indoor air quality

In the UK, people spend over 90% of a day indoors. On weekdays, when outdoor air pollution concentrations peak in the morning and in the late afternoon, people are usually either in non-domestic premises or on their way to/from non-domestic premises. Therefore, establishing the distributions of indoor air pollutant concentrations in non-domestic environments is essential to model human exposure to hazardous air pollution, especially for vulnerable populations, such as schoolchildren or patients in hospitals.

This paper reports preliminary analysis from a large field study of 100 university classrooms in Central Texas. Lecture classrooms and auditoriums were sampled for three consecutive weekdays in the 2019 – 2020 academic year. Carbon dioxide (CO2) concentrations, used as a marker for both ventilation and exposure, and temperature were measured in the general room area and when able, the supply airstream. HVAC control data that relates to ventilation was also saved for comparison.

Climate change is driving the construction sector to use of more environmentally friendly and sustainable materials. Hemp concrete has been recently adopted as an innovative solution by the building industry to reduce emissions, as this material stores more CO2 than the emitted during its production. Part of this storage occurs during its service life leading to a reduction of indoor CO2 levels. CO2 has been widely used as a proxy for evaluating indoor air quality (IAQ).

A Personalized Environmental Control System (PECS) aims to condition the immediate surrounding of occupants. This approach is fundamentally different from typical HVAC systems, which aim to create uniform indoor environments, regardless of the occupant preferences. PECS has several advantages including allowing occupants to adjust their immediate surroundings according to their preferences, which could improve their satisfaction with the indoor environment, and may lead to higher productivity.

Personalized Environmental Control Systems (PECS) condition the immediate surroundings of occupants, and they are expected to provide increased comfort, health, and productivity. Studies have reported on their benefits and limitations in addressing individual Indoor Environmental Quality (IEQ) factors, especially in terms of thermal comfort and indoor air quality. The COVID-19 pandemic and risks associated to climate change, such as heat waves, highlight the necessity for PECS that can address multiple IEQ factors.

Personalized Environmental Control Systems (PECS) with the functions of heating, cooling, ventilation, lighting, and acoustics have the advantage of controlling the localized environment at occupant’s workstation by their preference instead of conditioning an entire space. This improves personal comfort, health of the occupants, and energy efficiency of the entire heating, ventilation and air-conditioning (HVAC) system substantially. Some of the major advantages and limitations of PECS are summarized. 

Personalized Environmental Control Systems (PECS) have advantages of controlling the localized environment at occupants’ workstation by their preference instead of conditioning an entire room. A new IEA EBC Annex (Annex 87 - Energy and Indoor Environmental Quality Performance of Personalised Environmental Control Systems) has recently started to establish design criteria and operation guidelines for PECS and to quantify their benefits. This topical session will provide an introduction to the objective/scope, activities, and intended outputs of the annex. 

Ventilation of buildings is a good way of preventing transmission of some virus in aerosolized form as the SARS-CoV-2. In many buildings, prevention strategies as window opening and sealing door have to be considered with a multizone approach. Approach. We modelled a residence equipped with a exhaust-only ventilation system where a family is isolating in a pandemic context, with one infected person. We modelled and analysed the impact of opening the window and sealing the door in the quarantine room on exposures. We tested several window- and door-opening strategies. Results.

Occupant exposure to airborne pathogens in buildings can be reduced by a variety of means, including adequate provision of outdoor air by ventilation. This is particularly important in buildings, such as hospitals, which may house a higher number of infected individuals relative to the wider population. In tropical Africa, however, there is evidence that new hospitals built with air-conditioning to cope with the extreme heat are poorly ventilated compared to existing hospitals that were designed to be naturally ventilated.

This study aims to develop and evaluate an advanced control method for acceptable indoor air quality (e.g., particulate matter and CO2) with low energy consumption in a residential space. A ventilation system, an air purifier, and a kitchen hood system are installed in the testbed to maintain a healthy IAQ. To accomplish the objective, we use a double deep Q-network (DDQN) which is one of the reinforcement learning. This study utilizes a co-simulation platform with EnergyPlus and Python.