humidity

Does humidity affect temp? Give me your opinions.

danson

i would imagine air with a higher water concentration has a higher potential to hold more heat.

just like water cooling vs air cooling.

dew.

so high humidity means higher temps since it holds heat?

no that's not what i said. it has more potential to hold heat.

water hold more heat than air. so water heats up slower and cools down slower, but it can hold more heat energy. air holds less heat energy.

i am having trouble verbalizing this. anybody who actually took physics want to take a shot?

dew.

Ok, you know how the heat index works, right?? Higher humidity in the air makes it feel hotter...so lets pretend it really is hotter...

Heat transfer, out of a radiator or off the fins of a hsf, depends on the initial temperature difference between the surrounding air and the temp of the metal. Higher difference = more heat removed. Now assume the temp of the metal is always the same...and larger then the temp of the outside air. In order to make the difference between the two larger, you would need to DECREASE the temp of the surronding air. So, if our assumption that the more humid air really is hotter stands, then the more humid air will not allow as much heat transfer as dryer (or, using our heat index assumption, cooler) air!!

Does that make sense?? I'm not sure if that's the best way to explain it though...

Humidity will make no difference in an air cooling scenario. The only variable that affects the rate of conduction from the heat sink to air is the temperature differential. i.e. the higher the difference the greater the heat transfer

the rationale behind the heat index is since we remove heat from our bodies by evaporation, a higher humidity will inhibit evaporation due to the saturation of water molecules in the air. it would therefore feel hotter as we lose our ability to cool ourselves. since evaporation isn't a factor in standard water or air cooling rigs, the heat index means nothing.

Tiger said:

Humidity will make no difference in an air cooling scenario. The only variable that affects the rate of conduction from the heat sink to air is the temperature differential. i.e. the higher the difference the greater the heat transfer

Click to expand...

be careful speaking in absolutes........
higher humidity means more water suspended in the air, means more absorbtion of heat off of a heat sink, means a cooler heat sink, means a cooler.......
ever have the ac on in a car and drive through a fog???? instantly the cooling is increased and the ac is colder...same deal only much less pronounced.
wj