Questions tagged [cooling]

205 questions
48
votes
5 answers

Why is Helium so hard to liquify?

By the end of the 19th century all gasses had been liquefied apart from helium (He). What is it about helium that makes it so hard to liquefy compared to the other gases? And why does it need to be pre cooled in the Joule-Kelvin expansion?
44
votes
4 answers

Cooling a satellite

Satellites are isolated systems, the only way for it to transfer body heat to outer space is thermal radiation. There are solar panels, so there is continuous energy flow to inner system. No airflow to transfer the accumulated heat outer space…
40
votes
4 answers

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 + humidifier. But even if this device had a cooling…
40
votes
10 answers

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 has water on the outside of it. a. In terms of…
25
votes
2 answers

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 is brought to the fridge so much more relevant that…
24
votes
1 answer

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 chocolate. It caught my attention that the…
12
votes
3 answers

Why does splitting hot tea from one glass in two glasses makes it cool faster?

For a while now I've noticed that if I take a cup of hot tea and pour it into two cups and leave it then both cups will cool faster than the single cup. How is it that nature cools two cups of tea in parallel more quickly? It's still the same amount…
bodacydo
  • 1,313
11
votes
3 answers

Can the temperature of a body become lower than the temperature of the surrounding air?

In winters, frost is formed on the grass and wood and not on concrete roads.Temperature of frost is lower than the temperature of the surrounding air.So a question arises ""Can a body become colder than the environment"" or there is something which…
10
votes
3 answers

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 boiling as it comes out of the kettle into the…
10
votes
3 answers

Why can't the ocean be frozen by blowing on it?

Early superhero comics often would magnify familiar experiences as the basis for super-powered feats even if completely scientifically flawed. Analogizing insect ability proportionately to humans, alleging gravity differential is sufficient to…
8
votes
4 answers

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 is on and being used under a normal everyday home…
6
votes
2 answers

Considerations and questions for a DIY heat pipe; how to choose a working fluid?

I plan to build a DIY heat pipe! For more info on what a heat pipe is, see Wikipedia. I would like to use it to cool a desktop graphics card I have. I am having trouble deciding how to choose the working fluid for the pipe. I plan to build it based…
KDecker
  • 837
6
votes
4 answers

Will a water-cooled system heat up a room less than an air-cooled system?

Recently - motivated by the recent heat where we live - an acquaintance argued that a water cooled computer will not heat up the room as much as an air cooled computer will. His reasoning was that the processors never reach temperatures as high as…
G. Bach
  • 203
6
votes
2 answers

Does the temperature of water determine how much heat will be removed from air used to evaporate it?

This is a question about evaporative cooling as used in residential evaporative cooling appliances. This type of cooling uses the heat in the ambient outside air to evaporate water and remove the heat from the air, then push the cooled air inside.…
iLikeDirt
  • 205
5
votes
5 answers

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 generate heat in the process of cooling. This is…
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