Indoor Air Quality (IAQ) refers to the air quality within and around homes and structures, especially as it relates to the health and comfort of home residents. Understanding and controlling common pollutants indoors can help reduce your risk of indoor health concerns. American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends temperatures ranging from 68.5 to 75 degrees Fahrenheit in the winter, and from 75 to 80.5 degrees in the summer; indoor relative humidity should be maintained at or below 65%. The EPA recommends humidity levels of between 30% and 60% to reduce mold growth. Any excess moisture, volatile organic compounds, carbon monoxide, and radon are four major indoor air pollutants. They result in damp and stuffy houses. Thus, indoor air is more harmful than outdoor air.