The MD6-ES24VK Outside Air Kit combines the MD6 with the ES24V to allow fresh, clean air to enter the building. The ES24V can command the central HVAC blower to help distribute fresh air through the existing duct work if necessary. It can be programmed to allow outside air to enter intermittently when the temperature is inside of your set temperature and humidity parameters. This prevents hot, humid, or freezing air from flooding your house all at once, while still meeting code.
The combination of the control and damper will help you meet ASHRAE 62.2 (2010/2013) and IRC (2012/2015) code standard requirements.