First and second IAQ sensors are located within a building and are configured to measure first and second IAQ parameters, respectively, the first and second IAQ parameter being the same one of: relative humidity; amount of particulate; amount of volatile organic compounds; and amount of carbon dioxide. A mitigation device is separate from an HVAC system and includes a control module configured to turn the mitigation device on and off based on the first IAQ parameter, the second IAQ parameter, and whether the HVAC system is on or off. A mitigation module is configured to selectively turn the HVAC system on and off based on the second IAQ parameter, the first IAQ parameter, and whether the HVAC system is on or off.