Why Does Condensation Not Occur in Air-Conditioned Buses?

In summary, when exiting an air-conditioned bus in the summer, glasses often become misty due to condensation of water vapor. This is because the air inside the bus is both cooler and drier than the air outside. If the air conditioning system is further reducing the temperature inside the bus, then condensation will not occur because the system removes water vapor from the air, keeping the relative humidity low.
  • #1
Alan Tam
8
0
We should have experience that when we get off from an air-conditioned bus in the summer, our glasses become misty. It's due to condensation of water vapour on our cooler glasses. But why the condensation doesn't occur in the air-conditioned bus?
 
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  • #2
The air conditioner in the bus has the side effect of reducing the humidity inside the bus. The air inside the bus is both cooler and drier than the air outside.

- Warren
 
  • #3
Dear Warren, you mean the amount of water vapour in the bus have to reach certain level in order to condense? If the temperature in the bus is further reduced, will the water vapour condense eventally?

Alan
 
  • #4
For the glasses to become 'misty,' the glasss must be cooler than the surrounding air, and the surrounding air must be of high relative humidity. This occurs when the cooled glasses are taken into the humid air outside.

If the temperature of the bus is further reduced with an air conditioning system, then no, condensation will not occur on the bus. Air conditioning systems necessarily remove water vapor from the air as they cool it, and thus always keep the relative humidity fairly low.

- Warren
 

1. Why do I see condensation on the windows of regular buses, but not on air-conditioned buses?

Condensation occurs when warm, humid air comes into contact with a cooler surface, causing the water vapor in the air to turn into liquid droplets. Air-conditioned buses have a system that removes moisture from the air, making it less humid and reducing the likelihood of condensation forming on the windows.

2. Is the air-conditioning system in buses the same as the one in my home or car?

The air-conditioning system in buses is similar to the one in your home or car, but it may be designed specifically for larger spaces and may use different types of refrigerants. However, the basic principle of removing heat and moisture from the air is the same.

3. Can condensation occur in air-conditioned buses in certain conditions?

In some cases, if the air-conditioning system is not functioning properly or if the outside temperature is significantly different from the inside temperature, condensation can still occur in air-conditioned buses. However, it is less likely to happen compared to non-air-conditioned buses.

4. Why is condensation a problem in non-air-conditioned buses?

Non-air-conditioned buses do not have a system to remove moisture from the air. This means that the warm, humid air inside the bus can quickly come into contact with the cooler windows, causing condensation to form. This can make the interior of the bus feel damp and uncomfortable for passengers.

5. Is there a way to prevent condensation in air-conditioned buses?

To prevent condensation in air-conditioned buses, regular maintenance of the air-conditioning system is necessary to ensure it is functioning properly. Additionally, keeping the temperature inside the bus consistent with the outside temperature can also help reduce the likelihood of condensation forming on the windows.

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