carbon dioxide

We sleep more than twenty years during our lives. Sleep is essential for physical and psychological health. Yet, nearly no standards define indoor environmental quality conditions for optimal sleep. In this paper, we present a summary of studies examining the effects of bedroom ventilation on sleep quality. The results suggest that the current ventilation standards for dwellings are inadequate concerning requirements of outdoor air supply rates in bedrooms and need to be revised.

An approach has previously been developed to estimate space-specific carbon dioxide (CO2) levels that can serve as metrics for the adequacy of outdoor ventilation rates. These metrics are based on the CO2 concentration expected in a space given its intended or expected ventilation rate, volume, and occupant information (i.e., the number of occupants, their CO2 generation rates, and duration of occupancy).

With many existing Austrian school buildings to be renovated in the coming years, there are debates between stakeholders, about which ventilation strategy to pursue in existing schools. Therefore, different intervention strategies such as retrofitting ventilation systems, installing CO₂-monitoring signals, or raising awareness among teachers and students should be evaluated. This paper presents the preliminary results of the project “DIGIdat” on air quality measurements in the first quarter of 2023.

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).

In response to the COVID-19 pandemic, many organizations have recommended improved ventilation to reduce the risk of indoor airborne infectious disease transmission. These recommendations include increasing outdoor air rates and filtration efficiencies, as well as verifying that ventilation systems are operating as intended. There have also been many recommendations to monitor indoor CO2 concentrations as indicators of ventilation or infection risk, in some cases with quantitative concentration limits.

The level of airtightness is increasing in newly built Australian apartments. An appropriate ventilation rate is needed to provide occupants with a healthy environment. In 2022, a significant proposed change in the Australian National Construction Code (NCC) would require building tested as achieving less than five air changes per hour at 50Pa to have a continuous flow exhaust.

Schools had covered special attention in the last year, due to their importance to organize daily work as well as since most of the children were still not vaccinated. Under this circumstance, the importance of air renewal to reduce the probability of COVID-19 contagion inside buildings was highlighted. 

ASHRAE’s 2022 publication of a new position document on indoor carbon dioxide (CO2) has been a significant contribution to ongoing discussions of how indoor CO2 can be used to understand ventilation and indoor air quality (IAQ). The position document clarifies what is known about the relationship between CO2 concentrations and ventilation rates, the effects of CO2 on building occupants, and how CO2 concentrations relate to airborne infectious disease transmission. While the position document is a key step to addressing ongoing debate and

The purpose of this summary is to review Air Infiltration and Ventilation Centre activities, as reflected in its publications, related to indoor carbon dioxide over the 40 years that have transpired since its creation. These activities, like most applications of indoor CO2 to the fields of ventilation and indoor air quality, have focused on the following: control of outdoor ventilation rates, i.e., demand control ventilation; use as a tracer gas to measure outdoor air change rates; providing an indicator or metric of IAQ; and, directly impacting human health, comfort and performance.

The indoor air quality is very important for the well-being of occupants, especially in the case of young babies. This research focuses on the air quality of the surrounding air inside a crib with sleeping infants. To study the effects of different sleeping positions of the baby with in the crib a measurement setup was created in the laboratory. The breathing of an infant was simulated by means of a baby doll with air supply mixed with CO2 and measured at different sensor locations for different sleeping positions.