Operational temperature from 25°F to 175°F (user adjustable from 25°F to 110°F) activated when inside temperature is from 6°F to 30°F (user adjustable) more than the outside temperature. The controller will not activates fan when outside relative humidity is above 85%. The controller activates fan when humidity inside is 12% or more then the humidity outside. The humidity venting is independent from the temperature venting. The venting based on the humidity will take place in temperature from -40°F to 175°F. The venting based on temperature and humidity will not take place when outside humidity is above >85%. Recomended for attics when an excessive humidity is a problem.