31 ms·

The far-reaching effects of air conditioning

216 points by unsupported 9y ago

jaseemabid 9y ago
Unless you have lived in the tropical humid heat, you wont be able to relate to this. Moving to NYC recently and living without an AC or even a fan feels so glorious. I bet 10% of my brain was constantly fighting the heat back when I was in south of India.
- hobo_mark 9y ago
  Likewise, I just came back from HK and I have no idea how they could get anything done there before the introduction of AC. And I was told it gets even worse in the middle of summer!
  - SeoxyS 9y ago
    I went to HK in the middle of hottest times (Aug 1st) last year and it was absolutely brutal. But then again, the entire city really grew out of nowhere during the past century, so it kind of grew in tandem with air conditioning. HK is one of those places that's absolutely amazing as a city, and has some of the worst weather on earth (crazy humidity all the time, insane heat in summer, crazy rains and typhoons all the time… and a cloud of pollution emanating down from Shenzhen).
    - Hydraulix989 9y ago
      I really liked the weather there when I went in December.
      - SeoxyS 9y ago
        And I really liked the air quality when I was in Beijing two weeks ago. But that was a fluke. Most of the times, things aren't as rosy.
        Hydraulix989 9y ago
        Pretty sure the weather is always the way it was when I was there every December, so not a fluke.
    - vacri 9y ago
      > typhoons all the time Spare a thought for the Philippines - the wikipedia typhoon path picture almost completely covers the entire country (HK is hidden in there too, though) https://en.wikipedia.org/wiki/Typhoon#/media/File:Pacific_typhoon_tracks_1980-2005.jpg https://en.wikipedia.org/wiki/Typhoon#/media/File:Pacific_ty...
  - exergy 9y ago
    In India, we employed a variety of methods that, all combined, did a good enough job of keeping things cool. The first was a stepwell, called Baoli in Hindi. This was basically a giant swimming pool dug out and filled with water. Around the stepwell, terrace-like steps were created where the general public could hang out and stay cool. For example[1]. Another method was to have dual walls with some lattice patterns on the first wall. The first wall absorbed all of the heat and would get warm in the evening, but the second wall, recessed from the first wall by a certain distance, would be spared the hot sunshine, and would stay cooler. These second walls made up the walls of your room. Moving to basements was also a popular solution, since beneath the earth stayed cooler. The British especially loved this solution. Older homes in India have high ceilings with ventilation at the top to allow for natural convection. The hot air would escape from the top and be replaced with cool air. In places like New Orleans, the Creole architecture also involves inlet vents in the basement-region, where cooler air would be sucked in. Finally, after the arrival of electricity, we had evaporative coolers, where pads made out of hay would have water dripped onto them. The evaporation of the water would cool things down inside the cooler via latent heat, and this cooler air would be blown into a room with the exhaust fan. This is a fantastic solution for dry heat places because it doesn't get rid of humidity (making the skin feel terrible), and has the power consumption only of a puny exhaust fan (unlike a full blown positive displacement compressor). [1]: https://upload.wikimedia.org/wikipedia/commons/e/ee/ChandBaori.jpg https://upload.wikimedia.org/wikipedia/commons/e/ee/ChandBao...
    - zild3d 9y ago
      you can swim in that water?
      - logfromblammo 9y ago
        You can, but you probably shouldn't. Even if you don't get an infection, you would certainly be ejected or arrested for misbehaving at a historical landmark site.
- flexie 9y ago
  Funny, I remember coming to NYC from Scandinavia thinking it was so humid and warm and impossible to get anything done during the summer months. Guess it really depends on what you are used to. Then, in the winter, the old NYC apartments were so dry and warm because of the central heat that typically couldn't be regulated from the radiators in the apartments. They just blasted on all winter and the only way to adjust the temperature would be to open the windows :-)
  - seanmcdirmid 9y ago
    In Beijing, we had central CITY heating in the winter. It was so toasty I would open my window whenever the air pollution wasn't took bad. During the summer, it was hot and humid. Unfortunately, centra AC wasn't a thing, and the wall units would only do so much. Now I live in LA and the weather is mostly perfect.
  - nemo44x 9y ago
    It is humid and warm in NYC but it hasn't been this year yet. But it will come and the inside of apartments will be amplified. Most building are side by side with no windows on the side. And unites tend to only have windows on a single side which means it's impossible to get airflow. As for radiators some can be adjusted but many are binary, either on or off. You could always turn one off for awhile too. They stay warm for quite awhile when off.
- kijin 9y ago
  Every summer, I see a couple of posts on HN about some supposedly groundbreaking scheme to cool a building by a few degrees without using an traditional A/C. Usually it's a combination of ventilation and evaporation, resulting in somewhat cooler but much more humid air. I guess it might work in the Bay Area. But as someone who lives where I regularly see temperatures higher than the human body temperature with humidity higher than the human body's water content, that kind of scheme is an absolute non-starter. This article does a great job explaining why. The fact that blowing air over blocks of ice didn't work 100 years ago should remind today's inventors that damp air is unlikely to be a good solution, either, in most parts the world that currently rely on compressor-based air conditioners.
  - seanmcdirmid 9y ago
    Most people in the Bay Area don't need AC. Swamp coolers don't work in the tropics, obviously. They are great in the desert though (except during monsoon season). In the tropics, you cool by extracting humidity, not injecting it. And extracting humidity might not work very well in a very dry desert...so... The ice block thing worked perfectly fine in Iran, at least.
    - jogjayr 9y ago
      > Most people in the Bay Area don't need AC. I second that. The Bay Area has this gloriously perfect climate where you need nothing more than a table or ceiling fan in the summer, a small electric space heater in the winter and nothing at all most of the time. With the right architecture and insulation you could spend almost nothing on heating or cooling.
    - kijin 9y ago
      > In the tropics, you cool by extracting humidity, not injecting it. And extracting humidity might not work very well in a very dry desert...so... You seem to be saying that an air conditioner requires significant ambient humidity in order to be effective. That doesn't make sense, as anyone from Phoenix, Arizona can testify. A typical air conditioner does not cool the air by extracting humidity. It extracts humidity by cooling the air and so bringing it below its condensation point. Extracting humidity is a welcome side effect, since it helps us feel more comfortable, but it is not the primary function of a modern air conditioner.
- tehlike 9y ago
  I have just been to one of these tropical places, I can relate. Super hard to breathe outside, and getting inside feels like a relief.
- L_Rahman 9y ago
  I grew up in Bangladesh and I promise you there will be summer days in NY that will just as sweltering as the warmest, muggiest, air sticks to your body days in South Asia. Might be good to buy an AC before then ;)
- tluyben2 9y ago
  I guess it depends on what you are used to. I get distracted by being too cold (ACs included); if it's hot I don't have it. I get a lot more done in humid 40C Thailand(etc) then I get done in cold, rainy London in the same timespan. Programming that is; for meetings cold is better I think.
- nemo44x 9y ago
  When did you move to NYC? It hasn't gotten hot yet this year but you'll see that living without an AC or a fan is hell here. The inside of apartments (especially older ones which most are) gets amazingly hot and it stays that way once it heats up outside. It has been a rather cool spring and we haven't had a heat wave yet but rest assured once we do you will find inside your apartment will be unbearably hot and humid. And it will stay that way well into autumn. The city itself gets hot too with a lack of airflow and tons of AC units pushing out heat and exhaust from vehicles and the Subway as well. The Subway stations will be unbearably hot as well since the train is air conditioned and has lots of heat exhaust from this and its regular operation. Luckily apartments are small enough that a decent window AC can usually keep an entire unit comfortable and only has to be run when you're home.
  - miketuritzin 9y ago
    It has been quite cool so far this year. My experience moving to NYC from northern CA three years ago has been: 1st summer (2014) I got by without an AC (but with fans) and it wasn't that bad. 2nd summer (2015) was quite agonizingly hot and humid and I vowed to get an AC for the next year. 3rd summer (2016) I had an AC and was very glad as it was quite hot that year as well.
jay-anderson 9y ago
> A study in Phoenix, Arizona, found the hot air pumped out of air conditioning units increased the city's night-time temperature by 2C Often I wish places of business and work places wouldn't turn up the AC so much. I have a jacket at work in Phoenix during the summer because they keep it so cold.
- huac 9y ago
  Some trading floors keep it very chilly in order to keep traders awake (and issue fleeces to keep the rest of their body warm).
- pitaj 9y ago
  Better have it too cold and people where extra clothing than have people sweating themselves. You can always put more clothes on, you can't take off your skin.
  - nsxwolf 9y ago
    It's easy to get warm; hard to get cold.
    - barrkel 9y ago
      It's not so easy to protect e.g. your wrists from the cold desk.
      - PhasmaFelis 9y ago
        How not? I can't imagine long sleeves or a jacket not being enough, but if so, just put down a folded towel or something.
  - projectorlochsa 9y ago
    24-25 Celsius on lowest fan settings should be cold enough for practically everyone.
    - 9y ago
OrangeTux 9y ago
Fun fact: Carrier still produces HVAC systems.
callmeed 9y ago
If you like this story, I recommend reading How We Got to Now: Six Innovations That Made the Modern World. Its a quick read and very interesting. And, yes, "cold" is one of the six. https://www.amazon.com/How-We-Got-Now-Innovations/dp/1594633932 https://www.amazon.com/How-We-Got-Now-Innovations/dp/1594633...
- LeoPanthera 9y ago
  The book is based on a PBS/BBC TV show which is also excellent. It's on the Amazon, Google, and Microsoft video stores, and questionably legal copies are also on YouTube.
- fuckemem 9y ago
  "cold" is quite broad though. That would cover refrigeration/ freezing which would be a much bigger impact than air con.
  - thaumasiotes 9y ago
    Refrigeration allows you to preserve any kind of food and eat it at any time of year. It allows food to be shipped in to remote locations, which is important. Air conditioning directly lets people live where they otherwise couldn't; it doesn't seem obvious that refrigeration is larger-impact.
  - tormeh 9y ago
    They're literally the same thing. Only difference is how big the fridge is and how much power you dedicate.
    - fuckemem 9y ago
      With the title "The far-reaching effects of air conditioning" I didn't immediately think "Yup ... that's handy: frozen peas" even though the technology underlying them is the same.
  - callmeed 9y ago
    The chapter covers both. And they impact everything from food to politics.
ishi 9y ago
The downside of air conditioned homes is that houses are now built with very little regard to insulation and intelligent use of the sun (to warm the house at winter) and the wind (to cool it during summertime). My house has a large, paper-thin southern wall and during the summer it gets so hot that it radiates heat into the house at night. So I have to air-condition my bedroom at night. And the windows are stupidly designed, so when the wind blows in the winter I can feel it enter the room - and again I must use electricity to keep the room warm. Thankfully, "green" building methods are starting to change this wasteful attitude.
- kijin 9y ago
  I wholeheartedly agree. A powerful HVAC system is not an excuse to skimp on insulation! Not only does it waste energy, it also leaves you with higher utility bills and increases the chance of condensation. Condensation is the real killer if you live in a humid climate. It damages the walls, causes mold, and can even mess with the electrical system.
- dobecker 9y ago
  That's why there's a law in germany that you have to present an Energy Performance Certificate when you sell, let or build a house/appartement. It shows how good the building is insulated and how much energy you need to cool/heat it. But then electricity is much more expensive than in the US. EDIT: Seems like this is true for all european countries
- adrianmonk 9y ago
  Being from Texas, that is such a strange perspective to me. Around here, air conditioning is the main reason why you need insulation. Heating isn't a major concern. Many houses have electric heat because it just isn't worth the cost to put in something more efficient. But air conditioning is needed a large part of the year. And in the summer it gets quite hot, so electric bills can be very expensive. So in any newer construction, there is a lot of effort to make things energy-efficient. Houses have double-pane windows, radiant barriers, thick insulation, and leak tests to make sure that hot/humid air from outside cannot make its way in. There are certainly older buildings that aren't very energy-efficient, but around here I don't see that as being because of air conditioning.
kayoone 9y ago
In places like Brazil were AC is everywhere but isolation and heating is limited, it gets really cold in the winter even if its only 15 degrees outside. In places like germany where home isolation and heating is generally very good, you really have to suffer in the summer because rarely any place apart from some offices have AC. Even more so, many don't like AC at home because it consumes a lot of power and can make you sick (not sure if this is actually true).
- ido 9y ago
  We live in Berlin and the insulation and generally high ceilings make most apartments pretty cool even in the hotter summer days (which are rare and rarely much hotter than 30c). There are maybe 2-3 weeks per year when I wish we had air conditioning, at most.
  - czechdeveloper 9y ago
    Once indoors temperature hits 26, I can't get any work done. I know I have short temperature comfort range, but 30 indoors is crazy for me.
    - lorenzhs 9y ago
      ido was talking about outside temperature. I live in one of the hottest cities in Germany (Karlsruhe) and I agree with ido. There's around 2-3 weeks where home air conditioning would really be useful. The rest of the time, temperature is controlled easily enough by opening windows at night and closing the shutters during the daytime while at the office. Air conditioning for offices is a different story.
    - ido 9y ago
      I don't think indoor temperature ever reached 30c inside my apartment (or if it did it was definitely not for long).
  - kayoone 9y ago
    i actually live in Berlin too and while Summer 2016 wasn't that bad, i remember suffering a lot in the 2015 summer heat in an office without AC. And that wasn't just a few days, it was weeks at a time.
jpatokal 9y ago
Lee Kuan Yew, founder of modern Singapore: "Air conditioning was a most important invention for us, perhaps one of the signal inventions of history. It changed the nature of civilization by making development possible in the tropics. Without air conditioning you can work only in the cool early-morning hours or at dusk. The first thing I did upon becoming prime minister was to install air conditioners in buildings where the civil service worked. This was key to public efficiency." https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew-air-conditioning https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew...
- pavlov 9y ago
  Japan is further ahead, as they have optimized this with a decade-old policy called "Cool Biz". To save energy and money by reducing AC, office workers are allowed to wear more casual clothing in the summer: https://qz.com/465327/ditch-the-tie-and-reduce-the-ac-japans-cool-biz-gets-summer-hell-just-about-right/ https://qz.com/465327/ditch-the-tie-and-reduce-the-ac-japans...
  - hueving 9y ago
    Japan isn't really ahead of Singapore in this regard due to its position much further north. The heat in Singapore is unbearable inside a building without a/c during the day. Putting on a casual shirt will hardly help in that situation.
    - 6nf 9y ago
      It does help when you go out to lunch etc, even the 5 mins from building to building can be pretty sweaty
      - dogma1138 9y ago
        Japan isn't in the tropics, south of Japan does get quite warm but Tokyo is on the 36th parallel it's not much warmer than many US cities. Japan does in general has a much stricter dress code than most other places with similar climate.
superasn 9y ago
Throughout the article I was waiting for the "But.." As in some how it also deteriorated the global weather, caused some unknown sort of pollution, etc. It was good to see that Air conditioning has only improved the world and has no side-effects.
- Tharkun 9y ago
  Or you know, wastes inordinate of energy, especially in areas where insulation and ventilation could achieve similar comfort levels.
- exodust 9y ago
  Massive energy consumption to the point of overloading power grids on hot days continues to be a problem in some areas. Massive increase in cost of electricity is due largely to the infrastructure needs of meeting peak demand events caused by sudden widespread AC use. Those who don't use AC in their homes are still paying higher prices in order that the system can cater for the people who use AC.
  - saint_fiasco 9y ago
    I think that last one is fair, because we all benefit economically from the productivity increase. Think of it as trickle-sideways economics.
    - exodust 9y ago
      I was referring to residential AC use which is much less efficient than cooling a commercial building in terms of how many people are kept cool. It's a problem here in Australia at least.
- stevoski 9y ago
  FTA: "But there's an inconvenient truth: you can only make it cooler inside by making it warmer outside." Followed by several paragraphs of the contribution of air-conditioning to hotter cities.
- 9y ago
tyng 9y ago
The same goes for washing machine: https://www.ted.com/talks/hans_rosling_and_the_magic_washing_machine https://www.ted.com/talks/hans_rosling_and_the_magic_washing... "What was the greatest invention of the industrial revolution? Hans Rosling makes the case for the washing machine. With newly designed graphics from Gapminder, Rosling shows us the magic that pops up when economic growth and electricity turn a boring wash day into an intellectual day of reading."
- vacri 9y ago
  A while back a friend of mine told me how her (great-?)grandmother in Malta used to do the laundry down the river as a young woman, and her and her friends used to dream about having a magic box that you could just throw the laundry in, press a button, and it'd be done!
TomK32 9y ago
Why did no one mention the Romans yet? They came up with the frigidarium where you could literally cool down with your friends and some private houses even had water running inside their walls to cool it down (or hot air in the colder months). Temperature control in buildings is 100% architecture and technical add-ons like AC are a poor choice. Look at termites how they use architecture to cool their hives.
- _pmf_ 9y ago
  > Temperature control in buildings is 100% architecture and technical add-ons like AC are a poor choice. Look at termites how they use architecture to cool their hives. Clay for the win. Even using a very thin clay based upper layer does incredible things to the room climate.
  - bryanrasmussen 9y ago
    is Clay also for the win in hot, humid climates?
    - nf05papsjfVbc 9y ago
      Yes, it works fairly well. You need to have a high ceiling for it to be effective though. I don't know why that is so, however.
- Xylakant 9y ago
  > Temperature control in buildings is 100% architecture and technical add-ons like AC are a poor choice. AC is not only temperature control. Running water through the walls or evaporation cooling only work in moderately dry climates but will not help much in humid climates. Cooling the walls will just lead to condensation and wet walls. There's certainly a lot that can be done without AC, but humidity control is required in some regions of the world.
- ComputerGuru 9y ago
  The article does mention the Romans, though: > The eccentric Roman emperor Elagabulus sent slaves to bring snow down from the mountains and pile it in his garden, where breezes would carry the cooler air inside.
h20sdvaid 9y ago
Wow, it has to be 35c/95f before it is hot. Living in Australia on one mine site the daily temperature was 45c/113f at night 32 c/90f Amazing how you get used to the temperature. Joys of working in a desert in Summertime. Never use air conditioning no good for my health. And yes termites are pretty smart in keeping things cool
- hvidgaard 9y ago
  Humidity plays a huge role in this. In dry climates, it can be 30-40c without too much problem, you just need to hydrate a lot. If it's humid, then even 25c can be very uncomfortable.
euoia 9y ago
There is a great TV series called "The Secret Life of Machines" that covered some inventions that changed the world: https://www.youtube.com/watch?v=KDpNQQqdSh8&list=PLByTa5duIolYRtq45Cz_GmtzfWJyA4bik&spfreload=5 https://www.youtube.com/watch?v=KDpNQQqdSh8&list=PLByTa5duIo... There is an episode on central heating: https://www.youtube.com/watch?v=9y08yBdoFsI https://www.youtube.com/watch?v=9y08yBdoFsI
woofyman 9y ago
In the Southern USA, AC radically changed the culture. It allowed businesses to relocate their factories to take advantage of cheap labor. It also changed a slower paced culture where people spent their evenings on their front porch socializing with their neighbors to a more insular, face paced one. I grew up in South Florida without AC.
spodek 9y ago
Low-tech magazine has an article on how useful ceiling fans are: http://www.lowtechmagazine.com/2014/09/circulating-fans-air-conditioning.html http://www.lowtechmagazine.com/2014/09/circulating-fans-air-.... They don't pollute nearly as much and work remarkably well. I live in Manhattan, which gets hot and humid in the summer, and basically never turn on my air conditioning even though I pay for my share of the building's central air conditioning. I don't need it and prefer not to cause the pollution.
- NoGravitas 9y ago
  Here in the South, ceiling fans will let you keep your AC on 80F and still be comfortable. High ceilings help, too, but they're not as common as they used to be.
  - saint_fiasco 9y ago
    High ceilings probably mean keeping your AC on 80F doesn't save as much power as you expect, because it has to cool a larger volume of space.
    - logfromblammo 9y ago
      You're not adding cool, but removing heat. And you're not doing it for the entire volume, but for the 2m layer nearest the floor. Those high ceilings make it easier to remove heat from that bottom layer, especially with drop ceilings, plenum spaces, insulating spaces, and fans. You are cooling a larger volume of air, but it is not to a uniform 80 degF. The higher layers will be cooled to a lesser extent than the lower layers, so the AC burden is somewhat less overall than if the entire room volume were cooled to a uniformly low temperature.
neals 9y ago
Let's not forget about health and the breeding ground for pathogens and bacteria that AC's are. I used to get really bad colds and coughs during summer, when the AC's went on. I now carry a spray that puts bacteria in the air that displace other bacteria and no colds and coughs anymore. But that's not mainstream. There's probably a lot of sick people out there, thanks to AC.
- LeifCarrotson 9y ago
  > I now carry a spray that puts bacteria in the air that displace other bacteria and no colds and coughs anymore. But that's not mainstream. No, it's not, I've never heard of it! I'm pretty skeptical of new medical claims, though, and I'm curious about this description. From my limited understanding, don't think the bacteria in air are like a bathtub full of objects that take up space, or like an ecosystem that compete for resources and reach an equilibrium: it's more like an ocean full of fish, where spraying more fish into the water aren't going to do much about the existing sharks. Can you provide a link or description of this product? > There's probably a lot of sick people out there, thanks to AC. This is also a claim I find surprising. Air conditioners are ubiquitous around here in the summer, but I've never heard of a health risk from them. I'm aware that the cheap window units can develop condensation puddles if improperly installed (I cleaned one out in my old apartment that was disgusting), but the typical business has central air and I thought it actually improved the microbial situation by dehumidifying the air. Citations for this claim?
  - nerdshoe 9y ago
    Legionnaire's disease thrives in air conditioners https://en.wikipedia.org/wiki/Legionnaires%27_disease https://en.wikipedia.org/wiki/Legionnaires%27_disease
    - LeifCarrotson 9y ago
      There's little risk of disease (Specifically, Legionnaires') from residential air-cooled A/C systems. The risk is typically from industrial air conditioning systems which use a water-based heat exchanger between a radiator system on the roof and the condenser. The water in this system is kept warm. The water in the condensate tray of a typical AC is cold and continually drained, so the disease doesn't propagate well.
jaboutboul 9y ago
Odd that no one here has made any comments on the correlation of the massive boom in air conditioning in the last 30 years around the world and climate change. Wouldn't it seem like having an ever increasing number of these things, humming constantly in both hemispheres all throughout the year and generating loads of hot air and greenhouse gases, is a significant contributor (even maybe main contributor) to the global rise in temperature?
- btbuildem 9y ago
  That, and they insulate us from the effects of climate change. Out of sight, out of mind, right?
robg 9y ago
Surprised the word "sleep" doesn't appear in the article. Sleeping well is what best prepares us for productivity the following day. https://www.nytimes.com/2017/05/26/climate/global-warming-sleep-loss.html https://www.nytimes.com/2017/05/26/climate/global-warming-sl...
rudedogg 9y ago
I live in an area where evaporative coolers are effective. I hate setting it up every year, and was looking into central air. When researching I learned about how efficient evaporative coolers are, and it gave me more appreciation for them. https://en.wikipedia.org/wiki/Evaporative_cooler https://en.wikipedia.org/wiki/Evaporative_cooler: * Estimated cost of operation is 1/8 that of refrigerated air conditioning It's really interesting to think about the advantages/disadvantages of geography in regards to power generation/consumption. It didn't really occur to me until going through the above experience. ---------------- The design of these systems is really interesting. Most of them have a lot of wearable parts (belt and bearings), which means more maintenance. There are some new designs (http://www.bonaire-usa.com/products.html#window http://www.bonaire-usa.com/products.html#window) that do away with the "squirrel cage" fan (https://en.wikipedia.org/wiki/Centrifugal_fan https://en.wikipedia.org/wiki/Centrifugal_fan), and a lot of the maintenance. I wonder if the efficiency of the new design is lower than the traditional centrifugal fan design? I know this can be found - I just don't want to go too deep researching. If anyone knows off hand I'd appreciate an answer!
- humanrebar 9y ago
  > It's really interesting to think about the advantages/disadvantages of geography in regards to power generation/consumption. I've seen air conditioning that amounted to basically a shaft into a natural underground cave and a fan. I've also heard of people watering the roofs of their houses in the summer to get low-tech just-in-time evaporative cooling for their attics.
  - rudedogg 9y ago
    The cave thing is neat - sounds like an easy form of https://en.wikipedia.org/wiki/Geothermal_heating https://en.wikipedia.org/wiki/Geothermal_heating
- cr0sh 9y ago
  > I wonder if the efficiency of the new design is lower than the traditional centrifugal fan design? It depends. They each have their pros and cons: https://en.wikipedia.org/wiki/Centrifugal_fan https://en.wikipedia.org/wiki/Centrifugal_fan http://www.pelonistechnologies.com/blog/axial-vs.-centrifugal-fans http://www.pelonistechnologies.com/blog/axial-vs.-centrifuga... (might be somewhat biased) https://en.wikipedia.org/wiki/Fan_(machine) https://en.wikipedia.org/wiki/Fan_(machine) Unfortunately I couldn't find anything on axial fan efficiency or whatnot, compared to centrifugal fans. In general, though, if I had to pick one I'd go with the centrifugal fan for cooling purposes; they seem to move air much better than axial fans. They do make direct-drive centrifugal fans, but I am not sure if they exist in large versions for home cooling systems. They are made for use in computers, as well as for smaller (but still large) units like blowers for drying and for things like "air curtains" and smaller blowers for small air-conditioning systems.
setgree 9y ago
I thought -- this is a very pro-capitalist piece for the BBC! And then saw the byline :)
triangleman 9y ago
Not mentioned in the article: Air conditioning makes it possible to stay indoors, away from mosquitoes, thus fighting illnesses like malaria and zika.
iamthepieman 9y ago
From the OP "Historically, a cool building in a hot climate implied thick walls, high ceilings, balconies, courtyards and windows facing away from the sun." New Orleans is one of the clearest examples of this hot and humid specific architecture[0]. In that picture the second floor balcony represents roughly the height of the 1st floor ceiling. The many doors like porticos, can be opened on the shaded side of the building allowing for air flow. You see this style all over the city. Apart from reflective coatings on glass in high rises and office buildings and the occasional Leed certified building trying to save on energy usage, you don't see much architectural consideration for the climate. This is especially true in office buildings (in the U.S. anyways) built 1900-1950 or so with blocky brick buildings in which the central rooms have little natural ventilation[1] [0]https://www.google.com/maps/@29.9459548,-90.0658908,3a,75y,269.21h,85.25t/data=!3m6!1e1!3m4!1shFaAE9ft5lzkP8_FWgB0XA!2e0!7i13312!8i6656 https://www.google.com/maps/@29.9459548,-90.0658908,3a,75y,2... [1] http://forgotten-ny.com/wp-content/uploads/2005/01/e149stbusher1.jpg http://forgotten-ny.com/wp-content/uploads/2005/01/e149stbus...

216 points by unsupported 9y ago

Unless you have lived in the tropical humid heat, you wont be able to relate to this. Moving to NYC recently and living without an AC or even a fan feels so glorious. I bet 10% of my brain was constantly fighting the heat back when I was in south of India.

hobo_mark 9y ago
Likewise, I just came back from HK and I have no idea how they could get anything done there before the introduction of AC. And I was told it gets even worse in the middle of summer!
- SeoxyS 9y ago
  I went to HK in the middle of hottest times (Aug 1st) last year and it was absolutely brutal. But then again, the entire city really grew out of nowhere during the past century, so it kind of grew in tandem with air conditioning. HK is one of those places that's absolutely amazing as a city, and has some of the worst weather on earth (crazy humidity all the time, insane heat in summer, crazy rains and typhoons all the time… and a cloud of pollution emanating down from Shenzhen).
  - Hydraulix989 9y ago
    I really liked the weather there when I went in December.
    - SeoxyS 9y ago
      And I really liked the air quality when I was in Beijing two weeks ago. But that was a fluke. Most of the times, things aren't as rosy.
      - Hydraulix989 9y ago
        Pretty sure the weather is always the way it was when I was there every December, so not a fluke.
  - vacri 9y ago
    > typhoons all the time Spare a thought for the Philippines - the wikipedia typhoon path picture almost completely covers the entire country (HK is hidden in there too, though) https://en.wikipedia.org/wiki/Typhoon#/media/File:Pacific_typhoon_tracks_1980-2005.jpg https://en.wikipedia.org/wiki/Typhoon#/media/File:Pacific_ty...
- exergy 9y ago
  In India, we employed a variety of methods that, all combined, did a good enough job of keeping things cool. The first was a stepwell, called Baoli in Hindi. This was basically a giant swimming pool dug out and filled with water. Around the stepwell, terrace-like steps were created where the general public could hang out and stay cool. For example[1]. Another method was to have dual walls with some lattice patterns on the first wall. The first wall absorbed all of the heat and would get warm in the evening, but the second wall, recessed from the first wall by a certain distance, would be spared the hot sunshine, and would stay cooler. These second walls made up the walls of your room. Moving to basements was also a popular solution, since beneath the earth stayed cooler. The British especially loved this solution. Older homes in India have high ceilings with ventilation at the top to allow for natural convection. The hot air would escape from the top and be replaced with cool air. In places like New Orleans, the Creole architecture also involves inlet vents in the basement-region, where cooler air would be sucked in. Finally, after the arrival of electricity, we had evaporative coolers, where pads made out of hay would have water dripped onto them. The evaporation of the water would cool things down inside the cooler via latent heat, and this cooler air would be blown into a room with the exhaust fan. This is a fantastic solution for dry heat places because it doesn't get rid of humidity (making the skin feel terrible), and has the power consumption only of a puny exhaust fan (unlike a full blown positive displacement compressor). [1]: https://upload.wikimedia.org/wikipedia/commons/e/ee/ChandBaori.jpg https://upload.wikimedia.org/wikipedia/commons/e/ee/ChandBao...
  - zild3d 9y ago
    you can swim in that water?
    - logfromblammo 9y ago
      You can, but you probably shouldn't. Even if you don't get an infection, you would certainly be ejected or arrested for misbehaving at a historical landmark site.
flexie 9y ago
Funny, I remember coming to NYC from Scandinavia thinking it was so humid and warm and impossible to get anything done during the summer months. Guess it really depends on what you are used to. Then, in the winter, the old NYC apartments were so dry and warm because of the central heat that typically couldn't be regulated from the radiators in the apartments. They just blasted on all winter and the only way to adjust the temperature would be to open the windows :-)
- seanmcdirmid 9y ago
  In Beijing, we had central CITY heating in the winter. It was so toasty I would open my window whenever the air pollution wasn't took bad. During the summer, it was hot and humid. Unfortunately, centra AC wasn't a thing, and the wall units would only do so much. Now I live in LA and the weather is mostly perfect.
- nemo44x 9y ago
  It is humid and warm in NYC but it hasn't been this year yet. But it will come and the inside of apartments will be amplified. Most building are side by side with no windows on the side. And unites tend to only have windows on a single side which means it's impossible to get airflow. As for radiators some can be adjusted but many are binary, either on or off. You could always turn one off for awhile too. They stay warm for quite awhile when off.
kijin 9y ago
Every summer, I see a couple of posts on HN about some supposedly groundbreaking scheme to cool a building by a few degrees without using an traditional A/C. Usually it's a combination of ventilation and evaporation, resulting in somewhat cooler but much more humid air. I guess it might work in the Bay Area. But as someone who lives where I regularly see temperatures higher than the human body temperature with humidity higher than the human body's water content, that kind of scheme is an absolute non-starter. This article does a great job explaining why. The fact that blowing air over blocks of ice didn't work 100 years ago should remind today's inventors that damp air is unlikely to be a good solution, either, in most parts the world that currently rely on compressor-based air conditioners.
- seanmcdirmid 9y ago
  Most people in the Bay Area don't need AC. Swamp coolers don't work in the tropics, obviously. They are great in the desert though (except during monsoon season). In the tropics, you cool by extracting humidity, not injecting it. And extracting humidity might not work very well in a very dry desert...so... The ice block thing worked perfectly fine in Iran, at least.
  - jogjayr 9y ago
    > Most people in the Bay Area don't need AC. I second that. The Bay Area has this gloriously perfect climate where you need nothing more than a table or ceiling fan in the summer, a small electric space heater in the winter and nothing at all most of the time. With the right architecture and insulation you could spend almost nothing on heating or cooling.
  - kijin 9y ago
    > In the tropics, you cool by extracting humidity, not injecting it. And extracting humidity might not work very well in a very dry desert...so... You seem to be saying that an air conditioner requires significant ambient humidity in order to be effective. That doesn't make sense, as anyone from Phoenix, Arizona can testify. A typical air conditioner does not cool the air by extracting humidity. It extracts humidity by cooling the air and so bringing it below its condensation point. Extracting humidity is a welcome side effect, since it helps us feel more comfortable, but it is not the primary function of a modern air conditioner.
tehlike 9y ago
I have just been to one of these tropical places, I can relate. Super hard to breathe outside, and getting inside feels like a relief.
L_Rahman 9y ago
I grew up in Bangladesh and I promise you there will be summer days in NY that will just as sweltering as the warmest, muggiest, air sticks to your body days in South Asia. Might be good to buy an AC before then ;)
tluyben2 9y ago
I guess it depends on what you are used to. I get distracted by being too cold (ACs included); if it's hot I don't have it. I get a lot more done in humid 40C Thailand(etc) then I get done in cold, rainy London in the same timespan. Programming that is; for meetings cold is better I think.
nemo44x 9y ago
When did you move to NYC? It hasn't gotten hot yet this year but you'll see that living without an AC or a fan is hell here. The inside of apartments (especially older ones which most are) gets amazingly hot and it stays that way once it heats up outside. It has been a rather cool spring and we haven't had a heat wave yet but rest assured once we do you will find inside your apartment will be unbearably hot and humid. And it will stay that way well into autumn. The city itself gets hot too with a lack of airflow and tons of AC units pushing out heat and exhaust from vehicles and the Subway as well. The Subway stations will be unbearably hot as well since the train is air conditioned and has lots of heat exhaust from this and its regular operation. Luckily apartments are small enough that a decent window AC can usually keep an entire unit comfortable and only has to be run when you're home.
- miketuritzin 9y ago
  It has been quite cool so far this year. My experience moving to NYC from northern CA three years ago has been: 1st summer (2014) I got by without an AC (but with fans) and it wasn't that bad. 2nd summer (2015) was quite agonizingly hot and humid and I vowed to get an AC for the next year. 3rd summer (2016) I had an AC and was very glad as it was quite hot that year as well.

jay-anderson 9y ago

> A study in Phoenix, Arizona, found the hot air pumped out of air conditioning units increased the city's night-time temperature by 2C Often I wish places of business and work places wouldn't turn up the AC so much. I have a jacket at work in Phoenix during the summer because they keep it so cold.

huac 9y ago
Some trading floors keep it very chilly in order to keep traders awake (and issue fleeces to keep the rest of their body warm).
pitaj 9y ago
Better have it too cold and people where extra clothing than have people sweating themselves. You can always put more clothes on, you can't take off your skin.
- nsxwolf 9y ago
  It's easy to get warm; hard to get cold.
  - barrkel 9y ago
    It's not so easy to protect e.g. your wrists from the cold desk.
    - PhasmaFelis 9y ago
      How not? I can't imagine long sleeves or a jacket not being enough, but if so, just put down a folded towel or something.
- projectorlochsa 9y ago
  24-25 Celsius on lowest fan settings should be cold enough for practically everyone.
  - 9y ago

OrangeTux 9y ago

Fun fact: Carrier still produces HVAC systems.

callmeed 9y ago

If you like this story, I recommend reading How We Got to Now: Six Innovations That Made the Modern World. Its a quick read and very interesting. And, yes, "cold" is one of the six. https://www.amazon.com/How-We-Got-Now-Innovations/dp/1594633932 https://www.amazon.com/How-We-Got-Now-Innovations/dp/1594633...

LeoPanthera 9y ago
The book is based on a PBS/BBC TV show which is also excellent. It's on the Amazon, Google, and Microsoft video stores, and questionably legal copies are also on YouTube.
fuckemem 9y ago
"cold" is quite broad though. That would cover refrigeration/ freezing which would be a much bigger impact than air con.
- thaumasiotes 9y ago
  Refrigeration allows you to preserve any kind of food and eat it at any time of year. It allows food to be shipped in to remote locations, which is important. Air conditioning directly lets people live where they otherwise couldn't; it doesn't seem obvious that refrigeration is larger-impact.
- tormeh 9y ago
  They're literally the same thing. Only difference is how big the fridge is and how much power you dedicate.
  - fuckemem 9y ago
    With the title "The far-reaching effects of air conditioning" I didn't immediately think "Yup ... that's handy: frozen peas" even though the technology underlying them is the same.
- callmeed 9y ago
  The chapter covers both. And they impact everything from food to politics.

ishi 9y ago

The downside of air conditioned homes is that houses are now built with very little regard to insulation and intelligent use of the sun (to warm the house at winter) and the wind (to cool it during summertime). My house has a large, paper-thin southern wall and during the summer it gets so hot that it radiates heat into the house at night. So I have to air-condition my bedroom at night. And the windows are stupidly designed, so when the wind blows in the winter I can feel it enter the room - and again I must use electricity to keep the room warm. Thankfully, "green" building methods are starting to change this wasteful attitude.

kijin 9y ago
I wholeheartedly agree. A powerful HVAC system is not an excuse to skimp on insulation! Not only does it waste energy, it also leaves you with higher utility bills and increases the chance of condensation. Condensation is the real killer if you live in a humid climate. It damages the walls, causes mold, and can even mess with the electrical system.
dobecker 9y ago
That's why there's a law in germany that you have to present an Energy Performance Certificate when you sell, let or build a house/appartement. It shows how good the building is insulated and how much energy you need to cool/heat it. But then electricity is much more expensive than in the US. EDIT: Seems like this is true for all european countries
adrianmonk 9y ago
Being from Texas, that is such a strange perspective to me. Around here, air conditioning is the main reason why you need insulation. Heating isn't a major concern. Many houses have electric heat because it just isn't worth the cost to put in something more efficient. But air conditioning is needed a large part of the year. And in the summer it gets quite hot, so electric bills can be very expensive. So in any newer construction, there is a lot of effort to make things energy-efficient. Houses have double-pane windows, radiant barriers, thick insulation, and leak tests to make sure that hot/humid air from outside cannot make its way in. There are certainly older buildings that aren't very energy-efficient, but around here I don't see that as being because of air conditioning.

kayoone 9y ago

In places like Brazil were AC is everywhere but isolation and heating is limited, it gets really cold in the winter even if its only 15 degrees outside. In places like germany where home isolation and heating is generally very good, you really have to suffer in the summer because rarely any place apart from some offices have AC. Even more so, many don't like AC at home because it consumes a lot of power and can make you sick (not sure if this is actually true).

ido 9y ago
We live in Berlin and the insulation and generally high ceilings make most apartments pretty cool even in the hotter summer days (which are rare and rarely much hotter than 30c). There are maybe 2-3 weeks per year when I wish we had air conditioning, at most.
- czechdeveloper 9y ago
  Once indoors temperature hits 26, I can't get any work done. I know I have short temperature comfort range, but 30 indoors is crazy for me.
  - lorenzhs 9y ago
    ido was talking about outside temperature. I live in one of the hottest cities in Germany (Karlsruhe) and I agree with ido. There's around 2-3 weeks where home air conditioning would really be useful. The rest of the time, temperature is controlled easily enough by opening windows at night and closing the shutters during the daytime while at the office. Air conditioning for offices is a different story.
  - ido 9y ago
    I don't think indoor temperature ever reached 30c inside my apartment (or if it did it was definitely not for long).
- kayoone 9y ago
  i actually live in Berlin too and while Summer 2016 wasn't that bad, i remember suffering a lot in the 2015 summer heat in an office without AC. And that wasn't just a few days, it was weeks at a time.

jpatokal 9y ago

Lee Kuan Yew, founder of modern Singapore: "Air conditioning was a most important invention for us, perhaps one of the signal inventions of history. It changed the nature of civilization by making development possible in the tropics. Without air conditioning you can work only in the cool early-morning hours or at dusk. The first thing I did upon becoming prime minister was to install air conditioners in buildings where the civil service worked. This was key to public efficiency." https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew-air-conditioning https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew...

pavlov 9y ago
Japan is further ahead, as they have optimized this with a decade-old policy called "Cool Biz". To save energy and money by reducing AC, office workers are allowed to wear more casual clothing in the summer: https://qz.com/465327/ditch-the-tie-and-reduce-the-ac-japans-cool-biz-gets-summer-hell-just-about-right/ https://qz.com/465327/ditch-the-tie-and-reduce-the-ac-japans...
- hueving 9y ago
  Japan isn't really ahead of Singapore in this regard due to its position much further north. The heat in Singapore is unbearable inside a building without a/c during the day. Putting on a casual shirt will hardly help in that situation.
  - 6nf 9y ago
    It does help when you go out to lunch etc, even the 5 mins from building to building can be pretty sweaty
    - dogma1138 9y ago
      Japan isn't in the tropics, south of Japan does get quite warm but Tokyo is on the 36th parallel it's not much warmer than many US cities. Japan does in general has a much stricter dress code than most other places with similar climate.

superasn 9y ago

Throughout the article I was waiting for the "But.." As in some how it also deteriorated the global weather, caused some unknown sort of pollution, etc. It was good to see that Air conditioning has only improved the world and has no side-effects.

Tharkun 9y ago
Or you know, wastes inordinate of energy, especially in areas where insulation and ventilation could achieve similar comfort levels.
exodust 9y ago
Massive energy consumption to the point of overloading power grids on hot days continues to be a problem in some areas. Massive increase in cost of electricity is due largely to the infrastructure needs of meeting peak demand events caused by sudden widespread AC use. Those who don't use AC in their homes are still paying higher prices in order that the system can cater for the people who use AC.
- saint_fiasco 9y ago
  I think that last one is fair, because we all benefit economically from the productivity increase. Think of it as trickle-sideways economics.
  - exodust 9y ago
    I was referring to residential AC use which is much less efficient than cooling a commercial building in terms of how many people are kept cool. It's a problem here in Australia at least.
stevoski 9y ago
FTA: "But there's an inconvenient truth: you can only make it cooler inside by making it warmer outside." Followed by several paragraphs of the contribution of air-conditioning to hotter cities.
9y ago

tyng 9y ago

The same goes for washing machine: https://www.ted.com/talks/hans_rosling_and_the_magic_washing_machine https://www.ted.com/talks/hans_rosling_and_the_magic_washing... "What was the greatest invention of the industrial revolution? Hans Rosling makes the case for the washing machine. With newly designed graphics from Gapminder, Rosling shows us the magic that pops up when economic growth and electricity turn a boring wash day into an intellectual day of reading."

vacri 9y ago
A while back a friend of mine told me how her (great-?)grandmother in Malta used to do the laundry down the river as a young woman, and her and her friends used to dream about having a magic box that you could just throw the laundry in, press a button, and it'd be done!

TomK32 9y ago

Why did no one mention the Romans yet? They came up with the frigidarium where you could literally cool down with your friends and some private houses even had water running inside their walls to cool it down (or hot air in the colder months). Temperature control in buildings is 100% architecture and technical add-ons like AC are a poor choice. Look at termites how they use architecture to cool their hives.

_pmf_ 9y ago
> Temperature control in buildings is 100% architecture and technical add-ons like AC are a poor choice. Look at termites how they use architecture to cool their hives. Clay for the win. Even using a very thin clay based upper layer does incredible things to the room climate.
- bryanrasmussen 9y ago
  is Clay also for the win in hot, humid climates?
  - nf05papsjfVbc 9y ago
    Yes, it works fairly well. You need to have a high ceiling for it to be effective though. I don't know why that is so, however.
Xylakant 9y ago
> Temperature control in buildings is 100% architecture and technical add-ons like AC are a poor choice. AC is not only temperature control. Running water through the walls or evaporation cooling only work in moderately dry climates but will not help much in humid climates. Cooling the walls will just lead to condensation and wet walls. There's certainly a lot that can be done without AC, but humidity control is required in some regions of the world.
ComputerGuru 9y ago
The article does mention the Romans, though: > The eccentric Roman emperor Elagabulus sent slaves to bring snow down from the mountains and pile it in his garden, where breezes would carry the cooler air inside.

h20sdvaid 9y ago

Wow, it has to be 35c/95f before it is hot. Living in Australia on one mine site the daily temperature was 45c/113f at night 32 c/90f Amazing how you get used to the temperature. Joys of working in a desert in Summertime. Never use air conditioning no good for my health. And yes termites are pretty smart in keeping things cool

hvidgaard 9y ago
Humidity plays a huge role in this. In dry climates, it can be 30-40c without too much problem, you just need to hydrate a lot. If it's humid, then even 25c can be very uncomfortable.

euoia 9y ago

There is a great TV series called "The Secret Life of Machines" that covered some inventions that changed the world: https://www.youtube.com/watch?v=KDpNQQqdSh8&list=PLByTa5duIolYRtq45Cz_GmtzfWJyA4bik&spfreload=5 https://www.youtube.com/watch?v=KDpNQQqdSh8&list=PLByTa5duIo... There is an episode on central heating: https://www.youtube.com/watch?v=9y08yBdoFsI https://www.youtube.com/watch?v=9y08yBdoFsI

woofyman 9y ago

In the Southern USA, AC radically changed the culture. It allowed businesses to relocate their factories to take advantage of cheap labor. It also changed a slower paced culture where people spent their evenings on their front porch socializing with their neighbors to a more insular, face paced one. I grew up in South Florida without AC.

spodek 9y ago

Low-tech magazine has an article on how useful ceiling fans are: http://www.lowtechmagazine.com/2014/09/circulating-fans-air-conditioning.html http://www.lowtechmagazine.com/2014/09/circulating-fans-air-.... They don't pollute nearly as much and work remarkably well. I live in Manhattan, which gets hot and humid in the summer, and basically never turn on my air conditioning even though I pay for my share of the building's central air conditioning. I don't need it and prefer not to cause the pollution.

NoGravitas 9y ago
Here in the South, ceiling fans will let you keep your AC on 80F and still be comfortable. High ceilings help, too, but they're not as common as they used to be.
- saint_fiasco 9y ago
  High ceilings probably mean keeping your AC on 80F doesn't save as much power as you expect, because it has to cool a larger volume of space.
  - logfromblammo 9y ago
    You're not adding cool, but removing heat. And you're not doing it for the entire volume, but for the 2m layer nearest the floor. Those high ceilings make it easier to remove heat from that bottom layer, especially with drop ceilings, plenum spaces, insulating spaces, and fans. You are cooling a larger volume of air, but it is not to a uniform 80 degF. The higher layers will be cooled to a lesser extent than the lower layers, so the AC burden is somewhat less overall than if the entire room volume were cooled to a uniformly low temperature.

neals 9y ago

Let's not forget about health and the breeding ground for pathogens and bacteria that AC's are. I used to get really bad colds and coughs during summer, when the AC's went on. I now carry a spray that puts bacteria in the air that displace other bacteria and no colds and coughs anymore. But that's not mainstream. There's probably a lot of sick people out there, thanks to AC.

LeifCarrotson 9y ago
> I now carry a spray that puts bacteria in the air that displace other bacteria and no colds and coughs anymore. But that's not mainstream. No, it's not, I've never heard of it! I'm pretty skeptical of new medical claims, though, and I'm curious about this description. From my limited understanding, don't think the bacteria in air are like a bathtub full of objects that take up space, or like an ecosystem that compete for resources and reach an equilibrium: it's more like an ocean full of fish, where spraying more fish into the water aren't going to do much about the existing sharks. Can you provide a link or description of this product? > There's probably a lot of sick people out there, thanks to AC. This is also a claim I find surprising. Air conditioners are ubiquitous around here in the summer, but I've never heard of a health risk from them. I'm aware that the cheap window units can develop condensation puddles if improperly installed (I cleaned one out in my old apartment that was disgusting), but the typical business has central air and I thought it actually improved the microbial situation by dehumidifying the air. Citations for this claim?
- nerdshoe 9y ago
  Legionnaire's disease thrives in air conditioners https://en.wikipedia.org/wiki/Legionnaires%27_disease https://en.wikipedia.org/wiki/Legionnaires%27_disease
  - LeifCarrotson 9y ago
    There's little risk of disease (Specifically, Legionnaires') from residential air-cooled A/C systems. The risk is typically from industrial air conditioning systems which use a water-based heat exchanger between a radiator system on the roof and the condenser. The water in this system is kept warm. The water in the condensate tray of a typical AC is cold and continually drained, so the disease doesn't propagate well.

jaboutboul 9y ago

Odd that no one here has made any comments on the correlation of the massive boom in air conditioning in the last 30 years around the world and climate change. Wouldn't it seem like having an ever increasing number of these things, humming constantly in both hemispheres all throughout the year and generating loads of hot air and greenhouse gases, is a significant contributor (even maybe main contributor) to the global rise in temperature?

btbuildem 9y ago
That, and they insulate us from the effects of climate change. Out of sight, out of mind, right?

robg 9y ago

Surprised the word "sleep" doesn't appear in the article. Sleeping well is what best prepares us for productivity the following day. https://www.nytimes.com/2017/05/26/climate/global-warming-sleep-loss.html https://www.nytimes.com/2017/05/26/climate/global-warming-sl...

rudedogg 9y ago

I live in an area where evaporative coolers are effective. I hate setting it up every year, and was looking into central air. When researching I learned about how efficient evaporative coolers are, and it gave me more appreciation for them. https://en.wikipedia.org/wiki/Evaporative_cooler https://en.wikipedia.org/wiki/Evaporative_cooler: * Estimated cost of operation is 1/8 that of refrigerated air conditioning It's really interesting to think about the advantages/disadvantages of geography in regards to power generation/consumption. It didn't really occur to me until going through the above experience. ---------------- The design of these systems is really interesting. Most of them have a lot of wearable parts (belt and bearings), which means more maintenance. There are some new designs (http://www.bonaire-usa.com/products.html#window http://www.bonaire-usa.com/products.html#window) that do away with the "squirrel cage" fan (https://en.wikipedia.org/wiki/Centrifugal_fan https://en.wikipedia.org/wiki/Centrifugal_fan), and a lot of the maintenance. I wonder if the efficiency of the new design is lower than the traditional centrifugal fan design? I know this can be found - I just don't want to go too deep researching. If anyone knows off hand I'd appreciate an answer!

humanrebar 9y ago
> It's really interesting to think about the advantages/disadvantages of geography in regards to power generation/consumption. I've seen air conditioning that amounted to basically a shaft into a natural underground cave and a fan. I've also heard of people watering the roofs of their houses in the summer to get low-tech just-in-time evaporative cooling for their attics.
- rudedogg 9y ago
  The cave thing is neat - sounds like an easy form of https://en.wikipedia.org/wiki/Geothermal_heating https://en.wikipedia.org/wiki/Geothermal_heating
cr0sh 9y ago
> I wonder if the efficiency of the new design is lower than the traditional centrifugal fan design? It depends. They each have their pros and cons: https://en.wikipedia.org/wiki/Centrifugal_fan https://en.wikipedia.org/wiki/Centrifugal_fan http://www.pelonistechnologies.com/blog/axial-vs.-centrifugal-fans http://www.pelonistechnologies.com/blog/axial-vs.-centrifuga... (might be somewhat biased) https://en.wikipedia.org/wiki/Fan_(machine) https://en.wikipedia.org/wiki/Fan_(machine) Unfortunately I couldn't find anything on axial fan efficiency or whatnot, compared to centrifugal fans. In general, though, if I had to pick one I'd go with the centrifugal fan for cooling purposes; they seem to move air much better than axial fans. They do make direct-drive centrifugal fans, but I am not sure if they exist in large versions for home cooling systems. They are made for use in computers, as well as for smaller (but still large) units like blowers for drying and for things like "air curtains" and smaller blowers for small air-conditioning systems.

setgree 9y ago

I thought -- this is a very pro-capitalist piece for the BBC! And then saw the byline :)

triangleman 9y ago

Not mentioned in the article: Air conditioning makes it possible to stay indoors, away from mosquitoes, thus fighting illnesses like malaria and zika.

iamthepieman 9y ago

From the OP "Historically, a cool building in a hot climate implied thick walls, high ceilings, balconies, courtyards and windows facing away from the sun." New Orleans is one of the clearest examples of this hot and humid specific architecture[0]. In that picture the second floor balcony represents roughly the height of the 1st floor ceiling. The many doors like porticos, can be opened on the shaded side of the building allowing for air flow. You see this style all over the city. Apart from reflective coatings on glass in high rises and office buildings and the occasional Leed certified building trying to save on energy usage, you don't see much architectural consideration for the climate. This is especially true in office buildings (in the U.S. anyways) built 1900-1950 or so with blocky brick buildings in which the central rooms have little natural ventilation[1] [0]https://www.google.com/maps/@29.9459548,-90.0658908,3a,75y,269.21h,85.25t/data=!3m6!1e1!3m4!1shFaAE9ft5lzkP8_FWgB0XA!2e0!7i13312!8i6656 https://www.google.com/maps/@29.9459548,-90.0658908,3a,75y,2... [1] http://forgotten-ny.com/wp-content/uploads/2005/01/e149stbusher1.jpg http://forgotten-ny.com/wp-content/uploads/2005/01/e149stbus...