Draconian vacation policies for US slave workers
in [Europe]
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From: Keith W on 24 Jul 2006 15:15 "Mxsmanic" <mxsmanic(a)gmail.com> wrote in message news:f03ac21l4rvj73fddtd7cr86gqh99dpsuh(a)4ax.com... > nobody writes: > >> Evaporation of sweat is excatly what keeps your body cool. > > It's also exactly what increases humidity in the room. The more sweat > that evaporates from your body, the higher the humidity gets, and the > harder it is to keep cool through evaporation of sweat (because it > evaporates more and more slowly as room humidity increases). So you sit and sweat in an room with no ventilation ! It must be NASTY in there by now This > creates a vicious circle of ever-increasing sweat and discomfort, > until the room humidity reaches 100%, at which point no amount of > sweating will provide any cooling at all, no matter how powerful the > fan. Heat exhaustion or heatstroke will often be a risk before this > point is reached, however. > >> And unless you are in an enclosed, air tight car, the amount of water >> you release into the air will just flow out of the room due to the fan >> pushing it out. > > Typically fans are positioned such that they just move air around in a > closed room. There may be little or no connection to the outside > world, and certainly not enough to effectively exhaust humid air. > Psst windows can be opened, take a class. Keith
From: TOliver on 24 Jul 2006 15:35 "Mxsmanic" <mxsmanic(a)gmail.com> wrote... > nobody writes: > >> Evaporation of sweat is excatly what keeps your body cool. > > It's also exactly what increases humidity in the room. The more sweat > that evaporates from your body, the higher the humidity gets, and the > harder it is to keep cool through evaporation of sweat (because it > evaporates more and more slowly as room humidity increases). This > creates a vicious circle of ever-increasing sweat and discomfort, > until the room humidity reaches 100%, at which point no amount of > sweating will provide any cooling at all, no matter how powerful the > fan. Heat exhaustion or heatstroke will often be a risk before this > point is reached, however. Other than in a carefully designed laboaratory environment, constructing a room that "airtight" would be virtually impossible. In "real" circumstances, moisture movement into surrounding air occurs at about the same rate as heat transfer. Obviousluy, a vast advantage of mechanical AC is that the systems removes vast amounts of moisture as it chills the air, dumping the condensate "overboard" at a high rate. Actually, the optimal accomplishment of AC is dehumidification. Survival in high temps involves a combination of efforts, staying out of direct sunlight in which body temp rises due to radiant absorption, drinking plenty of fluids to enourage sweating, and taking advantage of any breeze, mechanical (fan) or natural to increase surface evaporation which acts to cool the skin. You're humidifying the air at a far greater rate through breathing (exhaling moisture) than by skin evapaoration when the humidity is already high, so under most heat conditions given eqial indoor and outdoor temperatures (or higher indoor temps, under a black roof for instance), you're better off getting the Hell outside (but in the shade). Loose, light colored clothing which covers as much exposed skin as possible also helps, and can amplify the cooling of evaporation. Get outside and under a shad tree but with maximum exposure to any breeze. > >> And unless you are in an enclosed, air tight car, the amount of water >> you release into the air will just flow out of the room due to the fan >> pushing it out. > > Typically fans are positioned such that they just move air around in a > closed room. There may be little or no connection to the outside > world, and certainly not enough to effectively exhaust humid air. > In a non-AC auto with the venting system opening and operating and a speed of 30mph or so, total air exchange occurs in a meter of one or two minutes, however, but stop the car and air exchange drops to minimal, while sunlight heats the car rapidly and small children and the elderly can suffer rapid loss of body fluids and go into shock (along with increased body temps). There's more than enough moisture movement and air movement created by simply opening a window. In multi story buildings, opening a ground floor door and a roof door can vastly improve conditions, creating a chimney of rapidly circulating air as hot air rises.... Those of us who grew up in areas with frequent summer temps of over 100F and humdity well above 50% before the "spread" of AC remain pretty conscious of fighting the heat, even now with AC prevalent. Comparing temps....Move the thermometer 20 degrees (F) above normal body temperature and most folks wouldn't last an hour. Move it 40 degrees below and a light jacket maintains comfort. Where I live, were I asked to give up heating or AC, the choice would be easy. Most nights, the day's sunlight means that even a cold night (20F) will not drop the interior temperature in my home below 55F, just at the cusp of good sleeping. The problem in Paris is a population much of which is little acclimated to high temps, unequipped with clothing or ventilation to function in them. and if elderly particularly subject to heat. TMO TMO
From: Mxsmanic on 24 Jul 2006 15:56 Keith W writes: > So you sit and sweat in an room with no ventilation ! Without air conditioning, you sit and sweat in a room with or without ventilation. > Psst windows can be opened, take a class. Opening windows and getting air to move through them are two different things. -- Transpose mxsmanic and gmail to reach me by e-mail.
From: Mxsmanic on 24 Jul 2006 15:57 Dave Frightens Me writes: > I would say most would open a window or leave the room long before > that happened. Opening a window may not be sufficient, and leaving the room may not be an option. > Typically? Typically one opens the window if you are using a fan. Just opening a window doesn't necessarily accomplish anything. Proper ventilation requires more careful planning than that. And if it's hot and humid, opening a window really accomplishes nothing at all. -- Transpose mxsmanic and gmail to reach me by e-mail.
From: Mxsmanic on 24 Jul 2006 16:07
TOliver writes: > Other than in a carefully designed laboaratory environment, constructing a > room that "airtight" would be virtually impossible. It doesn't have to be airtight; in fact, it doesn't even have to be windowless. All it needs is poor ventilation, which is easy to come by, unfortunately. > In "real" > circumstances, moisture movement into surrounding air occurs at about the > same rate as heat transfer. That is to say, barely at all, in many cases. > Obviousluy, a vast advantage of mechanical AC > is that the systems removes vast amounts of moisture as it chills the air, > dumping the condensate "overboard" at a high rate. Actually, the optimal > accomplishment of AC is dehumidification. Yes. > Survival in high temps involves a combination of efforts, staying out of > direct sunlight in which body temp rises due to radiant absorption, drinking > plenty of fluids to enourage sweating, and taking advantage of any breeze, > mechanical (fan) or natural to increase surface evaporation which acts to > cool the skin. Sometimes that's not enough. In humid climates, no fan can blow hard or fast enough to provide adequate evaporative cooling. In general, if you notice any sweat at all on your skin, it is not being evaporated fast enough to keep you cool. It builds up because your body is trying to produce more sweat in order to improve evaporative cooling, but the fact that it collects rather than evaporates makes it clear that the needed cooling is not occurring. Sensible sweating is thus an indication that environmental conditions of heat and humidity are high enough to present a health hazard. > You're humidifying the air at a far greater rate through breathing (exhaling > moisture) than by skin evapaoration when the humidity is already high ... No. In high humidity, you can lose litres per hour in evaporating sweat, many times more than you lose through respiration. > ... so > under most heat conditions given eqial indoor and outdoor temperatures (or > higher indoor temps, under a black roof for instance), you're better off > getting the Hell outside (but in the shade). You're better off finding lower humidity, lower temperature, and better air movement, without direct sunlight. Unfortunately, sometimes these are not available, which is why air conditioning exists. > Get outside and under a shad tree but with maximum exposure to any breeze. What do you tell your manager in the office? > In a non-AC auto with the venting system opening and operating and a speed > of 30mph or so, total air exchange occurs in a meter of one or two minutes, > however, but stop the car and air exchange drops to minimal, while sunlight > heats the car rapidly and small children and the elderly can suffer rapid > loss of body fluids and go into shock (along with increased body temps). Apartments are not automobiles. Changing the air in an apartment at that rate practically requires a tornado (but Europe is starting to get those, too). > In multi story buildings, opening a ground floor > door and a roof door can vastly improve conditions, creating a chimney of > rapidly circulating air as hot air rises.... Only if there's a connection between the two. Modern, large buildings only became practical with the invention of air conditioning. > Comparing temps....Move the thermometer 20 degrees (F) above normal body > temperature and most folks wouldn't last an hour. That would be 118 F. An hour is probably an exaggeration, but many would succumb within a few hours. > Move it 40 degrees below and a light jacket maintains comfort. Yes. I have some light thermalwear that will keep me warm even at temperatures of 15-20 F. > Where I live, were I asked to give up heating or AC, the choice would > be easy. Same here. There are many ways to trap and retain heat; there are no ways to remove heat without active refrigeration of some kind. I can survive longer with no heat than with no cooling. > Most nights, the day's sunlight > means that even a cold night (20F) will not drop the interior temperature in > my home below 55F, just at the cusp of good sleeping. The central heating in my building is so powerful that I often must open windows or even turn on the A/C in winter to keep the apartment cool. The heating really only matches the cold at temperatures below freezing, and those are quite rare today. > The problem in Paris is a population much of which is little acclimated to > high temps, unequipped with clothing or ventilation to function in them. and > if elderly particularly subject to heat. And a population that is massively ignorant of how to deal with heat. But ultimately it boils down to air conditioning. -- Transpose mxsmanic and gmail to reach me by e-mail. |