Finding F-0525

“The results shown in Figure 4 indicate that the CO2 concentration in many houses with combustion heating equipment (i.e., ID 15–24) had risen significantly since December 2020, reaching between 3500 ppm and 5000 ppm (in rare cases), as compared to houses without combustion heating.”

Hattori et al. Investigation of Indoor Air Quality in Residential Buildings by Measuring CO2 Concentration and a Questionnaire Survey (2022). Sensors (Basel, Switzerland). Page 7. CKB 8777

Structure

Source: Unvented heaters
Factor: Carbon dioxide (CO₂)
Population: households
Setting: living room, JP
Study design: field investigation of CO2 concentration in 24 occupied houses in urban Japan (October 2020 to the following winter) with a questionnaire survey, comparing houses with and without combustion (kerosene) heating (class 4)
Sample: 24 homes
Caveat: the sentence opens with a reference to Figure 4, but states its own result; the heaters are kerosene heaters per the housing table, filed under unvented-heaters

A Finding records what one published document states, verbatim and with its page. It is not a conclusion of Coridum; see the Claims that build on it.