • Questionnaire design and survey analysis
  • Building physics and indoor environmental quality assessment
  • Data management and quality control
  • Scientific writing and peer-review process