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What is the Difference Between Internal and External Air Circulation for Heating?

1 Answers
JesseFitz
07/29/25 7:23am
The main differences between internal and external air circulation for heating are: Different thermal insulation effects: Internal circulation mode closes the airflow channel between the inside and outside of the vehicle. Without the blower, there is no air circulation, which helps maintain the interior temperature when using vehicle heating. External circulation mode uses the blower to draw outside air into the cabin, meaning there's airflow between the exterior and interior. In heating mode, the warm air inside the vehicle is more easily dissipated. Different fuel consumption: Using internal circulation during heating results in slower heat loss and lower fuel consumption. Using external circulation during heating leads to faster heat loss and higher fuel consumption.
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What are the symptoms of excessive valve clearance?

Excessive valve clearance mainly manifests in the following symptoms: 1. If the engine's valve clearance is too large, there will be continuous crisp sounds after starting the engine, which is most noticeable during cold starts. 2. Excessive valve clearance causes delayed opening and early closing of the intake and exhaust valves, shortening the intake and exhaust time, reducing the valve opening angle, altering the normal valve timing, resulting in insufficient engine intake and incomplete exhaust. 3. It also leads to a decrease in engine power, while causing impact and noise between components in the valve train, accelerating wear.
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How to Stop Windshield Wipers in the Middle Position?

Here are the steps to stop windshield wipers in the middle position: 1. First, power on the vehicle and activate the wiper function, setting the wipers to any speed setting. 2. Observe the wipers, and when they reach the desired middle position, turn the ignition key to the OFF position. This will cause the wipers to stop at the center of the windshield. Below is some extended information about wipers: 1. Windshield wipers, also known as wiper blades or windscreen wipers, are primarily used to remove raindrops and dust from the vehicle's windshield, thereby improving driver visibility and enhancing driving safety. 2. Due to legal requirements, almost all vehicles worldwide are equipped with wipers.
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Reasons for Car Wiper Malfunction?

Car wiper malfunctions are primarily caused by the following reasons: 1. Fuse blown: loose wires or poor contact; damaged or poor contact in the wiper control switch; armature winding open circuit or gear reducer. 2. Low voltage or poor switch contact: dirty contact surface between the wiper blade and glass; poor lubrication in motor bearings and gear reducer gears; poor brush contact or weak spring. 3. Wiper blade fails to self-reset: the wiper motor cannot stop at the automatic stop position, mostly due to a damaged control switch, poor operation of the automatic reset device, or an open circuit in the connecting wires.
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When to Turn on the AC in a Car?

When the weather is hot and you need to turn on the air conditioning to cool down, you can turn on the AC. Here is some introduction about the AC switch: 1. Car air conditioning is divided into cold air conditioning and hot air conditioning. Hot air conditioning does not require turning on the AC, you only need to turn on the blower to use the engine's heat for heating; while cold air conditioning requires turning on the AC switch to make the air conditioning compressor work to produce cold air. 2. In addition, mid-to-high-end car models will have an additional AUTO button, which means automatic air conditioning. When the AUTO button is turned on, the vehicle's computer will automatically identify whether to turn on warm air or cold air through temperature sensors.
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What Causes Engine Shaking After Shutdown?

Engine shaking after shutdown can be attributed to the following reasons: 1. Excessive carbon deposits: This can lead to pre-ignition and knocking, shortening the engine's lifespan and significantly reducing its power and fuel efficiency; 2. Carbon buildup on valves and their seat rings: Causes incomplete valve closure and air leakage, resulting in difficulties starting the engine, reduced power, and increased susceptibility to valve burning; 3. Carbon deposits and gumming in valve guides and stems: Accelerates wear between the valve stem and guide, potentially causing the valve stem to stick or seize within the guide, leading to valve sticking faults; 4. Carbon accumulation in piston ring grooves: Reduces or eliminates the side and back clearances of piston rings, causing them to lose elasticity and leading to cylinder scuffing. Carbon deposits on fuel injectors can cause uneven fuel injection among cylinders, resulting in engine shaking or misfiring.
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Which button is the heater in the car?

Depending on the vehicle model, the heater settings of the air conditioning system may vary. Here are the details: 1. The heater switch is usually displayed as a "thermometer" icon. Press the button to turn on the heater. 2. There are blue and red knobs on both sides. The red one is for heating, and the blue one is for cooling. By turning the knob, the red area gradually increases the temperature, while the blue area decreases it. Here is some information about the car air conditioning system: 1. The car air conditioning system is designed to cool, heat, ventilate, and purify the air inside the cabin. 2. It provides a comfortable environment for passengers, reduces driver fatigue, and enhances driving safety.
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