(2017b) found that temperature had a greater effect on the release of VOCs from three-layer plywood than did relative humidity or the air-exchange rate
. However, few reports have focused on the odors from wooden panels.
Build-up of oily residue inside IBC exhaust ducts will gradually reduce the air-exchange rate
and cooling capacity of the IBC system.
Note, however, that the latter assumes an increase in air-exchange rate
alone, without increasing the mass-transfer coefficients, which would tend to increase as ventilation increases.
Some nonresidential buildings (such as the buildings contaminated in the 2001 attack) have extremely high ceilings, and achieving a high air-exchange rate
in these spaces may be not be feasible with portable air cleaners.
The higher the air-exchange rate
, the greater the indoor ozone level, according to Weschler's data.
Risk factors for infection among the lab workers included missed TB diagnoses in patients in the first 24 hours of admission, (45% of cases; odds ratio 2.0), delayed treatment for TB by 1 week or more (30% of cases; odds ratio 2.0), high proportion of hospital TB deaths (12% of patients died; odds ratio 2.5), and working in pathology, which has low air-exchange rates
(51% of evaluated areas; odds ratio 5.4).
Obviously, it would take a keen eye (or nose) to link these circumstances to a real IAQ problem, which is why it's important to upgrade your building automation system to include proper filtering, air-exchange rates
"By sealing windows and doors to keep inside air in and outside air out, we've reduced the air-exchange rates
by a factor of two or more in many new houses," says Richard Corsi, associate professor of civil engineering at the University of Texas and one of the country's leading experts on indoor air quality.
Their double-blind, crossover study altered air-exchange rates
at four buildings with sealed windows and mechanical ventilation systems every Friday afternoon for three two-week recording periods.
It has been demonstrated that emission factors change with changes in air-exchange rates
, increasing at high air-exchange rates
and decreasing at low air-exchange rates
(Matthews et al.