Questions tagged [cooling]
The cooling tag has no usage guidance.
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Vibrational states vs levels
I am trying to understand Raman cooling and my difficulty is pretty much what the question says: what is the difference between a vibrational state and a vibrational level?
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2answers
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Why is the rate of energy conducted in a rod equals the rate of energy released from the surface at the other end?
Assuming energy is released as convection only,we always do questions by equalizing,
$$P_{\text{conducting}} = Q/t = KA (T1 - T2)/L = eA(dT).$$
Assume the system is at Steady State. Why does this ...
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Doppler cooling Ethanol
Is it possible to use laser cooling to cool Ethanol in it's gas phase? I've seen research on IR diode cooling when you reverse the electrodes but laser cooling was/has always been limited to atoms and ...
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1answer
56 views
Is my modification of Newtons Law of Cooling an infraction?
I'm working on temperature prediction and therefore also cooling. I stumbled upon Newton's Law of Cooling (NLC) and I do like its simplicity, but I'm not so happy about the condition that the ...
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1answer
55 views
Why does steam exiting a pressure cooker valve feel cool to the touch?
I made the surprising discovery that steam escaping a pressure cooker through a screw-valve on top of the pot feels relatively cool: I can comfortably place my hand on the steam without getting burnt....
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1answer
51 views
Accuracy of Newton's law of cooling
I've made an experiment to verify Newtn's law of cooling, but while doing the analysis, my results don't fit accurately with the data collected (303 data using a sensor). According with my initial ...
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20 views
Thermoelectric cooler's Qmax cites maximum heat transfer — how is it so close to rated wattage considering TEC's low efficiency?
Some background regarding my question:
I'm thinking if making some sort of TEC-based ice cream maker. Considering the combined specific heat capacities, I calculated (possibly incorrectly) the value ...
2
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1answer
56 views
Is it possible to cool down air with warm water?
Is there some condition in wich the water evaporation can cool down the air even if the water is hotter than the air?
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1answer
47 views
Why is it hard to cool a mini-PC to room temperature?
I have this passively cooled mini-PC that froze every few days. After a lot of investigation I realized that it was overheating (running android studio and such) so I bought a fan, an arduino nano and ...
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48 views
Heat dissipation in space - how do they do that?
Consider a space aircraft. During its propulsion, I believe a lot of heat is transmitted to the aircraft by simple contact with the motor. But in space, there is no air to cool the aircraft. The only ...
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27 views
Can cooled gasses be bubbled up through water to cool it?
I'm working with a pressure vessel that is cooled to a reasonably cool temperature. Since it is cooled at pressure when the air exits the pressurized system the gas expands and thus cools a great deal ...
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173 views
Energy-optimal beer cooling
Suppose that I am going to host a big party one month from now, and I have various liters of cold beverages that will need to be refrigerated by the time of the party. I have a fridge at home (which ...
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1answer
55 views
What is the Festina Lente Regime?
I am studying BEC formation without evaporative cooling, so realized only thrpugh optical means.
One of the problems to face is "photon reabsorption": an atom absorbs a photon of the laser ...
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1answer
71 views
Air conditioner on rainy day [closed]
I got a new LG 1.5 ton AC(Air conditioner) . It's summer time here and the temperature reaches approx 40 degree Celsius at peak time. And it's working quite satisfactorily. But in the last two weeks ...
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1answer
76 views
Can a fan in a room cool down objects?
Does a fan cool objects? I have a ceiling fan in my office which really helps to keeps the room cool. Does it also cool down vitamins in a plastic bottle with a screw on top? My office can get very ...
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0answers
17 views
Initial and final pressures for the Joule-Kelvin expansion?
The Joule-Kelvin (or Joule-Thomson) expansion is an isenthalpic expansion in which the reduction of a gas' pressure from $ P_{i} $ to $ P_{f} $ results in a change in Temperature. It results in ...
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31 views
Temperature drop along silicone tube
I would like to ask your help to calculate the temperature drop of a fluid (at a specific conductivity) that flows in a silicone tube at different rates. This is a real case and I expect to perform ...
3
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2answers
477 views
Open window in hot room, how fast will temperature equalize? [closed]
I am currently sitting in a warm room. I just opened a window to the outdoors, where it is cooler.
Middle school science says the warm air should move toward the cool air, which should (in theory) ...
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33 views
Random walks and the Doppler limit in laser cooling
I have a question about some conflicting definitions I have encountered regarding the diffusion coefficient in random walks of laser cooled atoms. I was wondering if someone here may be able to clear ...
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1answer
18 views
Will a consumer freezer survive air travel with a pressurization/depressurization cycle?
Is it possible to ship a consumer freezer by air cargo (such as this one: https://www.danby.com/products/freezers/dcf072a2wp/ )? Or will the refrigerant gas expand too much and break the freezer? We ...
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1answer
71 views
Cooling something by applying a decreasing temperature
I've recently come across Fourier's Heat Equation: $k \cdot \nabla^2 \; T = \rho c \cdot \dot{T}$ and the solution to Newton's Law of Cooling: $T(t)=\left(T_\text{initial} - T_\text{cool}\right) \cdot ...
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1answer
50 views
Is it possible that an instant coffee 3 in 1 (or any other type of coffee) is cooling faster than tea?
I have observed a strange phenomenon. I my mouth is very sensitive to very hot liquids (like, freshly made tea, or just freshly boiled water), so when I make my tea, I usually wait around 20 minutes ...
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1answer
33 views
Artificial sun Sculpture [closed]
I am designing a dynamic sculpture of the solar system, about 6,500 feet long from the sun to Neptune. At this scale the sun will be 24 inches in diameter, Earth a quarter of an inch. Every hour the ...
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82 views
Coldest temperatures achievable in DIY enthusiast/hobbyist setting
Assume I, as a physics DIY enthusiast, would like to cool a little piece of material down to coldest possible temperatures, for my own entertainment or my private curiosity/research ambitions. We all ...
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1answer
48 views
Using an electric/magnetic field to cool particles
I was just thinking that temperature and the motion of atoms are connected. Hence, I was wondering why we can’t just use a magnetic or electric field to hold atoms more or less in place, lowering ...
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1answer
54 views
Cooling of compressed air
If we compress air from $p_1=1bar$ with starting temperature $T_1=20°C$, the pipes behind the compressor become usually "very" hot. However, if we start at $T_1=20°C$ and $p_1=10bar$ and we decompress ...
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4answers
338 views
Intuitive explanation why rate of energy transfer depends on difference in energy between two materials?
The temperature of an object will decrease faster if the difference in temperature between the object and it's surroundings is greater.
What is the intuitive explanation for this?
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1answer
50 views
Cooling down room with just a water
As I know, heat capacity of normal air is ~1kJ/kg and heat capacity of water is ~4.1kJ/kg.
I am trying to cool down room (around 6m³) from 30C to 20C just by cold water.
Let's say I have water with ...
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1answer
73 views
Passive dissipator block between two peltier cells seemingly raising overall temperature differential
I am experimenting with stacked Peltier cells trying to build a simple diffusion cloud chamber.
I noticed that when simply stacking two peltier cells the upper side reaches a temperature (around -15 C)...
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2answers
57 views
Calculate the rate of cooling of huge amount of water to room temperature
Is it possible to calculate the rate of cooling of huge amount of water to room temperature given the following parameters:
The surface of water in contact with air
the surface of water in contact ...
0
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1answer
63 views
What was the original statement of Newton's Law of Cooling?
In our courses of differential equations we usually find Newton's Law of Cooling stated and written as
The rate of change of temperature of a body is directly proportional to the difference in ...
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3answers
189 views
Why don't people just put a water sprinkler on their roof for cooling? [closed]
Some air conditioners work with evaporative processes. So I'm not sure why people wouldn't just use a sprinkler that turns on for a minute every hour or half hour or whatever in order to wet the roof. ...
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1answer
73 views
What is the obtainable work from cooling water? [closed]
In Callen's thermostatistics textbook, problem 4.5-14 says
If the temperature of the atmosphere is 5°C on a winter day and if 1 kg of water at 90°C is available, how much work can be obtained as ...
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2answers
48 views
Cooling of objects Thermodynamically unfavourable?
As I've learnt, systems in the Universe always tend to increase their entropy since it provides a larger number of availiable microstates for energy to be distributed and is hence statisticaly ...
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31 views
Can radiators cool down using only back body radiation?
If you could produce a very thin tube, say less than the thickness of a human hair, designed to carry a hot liquid inside, the diameter is small so that the liquid would have a high surface area to ...
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1answer
48 views
Laser beam versus activly cooled armor. Who will win?
I'm interested in space warfare from a hard sci-fi perspective. Usually I ask these kind of questions on Worldbuilding SE, but I felt that this one fits this SE better.
Recently read this post on the ...
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4answers
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Is this cheap “air conditioner” able to cool a room?
My parents bought this "air conditioner", but I am very skeptical that this can cool a room, or even cool anything.
I doubt that it even has a cooling element, I suspect that it is just a fan + ...
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0answers
27 views
Cooling just one mode?
In the context of Brillouin scattering and Stokes/anti-Stokes scattering in a silicon waveguide, a speaker mentioned optical cooling, but apparently only cooling a single "mode" was cooled. I had ...
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63 views
calculate CFM of a ceiling fan
I'm trying to calculate, or even understand what data do i need to calculate the CFM of a ceiling fan. in many countries this is a given data in the product details but not where I'm from. I have the ...
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1answer
47 views
How do we cool gases to the $mK$ range?
When we set new records for coldest temperature in the universe, we usually do it with gases (see: https://physicsworld.com/a/millikelvin-cooling-of-large-molecules-is-no-myth/)
How do we pull this ...
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1answer
826 views
How does an ultrasonic humidifier / atomizer affect temperature?
Evaporative cooling is a technique used to cool air by using the evaporation of a liquid.
My google research on evaporative cooling shows a ubiquitous concept of forcing air through a pad/membrane/...
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3answers
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Does tea made with boiling water cool faster than tea made with boiled (but still hot) water?
I always make tea with boiling water - not water that is almost boiling, not water that has boiled and stopped boiling a few seconds earlier - in my opinion, for the best tea flavour the water must be ...
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1answer
171 views
Cooling effect caused by evaporation
Evaporation is said to cause cooling effect because it absorbs energy from surroundings to change its phase from that of a liquid to gas. I am in doubt as to why would the surroundings be ready to ...
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1answer
53 views
How does evaporator coil absorb heat when a cool liquid is passed inside it?
My question is how does evaporator coil inside a refrigerator cools the inside atmosphere by absorbing heat? I am fully confused, how the heat absorption happens? This technically sounds confusing.
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2answers
4k views
What are some factors affecting the rate of cooling of a liquid?
What are possible factors affecting the rate of cooling of a liquid, aside from the volume of water, surface area of the water, or type of container.
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1answer
353 views
Cause of change of tea volume during cooling
At work I often drink tea, and i usually fill my cup to the brim with boiling water. When I let it cool though, until it's ready to drink, the liquids surface has sunken by about a fingers width.
To ...
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2answers
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New black Van in South Florida - To insulate or Not? Radiative Cooling effect?
I'm not homeless, I'm just frugal and trying to drive a lot less.. maybe I'm adventurous. :) Anyways, I've been working , eating and sleeping out of my new Black van. The van is brutally hot during ...
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218 views
Can cooling airflow be too fast for efficiency?
If using pressurized air flow to cool a hot metal tube (by blowing the air through the tube, not blowing it over the exterior), would high volume fast airflow cool better than low volume slower air ...
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2answers
174 views
Momentum Change from Spontaneous Emission
In page 188 of Christopher Foot's book on atomic physics, he talks about the Doppler cooling limit, and how it comes from a random walk caused by spontaneous emission. He claims that each spontaneous ...
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1answer
311 views
How to develop a model for cooling rate of steel tube in air?
I am trying to develop an equation to determine the cooling rate of a steel tube in air. I'm using Fourier's Law, Stefan-Boltzman Law, Newton's Law as well as the specific heat capacity equation. The ...
