Weather Science and Humidity are Illogical!

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leehljp

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Weather Science and humidity are Illogical!
(That title was written in jest even though it does “seem” to present contradictions when viewed in context of different regions. I know the differences and why, but it is fun to look at the seemingly illogical side - as a fun discussion.) 🙂

Recently in this thread ( https://www.penturners.org/threads/oh-the-joys-of-home-ownership.165830/#post-2082911 ) Sharon Wertz wrote: “An evaporations (evaporative cooler) doesn't work with the dew point above 55 degrees. We rarely get there except during the monsoon. Today our dew point is 22 degrees and it is 74 degrees in the house with 95 outside.

Her post got me to thinking (That is dangerous):
I live in the South and lived for a while in the New Orleans area where 85° - 90° with 100% humidity will make the “Feels Like” temperature to be 105° - 125°, 😲 depending on who is describing it, and that usually is EVERYONE! :oops: 😃

Now the STRANGE thing is this: IN Phoenix, add humidity in the house when it is 95° outside and the temperature drops WAY down (74°). IN New Orleans, add humidity to 85° and you will swear the temperature is NORTH of 110°!

Something just doesn't make sense about that! ;)
 
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randyrls

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The primary cooling mechanism of your body is evaporating sweat from your skin. When relative humidity is high, there is less evaporation of your sweat, so your body feels hotter. I was in Alaska (winter time - north shore near Point Barrow). Our clothes dryers did not have any heating elements in them. They just sucked in cold air from outside (bone dry) and then exhausted the now moisture laden air back outside. In VERY COLD weather, our clothes might freeze before they got dry. We had to go outside and chip the ice away from the dryer exhaust vents every 2 or 3 days.
 

Dehn0045

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AC condenser misting has been around for a long time. The evaporative cooling reduces overall electricity consumption for an AC system (20-30% reduction). The major downside with misting a traditional air cooled condenser is mechanical damage.
 

leehljp

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I am familiar with evaporative cooling from some time is West Texas. Also, I understand the differences of them vs AC and why, but it is just strange to discuss this with those that don't. This came up yesterday in a discussion on AC vs Evap-Coolers and I asked a couple of fellows why - concerning my original post. I got them all confused.

The major downside with misting a traditional air cooled condenser is mechanical damage.
Sam, I learned that the hard way some years ago.
 

Dehn0045

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@leehljp there is a new system out called Mistbox, it only mists when the condenser fan is on and has some water treatment (though I'm not sure how effective the treatment). I was almost enticed into trying it, but alas I decided to eat the higher electric bill but worry less about my condenser crapping out.

Now that I think about your post a little, my thinking was a little off. What you're describing is like the "Cool Zone" tents that they have at fair that have a bunch of misting systems. I'm thinking the problem with the AZ vs LA comparison is that in AZ you recognize (I think) that the actual air temperature (dry bulb) would drop substantially, but in LA the before is 85 and moderate humidity but the after is 85 and high humidity. Of course simply increasing the humidity but keeping the same dry bulb tenperature would make it feel hotter, but even in LA you would see some decrease in temperature if you add humidity to a space with medium humidity.

Maybe I'm way off, but at least I got to do a little mental gymnastics 🤪
 

leehljp

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I'm aging. Couldn't think of the right words, I should have used the word "irony" in it to describe the situation.
 
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All I know is that I cannot stand high humidity! I spent some time in one country where it was 100 degrees and almost 100% humidity without rain! That was unbearable!
 
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I don't know all that much about how the heat and humidity works, not interested enough to find out, but when the weather guessers start telling me it's 95 degrees but feels like 105 degrees I kinda turn off... if it's 95 it feels like 95... I don't know what 105 feels like unless it's 105... just me not scientific....

About the water coolers, that was all the AC we had when I was growing up, actually when I was a teen... earlier years we would just go sit in the shade... my dad never liked the compressor type AC, he would always say, "If I'm hot I'll sit in the shade".... he rarely sat inside under AC, except when there was a baseball game.

I worked in a movie theatre my junior/senior year of HS... we only used a water cooler... the area behind the movie screen was one giant water cooler... we had two huge straw mats that measured about the size of the screen that had water recycling down through them and a 4 or 5 foot fan blowing through them... don't know if the dark theatre also helped, but it would get downright cold in there.
 

sbwertz

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When my evaporative cooler is running, the indoor humidity is usually 50-60 percent. Right now it is 50 percent in my living room. Outdoor temp right now is 110 degrees. Indoor temp is 80 degrees. Outdoor humidity is 5 percent, dew point 24 degrees. My electric bill is $90. With AC it would be running about $300. When the outdoor temp is that hot and dry, 80 feels pretty cool. Add a ceiling fan, and we are perfectly comfortable. At night it gets down near 70 in here (high 80s outside) and I need a light blanket.

Thermal shock is really hard if you are in a building with the temp around 70 degrees and walk out into 110 or higher. Some stores just about freeze me out in the summer. So even when we are running the AC we keep the thermostat set at about 80 degrees.

My dry eyes are very uncomfortable at 5 percent humidity. When I run the AC I also run a humidifier.
 

magpens

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I live in a part of the world where summertime AC is not usually "essential" by any stretch, altho' some have it.

Altho' I really should, I have not even educated myself in the appropriate terminology (relative humidity, dewpoint, "feels like", etc.)

I came across this article yesterday which has a catchy title, and it might be of interest to some so I will give the URL.

I might need to stress that I am not being controversial in any way, just providing access to "information", if that's what it's about.

I should also stress that I haven't a clue about anything related to weather except the conversions between degrees F and degrees C.

So here's the article about AC with the catchy title ....

 
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