The freeze control option is recommended whenever the windmill is located away from the pond's edge. 

Anytime air is compressed, condensation is created and can accumulate in the pipeline. During freezing weather this condensation can freeze and stop the windmill from working. The freeze control option constantly checks line pressure. If the line starts to freeze, the control valve opens and feeds Ethanol alcohol (or rubbing alcohol) into the line which melts the ice. Then the valve closes and normal operation resumes.