Methods of fog control for a vehicle windscreen before vehicle moving off

INTRODUCTION: In any type of vehicle, the accessory equipment system of air heating and conditioning should ensure safety by means of glazing protection from fogging with high operational speed and minimal energy consuming, as driver’s reaction slows down in low visibility conditions and the risk of road accidents increases.

AIMS: Analytical review of state-of-the-art methods of efficiency improvement of condensate cleaning from the inner surface of a vehicle windscreen in order to discover promising methods of fog control before vehicle moving off which are energy efficient and driver- and passenger-friendly.

LINE OF RESEARCH: Review of publications, dedicated to issues of condensate cleaning and vehicle glazing prevention from fogging.

METHODS: Study and analysis of papers in the mentioned area, published in open sources.

RESULTS: Conditions of fogging on inner surfaces of vehicle glazing are discussed. Russian and foreign regulatory documents, featuring demands to the procedure of fog cleaning from the windscreen inner surface, are given. Special aspects of air drying in cabin of electric vehicles and ICE-driven vehicles and various methods of the windscreen inner surface heating are considered.

CONCLUSIONS: Efficiency of windscreen condensate cleaning may be increased significantly by means of conjuction of such methods as: a) making inner surfaces of vehicle glazing hydrophobic; b) defroster design optimization in order to ensure air supply having minimal pressure losses, maximal output mass, high speed and uniform distribution of airflow along the surface of critically important fields of view; c) using of tempered windscreens with transparent electrically-conducting layer; d) drying of vehicle cabin air. At present, the search for efficient methods of windscreen warming and cabin air drying in recirculation mode for both electric vehicles and ICE-driven vehicles, operating in low air temperature conditions, continues.