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vmars316
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Hello & Thanks,
Is it possible to use only a powerful fan
without a compressor to make very cold air ?
Thanks
Is it possible to use only a powerful fan
without a compressor to make very cold air ?
Thanks
What do you think? Why would the air coming out of the fan be colder than the air going into the fan?vmars316 said:Hello & Thanks,
Is it possible to use only a powerful fan
without a compressor to make very cold air ?
Thanks
Yes, obviously,phinds said:What do you think? Why would the air coming out of the fan be colder than the air going into the fan?
Obviously WHAT?vmars316 said:Yes, obviously,
why would any point be colder than any other point?But I am thinking of a fan blowing into a funnel shaped thing
where the speed of the air increases as it goes thru
the very narrowest end of funnel shaped thing .
And if the funnel was made of iron
I am wondering where on that funnel would be the coldest point ?
vmars316 said:But I am thinking of a fan blowing into a funnel shaped thing
where the speed of the air increases as it goes thru
the very narrowest end of funnel shaped thing .
And if the funnel was made of iron
I am wondering where on that funnel would be the coldest point ?
Where would the coldest point begin (before it spread) ?
jartsa said:If air inside vacuum cleaner's hose has mass 0.01 kg and its speed is 10 m/s, then
the air has kinetic energy 0.5 J.
That air's thermal energy is reduced by the amount of its kinetic energy, 0.5 J. That means that the air in the hose is just a little bit cooler than the air in the room where the vacuum cleaner is.
Because the cold has a starting point .phinds said:Obviously WHAT?
why would any point be colder than any other point?
phyzguy said:This is just wrong. Center of mass energy is independent of thermal energy. Do you think astronauts get colder and colder as they accelerate into space?
This sort of question has come up before. First, a "fan" and a "compressor" are similar devices physically, having the same basic purpose and in many cases operating principle; to move air by increasing its pressure. The terminology difference is typically just based on how much pressure they can provide.vmars316 said:Hello & Thanks,
Is it possible to use only a powerful fan
without a compressor to make very cold air ?
Thanks
I really don't have any idea what you mean by this. What does it mean for the cold to "begin"? Some effect has to make the air colder - what effect do you think that is?But I am thinking of a fan blowing into a funnel shaped thing
where the speed of the air increases as it goes thru
the very narrowest end of funnel shaped thing .
And if the funnel was made of iron
I am wondering where on that funnel would be the coldest point ?
Where would the coldest point begin (before it spread) ?
[separate post]
Because the cold has a starting point .
Think about it :
Suppose the funnel is made of a stack of iron rings .
Each ring having a smaller diameter than the ring above it .
And in between each ring is a ring of an insulating material
keeping the cold from spreading .
Again , where does the cold begin ?
This sounds rightjartsa said:We just need to create a place we the compressed air can expand into. Then the compressed air does work and cools.
The can gets cold because it contains a chemical liquid that boils at below room temperature and a certain pressure. So when you spray it, the chemical boils and that absorbs heat, making the can cold.vmars316 said:This sounds right
But :
When I use a can of bug spray ,
the can in my hand gets cold .
I don't know if the spay is cold or not (too toxic to check it out) .
But the hole in the nozzle is much smaller that the tube leading to it .
So there is work being done there also as air is released into the atmosphere...
What's going on there exactly ?
As mentioned by @russ_watters , the can contains some liquid that becomes gas.vmars316 said:This sounds right
But :
When I use a can of bug spray ,
the can in my hand gets cold .
I don't know if the spay is cold or not (too toxic to check it out) .
But the hole in the nozzle is much smaller that the tube leading to it .
So there is work being done there also as air is released into the atmosphere .
What do you mean by "compressed air can"? Do you mean the small cans that you use to blow dust off computer keyboards and other electronics? Those use a liquid hydrocarbon too...jartsa said:As mentioned by @russ_watters , the can contains some liquid that becomes gas.
But what if we let out half of the contents of a compressed air can? The can gets cool, right?
So it must be so that the gas in the can is doing work as it is expanding. Only work there is to do is to push the gas that is going out, push it from the back, so to speak.
russ_watters said:What do you mean by "compressed air can"? Do you mean the small cans that you use to blow dust off computer keyboards and other electronics? Those use a liquid hydrocarbon too...
So you are saying that the insect spray contains freon ?russ_watters said:The can gets cold because it contains a chemical liquid that boils at below room temperature and a certain pressure. So when you spray it, the chemical boils and that absorbs heat, making the can cold.
Not freon. The MSDS for Raid, for example, says it contains 10-30% isobutane, some propane and a couple of other hydrocarbons.vmars316 said:So you are saying that the insect spray contains freon ?
Why would it contain freon...
Because liquids are denser than gases so you can fit more in the can..instead of just compressed air ?
Well the law of conservation of energy is a law that always applies.vmars316 said:And what is the name of the law that says
When compressed air does work it cools ?
A powerful fan without a compressor is a type of fan that uses only electricity to generate air movement, without the use of a compressor or refrigerant. It is often used as an alternative to traditional air conditioning systems.
A powerful fan without a compressor works by using a motor to spin blades that push air through the fan. This creates a breeze that can help cool a room or space. Unlike traditional air conditioners, it does not use a compressor to cool the air.
There are several benefits to using a powerful fan without a compressor. It is more energy-efficient, as it does not use a compressor or refrigerant. It is also more environmentally friendly, as it does not release harmful chemicals into the air. Additionally, it is more affordable and easier to maintain compared to traditional air conditioning systems.
Yes, a powerful fan without a compressor can cool an entire room. However, it may not be as effective as a traditional air conditioner in extremely hot or humid conditions. It is best used in smaller spaces or in combination with other cooling methods.
The noise level of a powerful fan without a compressor can vary depending on the specific model and speed setting. However, in general, they tend to be quieter than traditional air conditioners since they do not have a compressor. Some models also have noise-reducing features, such as blade design or insulation, to further minimize noise.