English

Urbanization has led to systemic environmental factors that degrade air quality and microbial diversity, negatively impacting human health and wellbeing. Conventional building Heating, Ventilation and Air Conditioning (HVAC) units that filter airborne pollutants and support Indoor Air Quality (IAQ), are often energy intensive, decrease indoor microbial diversity, and are still unable to address specific pollutants or seasonal psychrometric profiles.

The present study investigates acoustic comfort in naturally ventilated residential buildings through an indoor soundscape approach. Preliminary results from a laboratory listening test are presented, where, in a mock-up living room with a window sight, participants have been exposed to 20 acoustic scenarios, obtained as a combination of 4 indoor sound sources and 5 outdoor urban environments filtered through a window ajar. Participants were asked to rate each exposure condition.

The steady-state concentration of occupant generated carbon dioxide (CO2) is used in some applications as an indicator of compliance with a required ventilation rate. These applications assume that the CO2 is at a uniform concentration in the space being considered, and that the outdoor concentration, ventilation rate, and CO2 emission rate are all constant. Emission rates are often derived using an equation in the ASHRAE Fundamentals Handbook, which is poorly referenced and not based on the most recent understanding of the principles of human metabolism.

This study aims at obtaining feedback from occupants of low-energy retrofitted houses concerning the indoor environmental quality (IEQ) and the building systems in their homes. A questionnaire study was carried out in a social housing complex consisting of 2007 single-family houses, of which 1305 were retrofitted between 2014 and 2019. The different retrofitted houses were equipped with two types of heating systems, as well as balanced mechanical ventilation with two inlet locations.

The sudden global outbreak of coronavirus diseases 2019 (COVID-19) has infected over seventy million people and resulted in over one million deaths by the end of 2020, posing a significant threat to human health. As potential carries of the novel coronavirus, exhaled airflow of infected individuals via coughs, are significant in virus transmission. This study measures human coughs' airflow velocity in a chamber filled with stage fog employing a particle image velocimetry (PIV) system.

A longitudinal study was conducted to establish metrics on perception, concentration and characterization of indoor air quality (IAQ) at a university library building. A questionnaire was applied to library staff in 2016 and 2017 to measure perceived indoor air quality (PIAQ) and perceived respiratory health impacts (PRHI). Measurements of PM2.5-10 and PM2.5 concentration levels were made in 2017 and 2019, respectively.

A major challenge in the built environment is the integration of energy and indoor environmental quality in the optimization of existing buildings. The UK’s target of net-zero energy buildings by 2050 brings in the need to optimize existing buildings for energy efficiency and to provide better indoor environmental quality (IEQ). The complications are the monitoring of the indoor environment for better indoor air quality (IAQ) and thermal comfort without compromising the energy efficiency of the building.

Respiratory infections are transmitted by droplets and droplet nuclei generated by human coughing, sneezing, and talking. Droplets and droplet nuclei come out of the mouth simultaneously with airflow, and their dispersion characteristics are important to understand the transmission route of infection. It is crucial to understand the dispersion characteristics of droplets and droplet nuclei dispersion and infection routes through numerical analysis.

The materials that compose the built environment have a key role in the resulting energy demand since their thermal properties affect the heat transfer processes. The use of cool materials aims at increasing the albedo of the urban surfaces and decreasing the heat absorbed by them. Cool materials can decrease roof temperatures, reduce energy needs for cooling and improve indoor comfort for spaces that are not air conditioned.

Ventilation in dwellings is likely to be impacted by configurations of windows and internal doors, but there is little empirical research investigating this in occupied homes. Closure of internal doors will affect noise, light, heat flow and how air moves into and through a building, as well as the volume of air in which pollutants are diluted.