The Lesser of Two Evils

[Guest guest]

Assuming no VOC or offgassing problem which of the two secnarios is

worse

1)A building peaking each day at 1500 ppm CO2, rh under 50%, spores

less than ambient air

2)A Building peaking at 700 ppm CO2, 75% RH, spores 3000 to 5000

counts per cubic meter predominantly Penicilium/Apsergillus while

ambient air count approximatley 70 per cubic meter predominately

ascosproes and ganoderma.

1 sure sounds a lot better than 2 in my opinion.

Ambinet CO2 will float 400 to 450 ppm so this would be exceeding

ambinet plus 700. Funnything with ambient plus 700, you could have

urban traffic gridlock and exceed 600 ppm CO2 outside, then be 1300

ppm inside and somehow compliant

[Guest guest]

Funnything with ambient plus 700, you could have

urban traffic gridlock and exceed 600 ppm CO2 outside, then be 1300

ppm inside and somehow compliant

If that is the case, all things being equal with no significant indoor contaminant sources other than bioeffluents, I'd rather see indoor CO2 levels rise even higher than bring in more fine and ultrafine particulate from urban traffic gridlock. What becomes critical in these urban buildings is very good filtration of outdoor air, which I find to be rare. Higher ventilation rates with filter bypass occuring or with the use of operable windows in these urban locations can result in a degradation of IAQ.

While I do believe that elevated indoor CO2, itself, is capable of causing negative health effects (i.e., not just a surrogate indicator of ventilation), infiltration of PM2.5 is the greater evil.

Steve Temes