except the other guy's mention of Death Valley being very dry and very hot shows you're wrong. Auto AC is for removal of heat from the interior,moisture removal is secondary.
Cooler than with the windows closed, yes.[/QUOTE] but not comfortable. and not much cooler. sweating heavily in the 100plus -dry- desert heat still does not make a person comfortable. But the cool air of AC removes that heat and allows comfort. Yes,it is. AC is primarily a HEAT transfer device. It's not specifically designed to remove humidity,but to remove HEAT.
Yes,it is.[/QUOTE] OK, fine. Consider this the next time it's a nice, cool, 63 degrees outside--and 100% relative humidity. And ask yourself why the hell you are dying to turn on the A/C.
so.....you have an air conditioner in your car and/or home that's full of hygroscopic materials? My question to jim was, in the context of this conversation, how are you removing moisture without condensing it onto a cooler surface?
you could do it with pressure changes - moisture condensation is always a problem in paint shops and there's no significant temp change in air lines there - unlike a/c systems. i appreciate that you think dehumidification is a great thing, and maybe it is a side-benefit of having a/c, but the objective of the equipment is not to simply dehumidify. if it were, it wouldn't go to the trouble and expense of venting waste heat to the outside of the vehicle, it would be used to re-heat the dehumidified air inside the car and thus save on componentry and energy.
OK, fine. Consider this the next time it's a nice, cool, 63 degrees outside--and 100% relative humidity.[/QUOTE] Consider Death Valley;100 plus heat and DRY air. Yet you still need to remove the HEAT from your auto to be comfortable,rather than just use the fan to pull in dry outside air that's around 120 degF. To repeat,AC is a HEAT transfer device,and you have to remove the interior heat to be comfortable. few people use their auto AC in such temps. such a use is SECONDARY to the primary purpose of -removing HEAT- from an auto interior. I live in central FLORIDA,and I know all about humidity,and about hot cars.
Seriously? Ok. By *heating it*.[/QUOTE] In the context of this conversation? Seriously? But I thought you wanted COOL air. And you don't remove moisture by heating. You change the dew point, but you don't remove moisture. Condensation removes moisture.
"Few People" Man you need to get out more. Using the A/C in the winter months when there is snow and ice clears the windows of condensation so quickly. Removing the humidity is part of removing the heat from a vehicle or building.
In the context of this conversation? Seriously?[/QUOTE] no, he's confused. correct. but it's also correct that hotter air can hold more moisture. that doesn't make it "dry", but the proportion relative to saturation decreases. correct.
It's a lot better than just relying on a dehumidifier to remove moisture from a building. The heat that the dehumidifier generates while removing the moisture builds up rapidly. Better to vent the heat outside too.
auto operators manuals all tell owners to use the AC periodically in winter months so it gets lubricated and doesn't rust up.If they have to tell owners that,then frequent use in winter is not common. It used to be that most cars sold up North didn't have AC,unless ordered as an option.(and they were hard to sell down south without AC) Since foreign carmakers began bundling it as standard,that's changed,I believe. BTW,I grew up in Buffalo and lived in the North for many years. a -secondary- part.Not the primary purpose of auto AC. note there is a temperature control on every auto AC,but no humidity control.
In the context of this conversation? Seriously? But I thought you wanted COOL air.[/QUOTE] You didn't ask "in the context of this conversation." Stop digging that hole and give up, man. (...)
You didn't ask "in the context of this conversation." Stop digging that hole and give up, man.[/QUOTE] You're stretching. YOU knew what the context was, and chose to ignore it for your own purposes. "Conversational implicature"--first look up what the words mean, then look up what the phrase means.
Incorrect. Expansion of compressed gases is what causes the cooling effect. The removal of moisture is a side effect. One can dehumidfy one's car without cooling it. I frequently have the compressor on during the winter to dry out the air, even though I'm also running the heater. Says someone in Nova Scotia. -- - dillon I am not invalid "Gee, Jimmy,I'm sorry to hear that your girlfriend turned out to be a Cylon." -Special Agent Tim McGee, "NCIS"
while that effect exists, it's small beer compared to the real heat exchange mechanism - that of changing phase from liquid to gas. it's liquid /evaporation/ that causes the cooling effect.
Not for the human body. you can fart all you want and it's not going to cool you one bit. ;-) AIUI,Elmo was claiming that a -person- is cooled more by the lowering of humidity than by the cool air itself.He said the -primary reason- for auto AC is to lower interior humidity,that the cold air is just a means of doing that. Of course,the example of dry hot desert air disproves that. The body also radiates away heat by other means than perspiration,and if the body is not absorbing heat from the environment(being cooled by cold air),it can radiate more heat away.(by all means)
radiation is not our primary means of heat dispersal. especially not at ambient above 98.4F. the phase change of water evaporation otoh, that of sweating, dumps heat spectacularly well.
