Questions tagged [cooling]
The cooling tag has no usage guidance.
125
questions
39
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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
19 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
21 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
35 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
66 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
1k 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
96 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
25 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
376 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
82 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
29 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
38 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
69 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
104 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 ...
0
votes
2answers
75 views
which give higher cooling rate , strong circulated water or thick copper plate? [duplicate]
imagine if I have hot metal piece I want to cool it as fast as possiple, should I put it in strong circulated water bath or just stick it between 2 thick copper plates ?
the calculated heat ...
-1
votes
1answer
26 views
which is more effective chilling for metal casting, thick copper die or water-cooled thin copper mold? [closed]
It is will known that increasing cooling of a metal casting will lead to finer micro-structure which mean higher mechanical properties.
If I have 2 molds one is thick copper die ,& second is just ...
0
votes
2answers
421 views
Effectiveness of cooling oneself by a hand fan
I recently had a discussion with a friend of mine regarding the effectiveness of handheld fans. My friend argued that you would always get warmer. I’m sure that this needn’t be the case, as the system ...
1
vote
0answers
34 views
Cool a room with a fan, what sens orientation? [duplicate]
It is really hot these days, and at night, I try to cool my room before going to sleep but I'm wondering in which sens I should orient my Fan
Answer A : Push the hotter air with my fan outside.
...
-1
votes
1answer
42 views
Name of this type of cooling system?
If you pump around air in a cyclic tube at a high speed, and one part of the tube is narrower than the rest of the tube, the air flow will have to increase in speed when it enters the narrow part in ...
1
vote
3answers
1k views
Why does evaporation cause cooling?
I am aware that the evaporation process causes cooling in the remaining liquid, but why?
If anyone can give me the maths and or equations to prove / show this I would be most appreciative.
-1
votes
1answer
485 views
Newton's law of cooling for negative Kelvin temperatures
Newton's law of cooling says that $$\frac{dT}{dt}=-k(T-T_a)$$where $T$ is the temperature of the substance, $T_a$ is the ambient temperature, and $t$ is the time. Usually, we say that if $T>T_a$, ...
22
votes
1answer
260 views
Melted chocolate forming fractal branches
Tree-like structure in chocolate
Today I let some melted chocolate solidify in a smooth bowl in my fridge. When it had settled, I gently heated the outside of the bowl with warm water to unstick the ...
4
votes
1answer
141 views
Radiation cooling in space [closed]
Would the droplet cooling system from Mass Effect be actually possible in our universe? I'm interested in expanding the space industry and promote manufacturing in space. One of the biggest problems ...
5
votes
5answers
132 views
Is it more difficult to cool than heat?
While it seems there is a lot of ways to generate heat, using mechanical, chemical or electrical engineering solutions, it seems that generating cold is more difficult. Most cooling devices that exist ...
0
votes
2answers
226 views
Heat transfer in the isothermal expansion in the Carnot cycle
Problem
In the Carnot cycle there are two adiabatic and two isothermal processes. This question focuses on the isothermal expansion.
In the isothermal expansion books often writes that the system is ...
0
votes
1answer
216 views
Adiabatic expansion of ideal gas
I am considering a system with initial pressure $P_{A}$ and volume $V_{A}$.
The internal energy $U_{A}$ should be zero. Then I have the following law for an ideal mono atomic gas $P^{3}V^{5}=const$. ...
0
votes
1answer
77 views
How does a heated object raise the air temperature around it?
When object is heated and the heat source is removed, how long does it take to cool down and how it does it change the air temperature around it. If We know the temperature of the heated object and ...
0
votes
1answer
96 views
Refrigerant vs water heatpipe [closed]
For a heatpipe that is connected to a 50 Celsius object on one side,and a heatsink at 23 Celsius air at other side, what fluid filling will give better heat conductivity? Plain water, or some kind of ...
0
votes
1answer
701 views
What is Excess Temperature?
I am reading about Newton's Law of Cooling and the following is an extract from my textbook on the experimental verification of this law.
"Consider a spherical calorimeter of mass m whose outer
...
2
votes
1answer
106 views
Why must Debye cooling eventually slow down?
Masanes and Oppenheim derive a maximal cooling rate $T(t)\geq k/t^7$ in their paper on the third law of thermodynamics. This is not just a bound on passive cooling, but also active cooling using any ...
0
votes
2answers
139 views
Can I increase cooling efficiency with evaporative cooling?
I had an idea recently. But I don't have the physics knowledge to know if it makes sense or not. I've become a bit of a PC enthusiast lately and one thing that is big in the PC world lately is water ...
0
votes
0answers
85 views
What is the radiative cooling rate at extremely cold temperatures?
Consider a spherical object in empty space, in the far future where the CMB can be entirely neglected. What is the cooling rate as it approaches radiative equilibrium?
Here is what I got so far:
The ...
0
votes
1answer
132 views
How does the power consumption and cooling capacity of a Peltier refrigerator change when the interior is made reflective?
I've a small Peltier cooler which I used to store some chemical stuffs. So, I recently modded the design to make it more bigger and improve its cooling + insulation.
I've added an aluminium piece ...
-4
votes
1answer
307 views
Analyzing the rates of cooling points using the graph and data [closed]
how should i use this data to analyse the differences between the two materials. and what calculations could i use for it?
0
votes
1answer
60 views
Cooling a bottle to around -70°C the easy way
As the topic already tells, I want to cool a glass or aluminium bottle down to roughly -60 to -70 °C for the sake of science. Additionally this setup should be portable for showcasing it at school.
I ...
-1
votes
1answer
379 views
Time of death from Newton’s law of cooling – do I need the initial temperature? [closed]
Suppose that a corpse was discovered in a room and its temperature was 32°C at 12pm. The temperature of the room is kept constant at 20°C. Three hours later the temperature of the corpse dropped to 27°...
24
votes
2answers
3k views
Is frequent opening of the fridge really so significant for the power consumption?
I've read several popular articles telling that frequent opening of the fridge highly increases the power consumption.
Is it really so significant? Isn't the heat in the room-temperature food which ...
1
vote
1answer
577 views
What is the role of the plug in Joule-Thomson expansion?
I've read a lot on J-T effect but it isn't still very clear...
What is the role of the plug or valve ? It seems to me a very strange "non physical" requirement... It is often said that because of the ...
0
votes
3answers
250 views
Air cooling by forcing air through soda bottles
I saw this story on YouTube about a guy who made a panel of empty soda bottles to cool wind as it blew through them: https://www.youtube.com/watch?v=i2NWr6bRKWU
I tried this with a box, filling it ...
2
votes
1answer
99 views
How does the Newton Law of Cooling should be modified in case of free convection?
According to "Mathematical Modeling: a Differential Equations approach" by Barnes and Fulford 2nd edition, it should be
$ T' = k (T-T_0)^{5/4} $
where $T_0$ is the temperature of external gas or ...
1
vote
1answer
2k views
How do the pressurizers in a PWR nuclear reactor (Pressurized water reactor) work?
I did a bit of googling and wikipedia informed me that the pressurizer is just a vertical tank of sitting coolant water that directly connects to the reactor. Then electrical heaters in this vessel ...
0
votes
0answers
28 views
Gas energy dissipation causing collapse
Why is the dissipation of energy of gas causing it to undergo gravitational collapse? Is this a result of the virial theorem? Reduced pressure gradient?
0
votes
2answers
168 views
generate electricity from cooling tower
I am wondering while there is a reasonable continuous air flow inside the cooling towers from down upward due to the pressure difference between down and up, why we don't use a wind turbine and placed ...
0
votes
1answer
47 views
Does condensation on a cooling element indicate lost cooling efficiency?
I have a box with 80%ish humidity, temp ~80f, a strong fan, and a TEC (peltier) with coolsink mounted-- the coolsink does NOT have a fan attached.
The TEC is ~68' normally and drips condensation from ...
2
votes
1answer
443 views
Newton's law of cooling
I learned in physics class that, according to Newton's Law of Cooling,
"The rate of fall of temperature of a body is directly proportional to the excess of temperature over the surroundings, ...
40
votes
10answers
8k views
Condensation of Water. Classroom Controversy
In our test there was a question that went like so:
Question 4 You have a glass of iced water on an unshaded picnic table and went for a walk for 30 minutes. When you return you noticed
the glass ...
0
votes
1answer
198 views
Does Newton's law of cooling work for forced convection?
Does Newton's law of cooling work for forced convection, what extra parameters do I have to consider in the law then?
0
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1answer
150 views
Q: Laser cooled hydrogen
Is it possible to cool down hydrogen some much (using lasers) to get a metalic form of the element? Or to try to produce it no such cooling is required?
-1
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2answers
69 views
Self sustained cooling approach [closed]
I have a hot object (about 200 centigrade), and would like to cool it down. Is there a way to use its heat to operate a cooling system without exerting external energy; as heat is energy and can ...
0
votes
1answer
1k views
Venturi effect better for cooling through duct
I have a laptop which is overheating, and I would like to improve the cooling (without opening the laptop).
The only option I can see (reasonably) is to increase the airflow moving through the laptop....
