During the second experimental cycle it was observed that the highest total VOC’s
concentrations in Office 1 appeared when the A/C unit was operating and all doors and
windows were closed (160 µg m-3 at 19/12/05) indicating high recirculation rate. Furthermore,
when smoking was allowed (13/1/2006) the total VOC’s levels did not exceed the specified
limit values reaching 205 µg m-3 even though for the biggest part of the day all windows and
doors were kept closed. The concentrations were even lower the rest of the experimental
period ranging at 55 µg m-3. CO2 and classical pollutant (not shown here) concentrations
remained at similar levels with the previous cycle indicating acceptable indoor conditions. On
the other hand PM10 and PM2.5 concentrations presented significant increase reaching 358
and 136 µg m-3 (Office 1, 4/1/06) and 337 and 177 µg m-3 (Office 1, 13/1/06) respectively,
when smoking was allowed and indoor conditions were controlled (see Table 3). Similar
behaviour was found in Office 2 regarding all pollutants measured. However, total VOCs levels
were higher, reaching 306 µg m-3 and CO2 was elevated, not exceeding the 1800 mg m-3 limit
however, which may be attributed to its smaller size compared to the number of occupants
(Table 3). Moreover, the particles concentrations were also similar compared to Office 1.
Finally, in both offices CO levels were not elevated.