In the last two decades, Indoor air quality becomes a very important topic of discussion in HVAC industry. The U.S. EPA considers indoor air quality to be among the top 4 environmental health concern in the United States. This session will cover, why IAQ is very important, what is the cause to poor IAQ, discuss the solution to poor IAQ, and how is it related to energy. This course is approved by the Iowa Plumbing and Mechanical Systems Board to fulfill two hours of continuing education discipline for HVAC and mechanical license renewal.