metrics

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.

The Airborne Infection Reduction through Building Operation and Design for SARS-CoV-2 (AIRBODS ) project aim is to deliver guidance on the ventilation operation and future design of non-domestic buildings and to quantify the risk of, and reduce the transmission of SARS-CoV-2 in buildings. It is doing this through experimentation, computer simulation and fieldwork supporting the guidance and tools.

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.

Indoor carbon dioxide (CO2) concentrations have been used for decades to evaluate indoor air quality (IAQ) and ventilation. However, many of these applications reflect a lack of understanding of the connection between indoor CO2, ventilation rates and IAQ. In particular, a concentration of 1800 mg/m3 (1000 ppmv) has been used as a metric of IAQ and ventilation without an appreciation of its basis or application.

Buildings represent a major end use of energy throughout the world and are typically the dominant sector for electricity.   The use of that energy is to provide buildings services, the most important of which is Indoor Environmental Quality (IEQ).  Heating and air conditioning systems typically handle the thermal comfort aspects of IEQ; the energy impacts and economics of such systems is well studied.  The most important remaining aspect of IEQ is Indoor Air Quality (IAQ).

Indoor carbon dioxide (CO2) concentrations have been used for decades to purportedly evaluate indoor air quality (IAQ) and ventilation. However, many applications of CO2 as a metric have reflected a lack of understanding of the connection between indoor CO2 levels, ventilation and IAQ. In many cases, an indoor concentration of 1800 mg/m3 (1000 ppmv) has been used as a metric of IAQ and ventilation without understanding its basis or significance.