Abstract
A mathematical model (CHemistry with Aerosol Microphysics (PyCHAM)) is extended from including detailed gas-phase chemistry with dynamic gas-particle and gas-single surface (e.g. wall) partitioning to also including surface reactions, partitioning to multiple surfaces and wavelength-dependent transmission of natural light. The improved PyCHAM can simulate physicochemical processes occurring indoors.
The combination of processes now simulated in PyCHAM alongside relatively detailed chemistry is novel compared to alternative models. Furthermore, PyCHAM is open-source and includes a user-friendly interface and manual (PyCHAM (2023)). Here we present the ability of PyCHAM to reproduce observations from indoor environments and provide additional insight.
In particular, we compare against observations in homes that target processes affecting indoor air quality: gas-surface partitioning (e.g. Figure 1), surface reactions, light transmission through windows, particle deposition to surfaces, indoor emission of gases and particles, indoor-outdoor exchange of gases and particles. In Figure 1 of this abstract is an example of PyCHAM reproducing observations: when semi-volatile organic components (SVOC) are present on indoor surfaces and allowed to partition into the gas-phase and then the particle-phase, indoor particle concentrations of organics (separated by alkane-equivalent volatility bins (carbon number (C) 24-31)) increases as the mass concentration of particles with diameter less than 2.5 μm (PM2.5) increases. The same trend, with comparable gradient (m), is reported in observations from a recently occupied household (Lunderberg et al (2020)).
As an example of the detail available from PyCHAM, we report the role of Highly Oxygenated Molecules (HOMs) on particle loading and oxidation state, since chamber studies indicate HOMs can significantly affect these properties (Kruza et al (2020)). The role of HOMs is investigated over several cases in which the following variables are changed within published ranges: surface deposition of ozone; surface reactions affecting ozone, nitrogen oxides and nitrous acid; source strength of indoor and outdoor particulates; source strength of indoor and outdoor gases.
The combination of processes now simulated in PyCHAM alongside relatively detailed chemistry is novel compared to alternative models. Furthermore, PyCHAM is open-source and includes a user-friendly interface and manual (PyCHAM (2023)). Here we present the ability of PyCHAM to reproduce observations from indoor environments and provide additional insight.
In particular, we compare against observations in homes that target processes affecting indoor air quality: gas-surface partitioning (e.g. Figure 1), surface reactions, light transmission through windows, particle deposition to surfaces, indoor emission of gases and particles, indoor-outdoor exchange of gases and particles. In Figure 1 of this abstract is an example of PyCHAM reproducing observations: when semi-volatile organic components (SVOC) are present on indoor surfaces and allowed to partition into the gas-phase and then the particle-phase, indoor particle concentrations of organics (separated by alkane-equivalent volatility bins (carbon number (C) 24-31)) increases as the mass concentration of particles with diameter less than 2.5 μm (PM2.5) increases. The same trend, with comparable gradient (m), is reported in observations from a recently occupied household (Lunderberg et al (2020)).
As an example of the detail available from PyCHAM, we report the role of Highly Oxygenated Molecules (HOMs) on particle loading and oxidation state, since chamber studies indicate HOMs can significantly affect these properties (Kruza et al (2020)). The role of HOMs is investigated over several cases in which the following variables are changed within published ranges: surface deposition of ozone; surface reactions affecting ozone, nitrogen oxides and nitrous acid; source strength of indoor and outdoor particulates; source strength of indoor and outdoor gases.
Original language | English |
---|---|
Pages | 1-1 |
Number of pages | 1 |
Publication status | Published - 5 Sept 2023 |
Event | European Aerosol Conference, Malaga, 2023 - Spain, Malaga Duration: 3 Sept 2023 → 8 Oct 2023 |
Conference
Conference | European Aerosol Conference, Malaga, 2023 |
---|---|
Abbreviated title | EAC 2023 |
City | Malaga |
Period | 3/09/23 → 8/10/23 |
Keywords
- Indoor air quality (IAQ)
- Gas-particle interaction
- Numerical modelling