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."
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.
I wish we had that rule. My last 3 jobs have been in historical buildings. One didn't have AC, and the other two have barely had functional AC.
My desk reaches about 80 degrees once the weather is over 65, and it won't drop below that until the fall. In order to make our AC more efficient they "weather sealed" the windows, which mostly involved gluing them shut. So now I can't open the window when it's cooler outside.
I'm sitting at my desk with my sleeves and pant legs rolled up like a five year old pretending to be a pirate. Most of the women don't mind because they can wear light dresses and slip on shoes.
The did give me a fan after I asked HR if I could wear women's clothing to work.
But seriously, it's kind of ridiculous to be paying to cool a place to a certain temperature when literally nobody in the office has any reason to be dressed up.
That article was far more sensible and pertinent than I was expecting. Especially relevant, given the fact that a couple weeks ago one of my coworkers was wearing a jacket while I was sweating though my clothes.
Our handbook is pretty terrible to both sexes though. There's two full pages on how women should do their makeup. It can basically be summed up as "You need to wear makeup, but don't look like a whore." So, at least I don't have to deal with that.
Honestly, I wouldn't complain if it didn't affect my work, but when it gets this hot I get dizzy unless I drink water like it is going out of style, which means I have to get up to fill my water and relieve myself. And even then I can barely concentrate.
I still blame the dress code more than anything. I'm comfortable to above 90 degrees or so if I'm wearing shorts and a lightweight tee. Slacks, leather shoes and a long sleeve shirt are not suitable much above 75 as far as I'm concerned.
I am not comfortable in temperatures above 80 in any clothing bar undergarments, especially not if you want me to be productive cognitively in any way.
And if you add humidity on top of that, it essentially reduces me to a vegetable, unable to do anything but take short naps and cold showers every few hours.
I definitely feel that way if I'm in the sun with no breeze. I'm pretty tall and lanky though, and I sweat a lot, so I think the two of those things together combine to keep me fairly cool.
Being hot is definitely tiring though. I'm pretty sure I use a ton of energy just sitting around sweating, and if I have to walk anywhere in that weather I'll just want to take a nap when I get there.
South Korea started following the same policy a few years ago. The thermostat is set at 28C in most offices, and people care less than they did before about men wearing short sleeves and no ties.
One problem is that Seoul is further north than Tokyo, so the temperature tends to stay around 28C anyway, especially during the monsoon between mid-June and mid-July. Thermostats only detect temperature, not humidity. So the A/C sits idle and everything gets damp :(
> 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.
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.
Decreasing the AC doesn't mean people will start sweating themselves. 75 - 78 F is perfect but most buildings for some reason turn their ACs all the way down to the 60s.
For athletic centers, of course it makes sense. But in big open libraries, lecture halls, places with little activity in general, it's awful. It's especially bad for your health if you live in a hot region like southern California since your body has to keep adjusting between the scorching heat outside to the freezing cold inside.
I suspect it very much depends what you are used to - I probably think of 15C as "comfortable" and 25C inside would be sweltering. Having said that I'm in Scotland - the other day we had heavy rain and it was 8C which is weather we could get at any time of the year!
Maybe I'm being dense and saying the same thing as you, but it's more about the difference from outside to inside. In the mid Atlantic of the US, 22C can be pretty pleasant, but in the South turning it below 26C is a much more pleasant setting. Meanwhile, spend time in Southern China and you'll be laughed at for going below 30C, because it makes you nearly unable to go outside. If I feel like the humidity outside is going to condense on me when I take the dog out, I'm cooling my house too aggressively.
Similarly, I don't heat above 15C in the winter. That way, getting dressed to go outside is less complex than suiting up for a space walk.
I must admit that I don't know the difference in temperature from inside to outside - for half of the year (say May to October) we don't have heating on and we don't even have air conditioning (I don't know anyone who has air conditioning at home in Scotland).
The main difference I'd see between inside and outside is the lack of rain and wind in the former - temperature difference is secondary.
What closing do you use at 15C? After a few years in Norway I can be OK in a t-shirt at 18C. Anything below that still requires a jacket or sweater to stay comfortable.
Not OP, but here in Austria I wear t-shirts for most of the year. I even used to go out in just a shirt on warmer winter days with only light snowfall, but nowadays I really notice the cold when I do that. Everything above 10°C is very comfortable to me.
Among my friends and relatives I am the exception of course. Most of them dress in more layers, some even in summer.
I suspect its because we used to live in a very old property that was very difficult to heat. So we got used to it!
Edit: I remember going to the halls at Uni for the first time and nearly dying of the heat - never lived anywhere that had central heating. Got used to and, of course, felt like I'd been exiled to Siberia when I went to my parents ramshackle large house for the Xmas break.
Wow. I think of 15C as "comfortable if I'm outside doing stuff and wearing long sleeves", but inside, it's "put the heat on (to 18C) and put on a sweater". 25C inside is what we set the air conditioning to in the summer at night so it's easier to go to sleep, but in the day, 26.5 is fine. This is in the southeastern US, and I've converted all temperatures from how I normally think of them in F.
Also, my workplace keeps inside air conditioning much cooler than I would, around 20C, which is uncomfortably cold when I'm dressed for the summer weather (ranges from 27C to 38C).
In my department at my university, professors and staff usually end up bringing a sweater and leaving it in the office so they have it in the summer. It gets kind of cold in the offices.
I've set my apartment to 26C. I find that without the humidity (since the AC deals with that too), 26C is actually not too bad for the summer.
After moving from Phoenix to the Seattle area, I've noticed the 'feels like' temperature is about 11C difference. 30C in Phoenix feels like 19C in Seattle.
It seems to be common practice here in northern Bavaria to only cool offices to about 5 C below outside temp - so if it's 35 C (95 F) outside, only cooling to 30 (86 F).
Fortunately, wearing shorts to work on extremely hot (over 30 C) days is also more socially acceptable here.
It once was in NZ too even in formal environments - we called them "walk shorts" https://en.wikipedia.org/wiki/Walk_shorts - but they are now derided as an historic "fashion crime".
You acclimatize. I'm from chilly Sweden and used to start wearing T-shirts when it hit 18 C. Right now it's 27 C and I'm actually feeling a bit chilly (it was 29 C yesterday). Summers reach 36 C with high humidity.
I recall reading (no ref) that nazi experiments determined the optimal temperature for mental performance was 59F, which coincidentally is the average temperature of the earth.
I went to school in Northern Wisconsin, and we had a bunch of people from the Caribbean living in my dorm freshman year. There was one thermostat that controlled steam delivery for each floor of the building, and then the radiators in each room did their own thing.
The people from the Caribbean would turn the heat up to 80 degrees all of the time. It got to the point where the thermostats were pulled off the wall in the middle of the night by to keep them from being turned up.
I think probably 3/4 of the building had their windows open all winter, even when it was -20 below outside, just to keep the temp livable. The thing is that it doesn't do much with steam heat, since those radiators can pump out more heat than you can possibly imagine.
The physical plant ended up putting the thermostat within a metal box that was grouted to the wall.
I can understand though. The first time it hits 40 degrees after the summer, I'm freezing, but if it hits 40 in January I'm walking around with shorts on. It was still kind of funny to listen to them describe what being really cold is like: "I'm on fire! Why do I feel like I'm on fire from being cold!"
I'm sure I sound equally hilarious when I'm somewhere hot though.
We're talking about nazi experiments. I'd assume that the "for Germans" part is implied.
"Caucasians" also seems the wrong abstraction here in either case. If you put a Swede or Brit and a Spaniard or Italian in the same room, they'll likely have different opinions the optimal temperature too, yet all of these are pointlessly grouped as "Caucasian" just because some people like to pretend it sounds less racist than simply saying "white" (which is an equally useless category for most concerns).
I grew up in a pretty cool climate (Maine). Above 65 I begin sweating. Especially if the humidity is above 60%. 58 is ideal working weather as long as the humidity is low. 35-45 is ideal sleeping weather, with window cracked open so to allow a breeze to counter at the heat from the stove.
They may have the issue of only having one thermostat for the whole building. They then have to balance the demands of the people in the coldest part of the building and those in the warmest part of the building. If the system isn't well designed, those could be tricky to reconcile.
We researched this and it seems like the 'optimal' temperature for office workers in warmer climates is 23-24 C or 73-75 F. In the winter your office temp should go down slightly to compensate for people wearing thicker clothes.
It depends on the climate. I used to live up north and we kept our houses and buildings around 68-71.
I live in a hot climate now and it's normal to keep inside temps 75-78.
In both places inside temps feel normal. The body seems to adjust it's idea of a comfortable temperature after acclimating to a new climate. When I first moved down south I kept my thermostat at 70 but it felt too cold after a few months. My most comfortable temperature is 76 now.
Even though I live in very warm/mild weather area, I ALWAYS try to keep a jacket handy if I know I will be going into an enclosed place to be sitting still, like theaters, restaurant, etc.
It's really silly that we have the technology of AC but cannot control the temperature accurately enough.
Yep, in the southeastern US it's routinely so cold inside that were it to get that cold in the winter, they would turn up the heat. Except that instead of wearing three layers of clothing you're in shorts and a T-shirt because it's 95F/35C+ and 100% humidity outside.
I don't think I'll ever get used to this. I don't see how it's possible even in principle to acclimate to such large swings in temperature over such a short time frame.
As a person from northeastern Europe living in Tokyo, I really hate the Japanese doing something similar -- in the summer they set their ACs to 20-22, when it's 35 outside, while in the winter everywhere inside is at 25+, quite often even as high as 28. Plus, their ACs are the 'blow freezing wind in the face' type, so it's extremely terrible for the health. I have taken to wearing a quilt+buff for the neck during the summer just to avoid getting sick all the time.
At least I sit next to a window, so I can let some warmer/cooler and fresher air to compensate, but it is such a waste of electricity, it drives me nuts.. It's also imposible to concentrate when the air gets too dry from the AC.
Humor aside, there's a point for me at which even with more clothes the AC is too cold or aggressive and I end up with headaches. Fortunately I am aware of it and I try to be preventive about it (by moving away from the thing).
Seriously though, I live without AC at home (Portland, OR, so not a real hardship) and often wear a cap and vest during the winter. I kinda like having more connection to the outside temperature.
As someone who has lived and spent a lot of time in both very humid and hot areas, like South America and the Southeastern US, and as someone who has also lived in the PNW... I have to say, you simply need to accept that you simply don't know what humidity is in the PNW... heat too, and just weather in general (haha, people in seattle had a meltdown when it hailed).
Sure, it's more humid, than, say, San Diego, but it's not humid in the PNW, by any rational means.
There's a reason AC is uncommon up there, because it's really not necessary.
As for heating, that's more of a concern up there, and that's why oil heating is WAY more common there, than, say, Alabama. The opposite is true for cooling, too...
But, as someone else who lived in the PNW, I have to agree with you at least on one front, some good fingerless gloves are basically necessary in the winter.
You can't take off your skin, but humans are adaptable. My family has minimal problems sleeping in 80/90 degree rooms, though we prefer high-60s.
I suspect (for offices) it has to do with productivity - warmer people can get sleepy after lunch, etc. Colder people are more alert (to a certain point).
My office space in china would keep the temperature around 24-26C in the summer. My arms would literally sweat to the desk when typing (I'm not a completely in the air tyoer, as a programmer I don't need to be). I had to hit a cooler Starbucks with a laptop to get things done it was so annoying. I much would have preferred it being a bit colder, around 20C is best, even if I would wear a light jacket at that temp...at least I could type.
It sounds very weird. If the space is closed, the AC makes the air dryer, so sweating should be minimal on these low temperatures (dampness is hell).
Are you sitting next to a window that is blasting its rays over your body?
Is the building badly designed?
Are you protected by a layer of fat cells?
Sweating at 24-26C without sunlight blasting at you is very anomalous.
Lowering the AC to 20C or below is such an insanely wasteful thing to do it ought to be forbidden. The biggest CO2 footprint is us, the first world, heating and cooling.
As someone that lives in the UK, 24-26C is where you would find me in a T-shirt and shorts and probably still feeling warm. Any physical or mental exertion will probably lead to a bit of sweating.
21 degrees is what I would consider a 'normal' room temperature, anything above 23 I would consider 'warm'.
I don't disagree with you but I'm not sure all your questions are reasonable/respectful. Here are a few examples from my situation.
The AC in Japan has two settings--one is cool and one is "dry" for dehumidify. The cool setting does not dry the air (or if so, ever so slightly). We have high humidity so 26 degrees can feel hot indoors.
There are some seats in the office that are close enough to have the sunlight hit the desk. I'm not in one of those seats but can imagine it feels very hot.
Our office is "set" to 25 but at my desk it is often over 28 degrees (all the towers are on the tables and the AC is far from my location). I consider myself in fairly good shape but sweat quite a lot when it's over 28 degrees with a PC tower blowing hot air at me.
> The AC in Japan has two settings--one is cool and one is "dry" for dehumidify. The cool setting does not dry the air (or if so, ever so slightly). We have high humidity so 26 degrees can feel hot indoors.
I'm curious how this works. In America, we have only one setting, and it does both. The indoor air is 23 degrees or so (22 in busy offices, 25 in frugal/environmentally conscious homes...28 would be considered oppressive heat, no matter the humidity). But the evaporator coils in the air handler should be cooled to about 5 degrees in a properly functioning air conditioner. If the air is humid when it cools on these coils, it drops below the dew point, and humidity condenses out of the air to be drained out of the building. If the AC is properly sized, it keeps the air indoors comfortably dehumidified (if too large, it will cool a small amount of air by a lot, and run too infrequently to dehumidify; if too small, the air temperature will not drop enough to cause condensation).
We also have dehumidifiers, which are practically identical to air conditioners but have the condenser coils in the same machine to warm the air back up before it exits (and to simplify construction/improve efficiency). These actually add a bit of heat to the room, but do dry out the air. Typically, these are only used when a home doesn't have an air conditioner.
The office HVAC was one of those new green energy efficient one. It didn't seem to extract humidity as well at higher temps. I complained about the humidity level, but it was easier just to move to a cafe with decent AC.
I wasn't sweating heavily, or any at all, just my arms were sticky to the desk. It was warm enough that long sleeves were out of the question, so contact was unavoidable. Also, my desk was next to a window facing east, and our blinds were a bit tricky to raise and lower (decide between, darkness and heat filtering).
It is easier to deal with 26C as a baseline temperature in LA than BJ given that humidity is much lower in the former.
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.
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 :-)
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.
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.
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.
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.
> 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.
Fellow Zoni here, and a moon-lighting HVAC service tech. To clarify a common misconception, A/C refrigerant does not cool air even though that is the net result. It actually absorbs heat and releases it outside the strucure. Sorry for the pedantry, but if we come here to learn, may as well learn the technicals.
This is a distinction without a difference. Removing heat from the interior air is the same thing as cooling the interior air.
If you mean that the air conditioner doesn't produce a magical substance called "cool", that's true, but no one claimed that it does. The mechanism transfers heat with the effect of cooling the interior.
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.
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.
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.
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!
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).
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).
Spare a thought for the Philippines - the wikipedia typhoon path picture almost completely covers the entire country (HK is hidden in there too, though)
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.
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.
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.
> 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.
> 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.
> 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.
I wonder why central cooling hasn't taken off like central heating has. It seems to me that the economy of scale would work really well with cold just as it does with heat.
Compressed liquid refrigerant is very expensive compared to cheap water for heating. Long pipes full of liquid would be very expensive to initially fill not to mention after leaks. And there would be leaks...
Historically most refrigerants have had "issues" when leaked either environmental or being toxic or otherwise it minimizes danger to keep as little as possible. Even if we could afford to use 1000x as much refrigerant with a central compressor station, it would be bad for the environment to use it that way.
You can move a huge amount of heat with water pressurized to merely 14 psi or so, but I have a puron aka R-410A conditioner at home and that dude runs near 400 psi on a hot day and its difficult to run miles of high pressure pipe.
I'm not sure bigger compressors are that much more efficient than smaller compressors, taking into account the environmental and economic expense of the pipes.
From an engineering standpoint its cheaper safer and less environmentally destructive to push kilowatts thru copper wire than push high pressure expensive refrigerant thru long high pressure pipes if all other things were equal which they mostly are.
You do not have to distribute the compressor gasses- you just pump cold water/glycol around. Every factory everywhere does it this way for distributed cooling, as well as hospitals/colleges/corp campuses with central plants.
Why would you need to use the refrigerant itself for heat transfer from end users? Couldn't you just use water for that; like they do for central heating? (E.g. Chill water using centralized AC, then pump the cold water through pipes to cool homes and businesses?)
Why would you use long pipes of refrigerant? Move the air, not the refrigerant. Plenty of existing central heating systems do that (no radiators, just vents in each room). Systems like this already exist and work rather well.
In the US, centralized AC is the norm in the numerous suburban houses. Newer apartment buildings in cities have centralized AC and window units are usually only used in older buildings.
You are speaking centralized as in having one central unit for the building, are you not? I am speaking about having a big company, usually city-run, making the cool in a huge plant and then pump it out (in insulated pipes) to the rest of the city/town.
The heat version of it is very common here in Sweden (for towns bigger than, say, 10k people) and it is a lot more efficient (and therefore, cheaper) than having heating units in the different buildings. We even have bigger data centers selling their spare heat from their cooling back to the heating systems.
Universities often have one or more chiller plants that cool multiple buildings on campus (also boiler plants).
Very large building-sized boiler and chiller plants served each half of my campus (probably less than a square mile in total). I'm not sure it would work at city scale.
I live in a building that does use central cooling. I'm not quite sure how it works, but I believe that they pump chilled water through our radiators. The radiators are more like air conditioner radiators than traditional cast iron radiators, and they have fans attached that can be controlled by the renter.
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.
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.
I guess it is a progression where people learn from the problems they had before.
Step 1: It is too hot/cold here
Step 2: Lets put in heating/AC
Step 3: Damn, the electric costs are getting too high. Lets put in insulation and double-pane windows (well, actually three-pane is standard here in Sweden) to keep down the costs.
The further you live to extreme heat or cold the faster a society progress down the ladder. Which is also a reason the death rates during winter is a lot higher (per capita) in central Europe than it is in northern Europe - people in the northern parts have long since been forced to learn to build better houses whereas people in mild climates can afford to fail as it isn't that many days a year that it is a problem.
Have any part of Texas considered central cooling? It should be even more effective than having units in every house as long as it isn't too damp and the water needs to be removed as well. But perhaps that kind of solution would be too socialistic for you :P
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
"houses are now built with very little regard to insulation"
I find that hard to believe. Where I live the local muni delegates to a state wide "uniform dwelling building code" I googled it for laughs and the minimum ceiling insulation as of the '09 revision was R-49 which is about 14 inches of fiberglass.
My concrete block basement walls met code 50 years ago at about R-2 insulation value, as of '09 the mandatory minimum for new basement walls is R-15, OK then..
The biggest problem I see with post-AC era houses like mine is very poor cross ventilation. I must run the AC when its 60 degrees outside because the windows are not oriented for cross ventilation so I will roast alive at 85 degrees indoors when its 60 outside without AC.
Central house fan my friend. Not too difficult to install if you're comfortable cutting sheetrock and doing a minimal amount of wiring. Run it for 15 minutes and you'll have your house cooled down considerably.
I do agree that having the house designed for good airflow in the first place would be ideal.
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.
Where was your house built where energy wasn't a concern? In the US, nearly all regions will get a cold winter or a really hot summer and nobody likes $300/mo utility bills so efficiency is still a concern.
It's not where, but when. I worked with a very knowledgeable realtor a few years ago when buying my house. He described (and we observed) a series of trends.
Older houses (in my area, that's early 1900s, laugh away you European readers) were built with huge beams of old-growth timber by careful craftsmen (sometimes in the Craftsman style, sometimes colonial or victorian). Houses this old typically had antique plumbing and electrical service, which needed (or now really need) upgrades, and they also will likely need window and/or siding replacement. During these repairs and remodels, smart homeowners and contractors also upgrade the energy efficiency, and there's a very strong skeleton on which to do so.
Shortly after WWII, there was a lumber shortage. You can drive around and identify the neighborhoods which were constructed in the late 40s and early 50s because the eaves only project a few inches out from the walls. These were built as fast and cheaply as possible. But for a while, energy - especially for heat - was cheap, so they kept building them.
Since then, energy has become variously more and less expensive, and manufacturing/construction techniques have produced cycles of lower quality cookie-cutter cost-optimized goods and higher-quality standardized, well engineered construction. We're riding high on an efficiency swing right now, to the point of absurdities like homes so well air-sealed between Tyvek, caulk, and air-tight electrical fixtures that you're required to install an air vent to the outdoors in the furnace room to prevent negative pressure problems.
That's what surprises me about Australia. The place can get bloody hot and yet Aussies usually stay in buildings with no thought for insulation at all.
Yeah, mostly by using crazy amounts of air conditioning and heating. It's pretty terrible. The standards for new homes are getting better, but they could go much further.
"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."
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!
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.
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.
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.
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).
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.
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.
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.
My office in 2015 was in an Altbau with very high ceilings and thick walls & it was nice and cool. I would still argue in favour of better insulation/construction.
EDIT: oh but transit here should definitely be better air-conditioned: I don't think there's much you can otherwise do to make subways/trains/busses pleasant once it starts getting hot.
I remember I returned from my parents where I had stayed over the weekend and it was okay - to a city that was still glowing from the heat at 11 pm at night. I say that as someone who spent a summer vacation in the Emirates (that place has cooled swimming pools right at the beaches, and for good reason the Gulf water is not warm but unbearably hot!).
In general, if/when global warming picks up we have to make some major changes to all our cities. As they are now they are giant furnaces and heat batteries with all the exposed concrete and asphalt.
Southern china is really cold in winter for the same reason: no heat, no insulation. If you heat your apartment, you have to heat all your neighbors, so the only solution is a kokatsu. North of the Yangtze is much better because the central government has dictated that those cities get heat.
In HK, a few hundred people always die when it dips below 10C.
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.
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.
It seems nobody has mentioned a near-epidemic of respiratory system infections caused by air-conditioning. And I do not mean the cases where A/C is infected with some rare bacteria (e.g. Legionella) often causing death. Usually it is just common cold or sinusitis caused by overly chilled and dry air. I wonder what are the health-related costs of overusing A/C in moderate climate.
The dew point in my house in August when the AC is running continuously is in the 50F to 60F range. The dew point is around 50F outdoors for a couple months before and after August.
The dew point in January during a cold snap spends weeks around -20F. This is fairly self evident, we have some crisp dry snow free mornings around -10 to -20 every winter and obviously if the dew point were above -20 it would be snowing at that time, or at least cloudy. If I try to humidify the house it'll just get moldy so I let it dry out instead.
I have noticed my hands get dry skin problems, skin cracks and gets infected, when the dew point is below freezing for a couple weeks. Winter is a bad time for static sensitive electronic experimentation. I participate in many winter sports activities and when the dew point is -20F you don't have to sweat much to get hypothermia or dehydrated. Dehydration is a big problem for long distance hikers in the winter, you have to carry the water in a thermos or it'll freeze and tradition is to drink caffeinated hot beverages which makes you pee which dehydrates you faster than not drinking at all.
You'd have to live in an interesting climate where the dew point in the winter is higher than the dew point in an air conditioned house in the summer.
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.
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.
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.
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.
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.
* 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.
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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) that do away with the "squirrel cage" 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!
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.
"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]
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.
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
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.
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?
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.
> 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?
I get what you are saying and I'm not anywhere near as informed as you are. Although I did see some lab tests that did show a change in the bacterial environment after using the spray and the fact that it works for me, personally. I spray some in my car and bedroom as well.
I cant give a name though; I just bought a box of 'samples' from a guy that's doing some research with it. But it's years away from market, judging from his story. Could send you a 20ml spray if you'd like. :)
As to your 2nd point, go find your indoor blower(furnace closet for split system or outside in a package unit), pull the power supply, then open and take a look inside at the blower wheel. Unless the unit is a less than a year old you will will clearly observe why health risks do exist. If you need more proof see the evap coil & the primordial sludge in the condensate tray/drain. When finished, reassemble, plug power back in & change your air filter.
I clean out my evap coils and condenser coils annually, and replace my filter twice a year (for efficiency, not for health). I'm well aware of the dust that my filter removes, which makes my indoor air cleaner than outdoor air. My allergen-sensitive wife proves experimentally that it has a strong positive effect for a couple weeks every spring and fall. And I'm aware of the crud that develops in the condensate tray. There's little crud in my central air system, but when I used a window AC in an apartment and the unit wasn't leveled properly it got pretty bad.
More generally, though, the presence of unattractive substances does not imply a health risk. My yard is, in the most basic sense, an enormous pile of dust, plus a few organics that grow and decay into dust. My home happens to be a few hundred meters from a lovely trout stream, and that stream and its floodplain contain more life from bacteria to algae to fish than any primordial sludge ever had. Neither are dangerous.
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.
The common cold is caused by a virus, not by bacteria. You can get the bacteria that cause Legionnaire's disease building up in the fluid in air conditioning units and then getting vaporized into the air, but I don't see how spraying more bacteria around is going to stop you from breathing in the ones the AC is blowing into your face.
I'd be very curious about which bacteria you have in your spray, and which bacteria they're supposed to be displacing.
That's a problem with your AC unit's poor antibacterial filtration and your home's filters. Filters should be replaced every few months, if not monthly. There's also UV lamps that can be installed in AC's, or units that come with them, to sterilize the coil and air.
https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew...