In general, lower ventilation rates are associated with increased adverse health effects. The effects of ventilation rates on the prevalence of sick building syndrome (SBS) symptoms have received the most study. In recent reviews of the scientific literature.

• SBS symptoms

In 20 of 27 studies found that the prevalence of one or more SBS symptoms increased at lower ventilation rates and nine studies found that the prevalence of at least one symptom was increased by >80% at the lower ventilation rate. The benefits of increasing ventilation rates above 20 cfm per person were less consistent than the benefits of increasing ventilation rates to 20 cfm per person. LBNL-43334, Association of ventilation rates and CO₂ concentrations with health and other responses in commercial and institutional buildings.

Figure 4. Probable Explanation for Association of Ventilation Rate with Health (Committee on the Assessment of Asthma and Indoor Air 2000)

• Common Colds and Sick Leave

Four of four studies have found that lower ventilation rates were linked to increased respiratory illnesses such as common colds and influenza or either increased absence from work. The study of absence rate found a 50% increase in short term absence at 24 cfm per person relative to 48 cfm per person. LBNL-47458