[Archive!] Pure mathematics, physics, chemistry, etc.: brain-training problems not related to trade in any way - page 54
You are missing trading opportunities:
- Free trading apps
- Over 8,000 signals for copying
- Economic news for exploring financial markets
Registration
Log in
You agree to website policy and terms of use
If you do not have an account, please register
Air conditioning connoisseurs = fridge connoisseurs?
Practical question, at what ambient temperature do modern refrigerators stop freezing?
What do you understand by ambient temperature?
What do you mean by ambient temperature?
The temperature of the room where it is standing....
Let me explain the situation, the gas boiler broke down, let's say in the "country house", the house froze thoroughly in two weeks, everything froze, the frost was decent. One place in the whole house where everything is the opposite - the fridge. Everything has defrosted, dried out, etc. There were no power outages...
It's hard to say. Probably somewhere between -20 and -40°C. If it's a freon cooler, then:
-
1. At very low temperatures, the oil viscosity in the refrigerator compressor increases greatly, and the compressor can no longer rotate its motor, i.e. the refrigerator cannot operate;
2. The Freon condenses at low temperature and is no longer a gas but a liquid, even at normal pressure and the refrigerator will not work under these conditions either;
3. The refrigerator's temperature control relay simply will not turn on the compressor if the temperature inside it (the refrigerator) is very low. This is usually the case - the temperature inside is no higher than outside;
-
This is the system of equations.
It's hard to say. Probably somewhere between -20 and -40°C. If it's a Freon refrigerator, then:
-
1. At very low temperatures, the oil viscosity in the refrigerator compressor increases greatly, and the compressor can no longer turn its motor, i.e. the refrigerator cannot operate;
2. The Freon condenses at low temperature and is no longer a gas but a liquid, even at normal pressure and the refrigerator will not work under these conditions either;
3. The refrigerator's temperature control relay simply will not turn on the compressor if the temperature inside it is very low. This is usually the case - the temperature inside is no higher than the temperature outside;
-
That's the system of equations you get.
Thank you. It's science. The only bad thing is that the fridge threw that out at -5...-7C, hardly any lower... I wonder if it'll freeze when I fix the boiler?)
Temperature of the room where it is standing....
Let me explain the situation, the gas boiler broke down, let's say in the "country house", the house froze thoroughly in two weeks, everything froze, the frost was decent. One place in the whole house where everything is the opposite - the fridge. Everything has defrosted, dried out, etc. There were no power outages...
By the way, note, fridges also don't like overheating (sunlight, proximity to other fridges, cookers, boilers, etc.).
The likelihood of a fridge breaking down in summer is many times greater than in winter.
There's another trick that few people know. Refrigerators are very afraid of undervoltage. If the mains voltage drops
from say 220 to 180 volts, the fridge can easily go out of order. In winter, such a drop is very possible, especially at the cottage.
In winter many people use powerful electric heaters at their dachas.
Thank you. The science is sound. Too bad the fridge threw that out at -5...-7C, hardly any lower... I wonder if it'll freeze when I fix the boiler.)
If the compressor's burnt out, nothing will help. We'll have to replace it. By the way, if you replace the compressor, you'll also have to pay for the freon to fill the fridge, and maybe a new filter for the unit as well.
Mathemat, По поводу комнаты с зеркалами. Посчитал в dialux два варианта.
[...] Как видите, в последнем случае освещённость почти вдвое выше.
I doubt that dialux takes into account the wave nature of light. It probably sees the new sources (which are in mirrors) as independent of the first, true one. But it doesn't really. The decision is not made.
If the light were to increase, you could put one candle in the centre of a huge room and then illuminate the whole room with a system of mirrors.
I doubt that dialux takes into account the wave nature of light. The decision is not made.
If the light were to increase, you could put one candle in the centre of a huge room and then light up the whole room with a system of mirrors.
What does the wave nature of light have to do with it? A mirror absorbs less light energy than, for example, green wallpaper.
Imagine this:
Option 1: The walls of the room are painted white;
Imagine this: A room with black wallpaper;
Which one would make the room brighter? Obviously the first one.
-
That's how you save energy. They hang mirrors on the walls, they do suspended ceilings with mirrored tiles.
white paint the walls, white wallpaper, light parquet, etc.
Именно так экономят электроэнергию. Вешают на стены зеркала, делают подвесные потолки с зеркальной плиткой, красят стены белой краской, наклеивают белые обои, кладут светлый паркет и т.д.
What's in blue is fundamentally different from what you brought up later. The blue highlighting is not for economy, but to create a space effect. The rest, however, is for economy.