- #1
SentinelAeon
- 31
- 3
I have a few questions about how fridge and AC work, i didn't know where to open this thread, i hope this is ok.
So from what i learned so far, both work in a similar way, effectively moving heat from place #1 to place #2, in effect, "cooling" #1 and heating #2. The main difference (apart from their use) is the moving capacity. My fridge is using about 250W when it is turned on. A home AC can use 2000W. So a few things i am wondering are:
1) Since they move heat, their "cooling" effect is actualy more than the amount of electricity they use. I know this is not a correct way to measure it but i always use Watts because it's easy to compare. 400W cooling effect means that if you put 400W cooling effect near a 400W heating element, they will effectively negate eachother. So is it correct that a fridge and AC, while using X amount of power to run the compressor, it is actualy moving 3-4X the energy ? So if an AC is using 2000W while running, it will actualy be "cooling" the place by 6000-8000W ?
2) How do their efficiency compare if you take the average unit ? For instance, for an experiment let's say you have both AC and a fridge and you make 10 kilograms of ice in a fridge, put it in a room and watch how temperature changes. Then the next day, you use AC to have the same cooling effect that you had with ice. Let's say 10 kilograms gave you X amount of "cooling" Watts and AC gave you the same. If then you checked how much electricity was used 1 way and the other, how would they compare ? Obviously it would take a long time to make 10 kilograms of ice and you would get negligible amount of cooling, i wrote 10 kilograms just as an example. How do this 2 devices compare in efficiency, apart from already said much larger moving capacity and purpose.
3) Is it true that if radiator snake behind the fridge is able to dissipate heat better/faster, the fridge will need less cycles to cool the interior to a set temperature and the "turned on" status of fridge will be shorter ? When the gas is compressed, it heats up. It goes into radiator snake to cool down. The colder the gas is, the more capacity it will have to draw heat from fridge/freezer. Now i know that most heat is actualy transfered through liquid changing into gas but surely temperature of said gas has some small effect also ? In a fridge manual it is said that you must not cover the radiator behind the fridge in order for it to be able to dissipate heat.
4) This is actualy a bonus question. Often i will put something out of the fridge for ice to melt before i can use it. I noticed that frozen material, exposed to room temperature will result in condense appearing on the object - room temperature air is rapidly cooled down therefor its relative humidity will rise until the air can no longer hold the water and it will appear on the object. I compared a few different setups trying to figure out what makes more condense and what makes less of it. I tried different materials, they all held 1 kg of ice. I was interested in how glass/plastic/metal container will affect the amount of water that will condense, also was interested in how smooth and textured surface compared. If anyone could point me in the right direction to get more information, for instance, how important is the temperature of ice, amount of ice, surface material and finish.
This is all for now, i think for those more keen in physics than me it will be really easy to answer and a chance for me to learn some basics i have been wondering about :)
So from what i learned so far, both work in a similar way, effectively moving heat from place #1 to place #2, in effect, "cooling" #1 and heating #2. The main difference (apart from their use) is the moving capacity. My fridge is using about 250W when it is turned on. A home AC can use 2000W. So a few things i am wondering are:
1) Since they move heat, their "cooling" effect is actualy more than the amount of electricity they use. I know this is not a correct way to measure it but i always use Watts because it's easy to compare. 400W cooling effect means that if you put 400W cooling effect near a 400W heating element, they will effectively negate eachother. So is it correct that a fridge and AC, while using X amount of power to run the compressor, it is actualy moving 3-4X the energy ? So if an AC is using 2000W while running, it will actualy be "cooling" the place by 6000-8000W ?
2) How do their efficiency compare if you take the average unit ? For instance, for an experiment let's say you have both AC and a fridge and you make 10 kilograms of ice in a fridge, put it in a room and watch how temperature changes. Then the next day, you use AC to have the same cooling effect that you had with ice. Let's say 10 kilograms gave you X amount of "cooling" Watts and AC gave you the same. If then you checked how much electricity was used 1 way and the other, how would they compare ? Obviously it would take a long time to make 10 kilograms of ice and you would get negligible amount of cooling, i wrote 10 kilograms just as an example. How do this 2 devices compare in efficiency, apart from already said much larger moving capacity and purpose.
3) Is it true that if radiator snake behind the fridge is able to dissipate heat better/faster, the fridge will need less cycles to cool the interior to a set temperature and the "turned on" status of fridge will be shorter ? When the gas is compressed, it heats up. It goes into radiator snake to cool down. The colder the gas is, the more capacity it will have to draw heat from fridge/freezer. Now i know that most heat is actualy transfered through liquid changing into gas but surely temperature of said gas has some small effect also ? In a fridge manual it is said that you must not cover the radiator behind the fridge in order for it to be able to dissipate heat.
4) This is actualy a bonus question. Often i will put something out of the fridge for ice to melt before i can use it. I noticed that frozen material, exposed to room temperature will result in condense appearing on the object - room temperature air is rapidly cooled down therefor its relative humidity will rise until the air can no longer hold the water and it will appear on the object. I compared a few different setups trying to figure out what makes more condense and what makes less of it. I tried different materials, they all held 1 kg of ice. I was interested in how glass/plastic/metal container will affect the amount of water that will condense, also was interested in how smooth and textured surface compared. If anyone could point me in the right direction to get more information, for instance, how important is the temperature of ice, amount of ice, surface material and finish.
This is all for now, i think for those more keen in physics than me it will be really easy to answer and a chance for me to learn some basics i have been wondering about :)