E-Books →Stylish Spins The Complete Ceiling Fan Design Guide

In addition to the thermal comfort benefits of increased air speeds, ceiling fans can also improve air distribution, working in concert with the HVAC system to provide the desired thermal conditions more consistently throughout a space. When correctly designed and operated, ceiling fans support the HVAC system to minimize temperature gradients within a space, providing more consistent temperature and air quality conditions throughout a space. This improved air distribution can be effective for both heating and cooling scenarios. For example, ASHRAE Standard 62.1 - Ventilation for Acceptable Indoor Air Quality lists a ventilation effectiveness of 0.8 for ceiling-supplied warm air systems (due to stratification of the warm air near the ceiling), but adding ceiling fans in this scenario brings the ventilation effectiveness back to 1.0, or fully mixed condition, reducing the amount of outside air required.
Improved Air Distribution
By increasing air movement and improving air distribution in a space, ceiling fans also improve air quality. The increased air movement prevents the sensation of stale or stuffy air, and can help dissipate odors. One recent study has also documented a measurable air quality improvement from ceiling fans by dissipating CO2 and other exhaled pollutants that would otherwise gather near occupants in still air conditions. Large-scale studies of occupant survey data indicate that occupants would prefer more air movement than they have, especially in conditions where occupants report feeling warm, as illustrated in Figure 4.
Improved Air Quality