A Review of Studies of Ventilation and Indoor Air Quality in New Homes and Impacts of Environmental Factors on Formaldehyde Emission Rates From Composite Wood Products

While increasing outdoor air ventilation rates does reduce the indoor concentrations of air contaminants with indoor sources, the actual reductions in concentrations can differ significantly from those calculated with the assumption of a constant indoor emission rate. The ratio of actual to predicted concentration reductions for the low to high outdoor air ventilation modes ranged from 0.59 for formaldehyde to 1.37 for benzaldehyde. Increases in emission rates for compounds such as formaldehyde are consistent with mass transfer theory for emissions from materials such as composite wood where mass transfer is limited by gas-phase diffusion across the boundary layer. Decreases in emission rates of compounds such as d-limonene were surprising and may be the result of residual emissions of cleaning chemicals which were used by the occupants prior to the tests