Questions tagged [cooling]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1
vote
0answers
16 views

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?
0
votes
2answers
24 views

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 ...
0
votes
0answers
24 views

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 ...
2
votes
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 ...
0
votes
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....
0
votes
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 ...
1
vote
0answers
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
votes
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?
0
votes
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 ...
1
vote
0answers
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 ...
0
votes
0answers
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 ...
7
votes
4answers
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 ...
3
votes
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 ...
1
vote
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
0answers
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
votes
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) ...
0
votes
0answers
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 ...
0
votes
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 ...
1
vote
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 ...
1
vote
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 ...
-1
votes
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 ...
1
vote
0answers
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 ...
0
votes
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 ...
0
votes
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 ...
4
votes
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?
1
vote
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 ...
0
votes
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)...
0
votes
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
votes
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 ...
1
vote
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. ...
1
vote
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 ...
0
votes
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 ...
1
vote
0answers
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 ...
0
votes
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 ...
40
votes
4answers
9k views

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 + ...
1
vote
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 ...
1
vote
0answers
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 ...
0
votes
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 ...
0
votes
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/...
10
votes
3answers
2k views

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 ...
4
votes
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 ...
-1
votes
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.
0
votes
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.
3
votes
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 ...
0
votes
2answers
38 views

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 ...
0
votes
2answers
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 ...
1
vote
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 ...
0
votes
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 ...