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The emergence of heat and humidity too severe for human tolerance (2020)

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Re: The emergence of heat and humidity too severe for human tolerance (2020)

#341

Post by f154hfds »

lmilcin wrote: post #234
Aeolun wrote: post #227

Earlier quoted context omitted.

> going into cellar. The air will get cooler but the humidity will rise. If we are already counting on a wet bulb temperature of 35C, the humidity is likely already very close to 100%. Reducing the temperature is likely to be a net good.

That's false. TLDR: The air gets cooler but still can't cool you. Your body produces heat that has nowhere to go and you still die. Then the walls of the cellar heat up immediately, because cooling 100% humid air requires sinking a lot of energy. If you found yourself in conditions of an actual heat wave as described, you would despair at the fact the air can get cooler in your cellar but it doesn't cool you at all.…

This is all fascinating stuff to me, I'd never really heard of wet bulb before. Quick question though: how does the pressure difference play into this in a basement? As far as I'm aware below ground pressure and voids under basements tend to cause pressure differentials in even non-AC basements (causing radon issues where I'm from)? I assume this would help a cellar situation in the event of power outage as air even slightly below ground tends to be much cooler than above ground air?

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#343

Post by lmilcin »

bumby wrote: post #323
lmilcin wrote: post #188

Earlier quoted context omitted.

Yes, this is completely correct. I would add the wet bulb thermometer needs large evaporation area (so the sock cannot be too wet and definitely you can't put it in the bucket) and/or some airflow around it. Otherwise it will show some temperature between actual dry bulb and wet bulb temperatures. In practice, nobody seriously uses wet bulb thermometers outside of school experiments because they are such a PITA. It i…

> nobody seriously uses wet bulb thermometers outside of school experiments because they are such a PITA. It is easier to just measure dry bulb temperature and humidity How is humidity typically measured? I was under the assumption a hygrometer uses both dry and wet bulb measurements.

Wet bulb requires it to be... you know... wet.

Not very practical to include in your electronics.

I don't know exact method used but I can assure you, there is no water reservoir in any of my gadgets:)

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#344

Post by zabatuvajdka »

14 wrote: post #146
fencepost wrote: post #77

Earlier quoted context omitted.

On a purely technical basis that may seem reasonable. On a "we're talking about human beings here" basis what do you do about all the people who feel that the selection and admission process was corrupt and that they've been robbed of their chance at safety? Do you expect them to meekly acquiesce?

I imagine once the first big wave where a nation hits the wetbulb temperature and there is a mass die off you will see panic in surrounding nations and they will scramble to a border. What will nations do with millions of people knocking at the fence wanting in? Uncertain times for sure.

It’s going to be a global scale “north versus south” war like in South Park—everyone will blame Canada… and Satan will… err never mind. :)

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#345

Post by echlebek »

reddog wrote: post #342

Call me Mr Glass Half Full, but since cold kills 20x more people than heat shouldn't we look forward to a future where many more people survive temperature extremes? https://www.sciencedaily.com/releases/2015/05/150520193831.h...

No! Not even a little bit. Do you realize the rapidity of these changes puts our entire species at risk?

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#346

Post by lmilcin »

f154hfds wrote: post #341
lmilcin wrote: post #234

Earlier quoted context omitted.

That's false. TLDR: The air gets cooler but still can't cool you. Your body produces heat that has nowhere to go and you still die. Then the walls of the cellar heat up immediately, because cooling 100% humid air requires sinking a lot of energy. If you found yourself in conditions of an actual heat wave as described, you would despair at the fact the air can get cooler in your cellar but it doesn't cool you at all.…

This is all fascinating stuff to me, I'd never really heard of wet bulb before. Quick question though: how does the pressure difference play into this in a basement? As far as I'm aware below ground pressure and voids under basements tend to cause pressure differentials in even non-AC basements (causing radon issues where I'm from)? I assume this would help a cellar situation in the event of power outage as air even…

The pressure difference between your backyard and your basement is for all practical purposes null. It is also orders of magnitude smaller than those caused by gusts of wind and changing weather.

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#347

Post by swiley »

zabatuvajdka wrote: post #344
14 wrote: post #146

Earlier quoted context omitted.

I imagine once the first big wave where a nation hits the wetbulb temperature and there is a mass die off you will see panic in surrounding nations and they will scramble to a border. What will nations do with millions of people knocking at the fence wanting in? Uncertain times for sure.

It’s going to be a global scale “north versus south” war like in South Park—everyone will blame Canada… and Satan will… err never mind. :)

I'm always a little surprised the islands in the Canadian archipelago never seem to be sold.

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#348

Post by bumby »

lmilcin wrote: post #343
bumby wrote: post #323

Earlier quoted context omitted.

> nobody seriously uses wet bulb thermometers outside of school experiments because they are such a PITA. It is easier to just measure dry bulb temperature and humidity How is humidity typically measured? I was under the assumption a hygrometer uses both dry and wet bulb measurements.

Wet bulb requires it to be... you know... wet. Not very practical to include in your electronics. I don't know exact method used but I can assure you, there is no water reservoir in any of my gadgets:)

It looks like I’m confusing a classic psychrometer with more modern ones. The modern ones still use absorption of water to change some physical property like capacitance or resistance but this is also why they need to be continually calibrated against a true dry/wet bulb hygrometer.

My experience is that they tend to get out of cal quite often which can lead to bad scenarios, like if using enthalpy setback for air-handling

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#349

Post by The5thElephant »

hh3k0 wrote: post #231
concordDance wrote: post #170

Earlier quoted context omitted.

My money is on space sunshades. While it would cost tens of trillions to make a sunshade by launching from Earth, making sunshades and launching them from the moon should be viable thanks to the lack of atmosphere and low gravity. Assuming that a few million tons of mass is enough to set up a space sunshade manufacturing station (and railgun launch rails) it should only cost a few trillion dollars, cheaper than reduc…

Stratospheric aerosol injection is cheaper and we've got plenty of data for that, as it mimics how volcanic eruptions cool the earth.

Aerosols are far harder to control and to predict harmful secondary/tertiary effects than simply reducing amount of sunlight in a particular area.

Re: The emergence of heat and humidity too severe for human tolerance (2020)

#350

Post by 6510 »

Its funny how many people inflate their importance and think their occupation makes the world go round. In reality it takes a lot of people to keep everything in working order. Specially low wage labor is of disproportional importance. Work done by people who are often (or by definition) financially fragile. A good number of these (and slightly above) involve manual work in already harsh (if not hot) environment. When things get unbearable these people will look at their cards, fold and run away leaving hard to predict holes in the economy.
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