If things heat up the faster their particles are moving, why is the air a fan pushes cooler?
In: Physics
Heat coming off of you sticks to your body so to speak. The fan is pushing that self generated heat off of you.
The air it pushes isn’t cooler. It feels cooler to you because it absorbs some of the heat your body produces and pushes it away from you, allowing more heat to transfer to the air, leaving your body.
you dont feel temperature.
You feel the rate at which heat is leaving your body.
In still air, this is the temperature difference between your skin and the air, but when the air is moving, the air caries away more heat.
The heat added by the fan is negligible, but the rate heat is removed is greatly increased.
Feeling it cooler vs actually being cooler are different things. Moving air only feels cooler because it evaporates more moisture on your skin
The air that a fan pushes isn’t cooler, it only feels cooler because it is flowing past you and absorbing heat from your skin as it passes. This is the same concept as the wind chill outside. The fan actually does slightly warm up the air that it moves, a fan that uses 60 watts of electrical energy adds the same amount of heat to a room as a 60 watt light bulb.
Fans don’t make the air cooler at all, they just make the thing they’re blowing on cooler, IF it’s hotter than the ambient air. It just gives a steady supply of fresh room-temperature air for a hot thing to dump its heat into. And in the case of cooling down humans, there’s the added benefit of increased sweat evaporation which enhances your body’s cooling abilities even more.
The air from a fan is not a cooler temperature. Increasing the air flow increases the amount of thermal energy that can be moved away. Heat will always “want” to equalize at the lowest temperature available. Normal body temperature is 98.6°f. So if the air temp is lower. Then the heat from the body can be pulled away into the air. The more airflow there is. the more heat transfer can occur. Sweating increases this effect as sweat helps to move away more heat. This process results in a cooling feeling. Until the air is at a higher temperature.
The fan pushes the gas molecules to move faster in a single direction, and that speed increase is very small compared to the increase of the molecule speeds of a temperature increase.
The fan air cools you by two ways, 1] carrying away more heat because the air is already cooler. If the air is hotter than body temperature it will heat you up faster. 2] if you have sweat on your skin, it will carry away more sweat, which uses body heat to evaporate more sweat and cool you down.
Velocity and Pressure!
One reason fan air is cooler is because the increased velocity causes a less matter within an area. If each flowing particle has the same energy as the particles of stagnant air, but there were less particles in an volume => less energy in that volume => lower temperature => it’s cooler!
Whenever you think of heat/temperature, ALWAYS think about what’s happening with pressure!
It’ll usually help explain some of the “missing” things! (Pressure-temperature are deeply connected just like electromagnetism)
Fans don’t cool. All in all they slightly heat thins up even.
What fans do is to push air around.
Your body cools down by sweating and you can enhance that function by increasing air flow against your skin.
Moving air isn’t actually cooler but it allow your body to transfer heat more easily.
This is similar to how a hot bench made of metal and one made out of wood will feel differently hot when you sit on them despite being the same temperature.
We don’t actually feel temperature we feel the amount of heat we transfer to or away from out body.
Latest Answers