Should You Use Internal or External Air Circulation for Car Heating in Winter?
3 Answers
Whether to use internal or external air circulation for car heating in winter depends on the situation. For short trips, internal circulation is suitable; for long-distance driving, it is recommended to use external circulation to replenish fresh air. If driving in heavy traffic, internal circulation is advisable to prevent exhaust fumes from entering the car. During winter, car air conditioning is used almost daily for both heating and cooling. The heating principle of car air conditioning is much simpler than cooling. When heating, the engine's hot coolant flows through the heater core, and the air blown by the blower passes over the heater core, allowing warm air to flow out of the vents.
Whether to use recirculation or fresh air mode when heating in winter depends on specific conditions. From my daily driving experience, turning on recirculation immediately after starting the car can quickly warm up the cabin air while preventing cold drafts, saving fuel and heating faster - especially effective when driving alone. However, prolonged recirculation tends to cause window fogging, particularly during rain/snow or with multiple passengers, severely compromising visibility safety. Therefore, I always use recirculation briefly until warm, then switch to fresh air mode for a few minutes to defog and ventilate. Fresh air mode also reduces CO2 buildup, preventing drowsiness. Remember to use fresh air mode more frequently during highway or long-distance driving to ensure proper air circulation. In cold winters, wisely alternating these two modes maintains cabin comfort and safety. I recommend checking your car's climate control settings - if equipped with auto mode, use it for hassle-free intelligent management. The key is balancing heating efficiency with driving safety.
In winter, I prioritize using the external air circulation for heating. It draws in dry, cold air from outside, effectively preventing and clearing fog, which is crucial for visibility safety in damp and cold weather. It does feel a bit chilly at the start, so I briefly switch to internal circulation for about 5 minutes to warm up the cabin air. Once it feels comfortable, I switch back to external circulation. Prolonged use of internal circulation not only leads to faster fogging but also deteriorates air quality, making you feel tired and dizzy during long drives, especially when there are children or elderly passengers. External circulation ensures fresh air, enhancing driving comfort. Although it heats up a bit slower in terms of fuel consumption, safety comes first. Avoid setting the heating temperature too high to save fuel. It's advisable to use the defogging button in combination; heavy fog can be quickly resolved by switching to external circulation. When driving on icy or snowy roads, clear windows are key to safety.
