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Author Topic: Do smells travel further in warm air?  (Read 5697 times)

Offline thedoc

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Do smells travel further in warm air?
« on: 28/07/2013 07:30:02 »
Andrew B. Roberts  asked the Naked Scientists:
   
Does smell / odour travel further in warm air than cold air ?

Best Regards,

Andrew

What do you think?
« Last Edit: 28/07/2013 07:30:02 by _system »


 

Offline CliffordK

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Re: Do smells travel further in warm air?
« Reply #1 on: 28/07/2013 09:09:04 »
I would think your nose would work better in warm air than in cold air.

Various bacteria and decomposers may also be more active during hot summer days than during cold winter days.
 

Offline alancalverd

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Re: Do smells travel further in warm air?
« Reply #2 on: 28/07/2013 13:41:37 »
The odor molecules have more energy at higher temperatures so the rate of emission of odor from a given nonbiological source will also increase but the viscosity of air also increases with temperature so the odor will not spread as quickly.

Could be a fun experiment for a school demonstration.
 

Offline chiralSPO

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Re: Do smells travel further in warm air?
« Reply #3 on: 17/08/2013 17:06:04 »
I'm pretty sure air gets less viscous as it heats up, not more (I am assuming that the pressure is constant, since we are discussing an open classroom).

The mean free path of the molecule will certainly increase with temperature (they are proportional), so the rate of diffusion will also increase.

Also, warm air usually means the source of the smell is warmer, which will increase the vapor pressure of any smelly compound(s). This will increase rate at which the smell gets into the air as well as how quickly it disperses and how far away it will be detectable.
 

Offline Bored chemist

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Re: Do smells travel further in warm air?
« Reply #4 on: 17/08/2013 19:14:11 »
I'm pretty sure air gets less viscous as it heats up, not more
I'm not.
 

Offline dlorde

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Re: Do smells travel further in warm air?
« Reply #5 on: 19/08/2013 12:28:41 »
I'm pretty sure air gets less viscous as it heats up, not more...
Why rely on guesswork? According to a reliable source, air viscosity increases with temperature.
 

Offline chiralSPO

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Re: Do smells travel further in warm air?
« Reply #6 on: 19/08/2013 22:39:38 »
I stand corrected!
 

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Re: Do smells travel further in warm air?
« Reply #6 on: 19/08/2013 22:39:38 »

 

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