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Ought I add salt to water bottles, if I'm putting the bottles in front of a fan to improvise an air conditioner?
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Mohamad Bawa
Ought I add salt to water bottles, if I'm putting the bottles in front of a fan to improvise an air conditioner?
It makes sense physically, but the question is if you would have enough bottles for that for sufficient effect.
Twice water heat capacity than ice about compensate lower amount of water, so it can be considered about the same.
The major effect is increased heat transfer keeping it colder for most of the time, as melting, absorbing the most of heat, would occur at lower temperature. Also, liquid provides better heat transfer due convection.
The strongest effect would be using as much salt for solution to still get frozen in the freezer.
About 330 g / 1 L water makes solution with freezing point near $\pu{-20^{\circ}C}$.
50 g / 1.5L PET would be like $\pu{-2^{\circ}C}$.
If we take the heat for ice melting as 100%, water warming up by $\pu{12^{\circ}C}$ takes 15% and ice warming up by $\pu{16^{\circ}C}$ takes just 10%. Shifting melting point by $\pu{2^{\circ}C}$ causes increasing total water heat capacity by 1.25%.
It makes sense physically, but the question is if you would have enough bottles for that for sufficient effect.
Twice water heat capacity than ice about compensate lower amount of water, so it can be considered about the same.
The major effect is increased heat transfer keeping it colder for most of the time, as melting, absorbing the most of heat, would occur at lower temperature. Also, liquid provides better heat transfer due convection.
The strongest effect would be using as much salt for solution to still get frozen in the freezer.
About 330 g / 1 L water makes solution with freezing point near $\pu{-20^{\circ}C}$. 50 g / 1.5L PET would be like $\pu{-2^{\circ}C}$.
If we take the heat for ice melting as 100%, water warming up by $\pu{12^{\circ}C}$ takes 15% and ice warming up by $\pu{16^{\circ}C}$ takes just 10%. Shifting melting point by $\pu{2^{\circ}C}$ causes increasing total water heat capacity by 1.25%.
It makes sense physically, but the question is if you would have enough bottles for that for sufficient effect.
Twice water heat capacity than ice about compensate lower amount of water, so it can be considered about the same.
The major effect is increased heat transfer keeping it colder for most of the time, as melting, absorbing the most of heat, would occur at lower temperature. Also, liquid provides better heat transfer due convection.
The strongest effect would be using as much salt for solution to still get frozen in the freezer.
About 330 g / 1 L water makes solution with freezing point near $\pu{-20^{\circ}C}$.
50 g / 1.5L PET would be like $\pu{-2^{\circ}C}$.
If we take the heat for ice melting as 100%, water warming up by $\pu{12^{\circ}C}$ takes 15% and ice warming up by $\pu{16^{\circ}C}$ takes just 10%. Shifting melting point by $\pu{2^{\circ}C}$ causes increasing total water heat capacity by 1.25%.
It makes sense physically, but the question is if you would have enough bottles for that for sufficient effect.
Twice water heat capacity than ice about compensate lower amount of water, so it can be considered about the same.
The major effect is increased heat transfer keeping it colder for most of the time, as melting, absorbing the most of heat, would occur at lower temperature. Also, liquid provides better heat transfer due convection.
The strongest effect would be using as much salt for solution to still get frozen in the freezer.
About 330 g / 1 L water makes solution with freezing point near $\pu{-20^{\circ}C}$.
50 g / 1.5L PET would be like $\pu{-2^{\circ}C}$.
If we take the heat for ice melting as 100%, water warming up by $\pu{12^{\circ}C}$ takes 15% and ice warming up by $\pu{16^{\circ}C}$ takes just 10%. Shifting melting point by $\pu{2^{\circ}C}$ causes increasing total water heat capacity by 1.25%.
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