Should You Use Internal or External Air Circulation When Sleeping in a Car?
2 Answers
When sleeping in a car, you should use external air circulation to ensure proper air flow inside the vehicle. Here are detailed explanations about internal and external circulation: 1. External Circulation: This mode uses a fan to draw outside air into the car. Even when the fan is off, moving the vehicle will naturally draw in outside air, replenishing fresh air inside. However, during urban traffic congestion, using external circulation may fill the car with exhaust fumes as it draws in polluted air from surrounding vehicles. 2. Internal Circulation: This mode effectively blocks external dust and harmful gases from entering the vehicle. It's particularly useful when driving through smoky, dusty, or odorous areas, or in heavy traffic where it prevents inhalation of exhaust from preceding vehicles. Another benefit is maintaining interior temperature.
I'm used to driving long distances and often take naps in the car. Based on experience, using the external air circulation mode is more reliable because if the air inside the car doesn't circulate, the carbon dioxide concentration will increase, leading to dizziness and chest tightness after prolonged sleep, especially with the windows and doors tightly closed. Imagine, using the internal air circulation mode cools or heats up faster, but the air circulates in a limited space, making it harder to breathe, and in severe cases, it may cause oxygen deprivation. It's recommended to set the air conditioning temperature properly. In external air circulation mode, fresh air can come in, making you feel more comfortable. If the outdoor air is poor or too hot/cold, you can briefly switch to internal air circulation for adjustment, then switch back. Remember to crack the window slightly for safety first, to avoid accidents. Park and sleep at highway service areas or safe places, don't take risks by the roadside.
