Fresh air economizers typically introduce what percentage of fresh air?

Fresh air economizers are designed to optimize indoor air quality while reducing energy costs by utilizing outside air for ventilation, particularly in milder weather conditions. The correct answer indicates that fresh air economizers typically introduce about 15-25 percent of fresh air into the system. This percentage is effective in ensuring that enough fresh air is circulated while minimizing the energy required to heat or cool that air.

Introducing this amount of fresh air helps to maintain proper indoor air quality, remove contaminants, and provide comfort without overburdening the HVAC system. If the percentage of fresh air were lower, indoor air quality might suffer due to inadequate ventilation, but if it were much higher, it could lead to energy waste as the system would have to work harder to condition the additional air. This balance is key for the operation of economizers, making the 15-25 percent range an optimal choice.