The answer to 'humidifier blowing cold air' is that this is likely due to a malfunctioning humidifier. A humidifier that is blowing cold air instead of warm, moist air is usually a sign of an issue with the heating element or thermostat within the unit. This can be caused by a variety of factors, including mineral buildup, a faulty component, or a problem with the humidifier's control system.
If your humidifier is blowing cold air, the first step is to check the settings and ensure that the unit is powered on and set to the appropriate humidity level. You can also try cleaning the unit according to the manufacturer's instructions to remove any mineral deposits that may be interfering with the heating element. However, if the issue persists, it's best to call in a professional HVAC technician to diagnose and repair the problem, as attempting to fix the humidifier yourself could potentially cause further damage.