Lee | Air conditioning. 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.
You can get away with no A/C a lot easier if you're almost in the Arctic circle. In reality I bet this rule has a fairly minimal impact on energy consumption because the buildings didn't need much air conditioning to start with.
It’s possible to build buildings that are reasonably comfortable in high heat. It just costs more than a generic box with AC.
I honestly find working to be harder in that environment. German summers are traditionally not that long, but still it's two months of lower productivity.
There is one benefit though, shorts and sandals is accepted as office clothing.
I live in a country that uses traditional brick and mortar construction and I can tell you that American homes are far easier to condition climatically.
(though I couldn't get it exactly right on streetview)
In some cases A/C literally makes normal functioning possible, and is thus a boon to society and opens the argument to what level of environmental costs are worth it.
In other cases, A/C allows someone to not have to change to lighter clothes to be comfortable, or they have poor insulation and thus have to use A/C far more than they otherwise would. In these cases there is much less argument that A/C is worth the environmental impacts.
Exploring the difference is valuable - instead of arguing "Good/Bad", we can start arguing "How can we make things better?". Reducing unneeded A/C is just a good idea, and admitting that A/C has environmental impacts does not mean we have to instantly ban it.
We shouldn't compare A/C against heating because there's no value in knowing if one is "better" - we need both. We should instead act to reduce unneeded A/C use _and_ unneeded heating use (and to keep, if improve, needed uses).
I don't see how this could have developed from business wear.
Source for this?
And you need heating non-stop in winter, while in the summer half of the day is enough many times.
Also, most people have heating, but only some AC.
http://iopscience.iop.org/article/10.1088/1748-9326/8/1/0140...
So why speculate and not use data instead?
Look at your bills and use the price of kilowatt of electricity and the price of CCF or MCF of natural gas to calculate the cost of MBTU. The above study came to a conclusion that you will use 3.5 MBTUs in MN for each 1 MBTU spent in FL.
In my case 1 kWt cost ~10c, 1 MCF of natural gas costs ~$12. At these prices 15 SEER AC will require ~$6.67 for 1 MBTU of cooling 95% Efficient Nat gas furnace will require ~$12.63 for 1 MBTU of heating.
Can you do the rest of the math?
I usually drink 4-6 litres of tap water while at work, and I have to use a personal heater at my desk to keep warm in winter (my co-workers complain if I set the thermostat higher). When it's summer, especially when it's 35+ degrees (95 F), I'm in heaven.
In fact, the coldest I've ever felt in my life (and I've lived in cold places like Moscow) was the one time as a silly freshman in college, when I drank just under a gallon of water (couldn't quite finish it) in under a minute on a dare. So very cold, and nothing could warm me up. Just had to wait it out.
Water drinking contests, along with overhydration during/after intense physical exertion (e.g. marathons, partying on MDMA), account for nearly all known cases of death from water intoxication.
Or weave sealed cells of a phase-change material with high thermal mass that melts at around 33 degC into your fabric, and freeze the garment before wearing it. This makes possible a thick, heavy jacket that you can wear to keep cool.
I suppose the vapor pressure could be lower than that for water, if there were effectively none in the air already. That would only be more effective than sweat on very humid days. You would be wetting your wet bulb with two different liquids.
The trick is to find one better than water that is also non-toxic, non-flammable, non-carcinogenic, and non-polluting. It would almost be easier to just remove all that water from the surrounding humid air, so that sweating works to cool you down again....
The phase-change material between liquid and solid would work better, but still requires a separate cooling technology to "recharge" it. And phase-change material still works better in building walls than in clothing. So you're right back to keeping your whole building cool, rather than a specific person.
You could also strap a personal radiator to your back, but no one wants to work on the tropical plantation in the first place, much less do it inside spacesuit-like apparel.
Can you recommend one suitable for regular use?
There are a few liquids that would work. One example is the refrigerant HCFC-124. However, all of these liquids are chlorofluorocarbons, and cause much more damage to the atmosphere than any amount of A/C usage. Pretty much all volatile organic compounds fall into at least one of three categories: flammable, toxic, highly potent greenhouse gas.
For instance, you wouldn't want to smell like a ton of bananas all the time, or drive honeybees into a frenzy every time you pass by.
So if you are cooling a house to 70 degrees in 90 degree weather, you are fighting a 20 degree difference.
If you are heating a house to 70 degrees in 30 degree weather, you are fighting a 40 degree difference.
In a severe heatwave, you might spend weeks with much of the day at 100 degrees; during a cold snap last winter, there was a span where I live where the temperature was usually around 0, and never higher than 10 degrees.
Meanwhile, a furnace works by directly converting energy to heat; for simplicity, let's assume a heater generates 1 unit of heat for 1 unit of energy (it's 100% efficient).
An air-conditioner, however, moves heat, moving heat from inside to outside. An air conditioner doesn't use 1 unit of energy to move 1 unit of heat; an air conditioner might move 3 units of heat using 1 unit of energy.
So putting the two together, it takes roughly 6 times as much energy to heat my house on the coldest days as it does to cool my house on the hottest days.
The full answer is a lot more complicated than that, because other things in houses are generating waste heat and you need to look at the deviations above and below your target temperature range over the full year and across many different places. Someone else has already posted a link to US energy usage showing that total energy spent on air conditioning is a fraction of that spent on heating, but from the above you should be able to get an intuitive feel for why that's so.
So run that system backwards for heating, and you would at only use twice the energy for heating. That said, you can typically cut your heating bill in half using ASHP, with it losing efficiency as the outside temperature decreases. It rarely goes below a COP of 1, so it makes sense to use in place of resistance heating.
However that assumes that you must use electricity for heating. Using wood for heating, you are using a renewable resource that is cheaper for every unit of heat you get.
Even then you have to be willing to keep the thermostat set at 55F/13C or the resistive heaters are going to kick in.
That is not to say gas isn't cheaper.
Be careful, you're angering the thermo gods! If that was true, I would simply use an air-conditioner to heat my house. Cool, the outside and move the heat inside. In reality, you have the efficiencies backwards. Cooling is more energy intensive than heating.
It's true, and people do. Install a heat pump, and save your traditional heat source for when it's sufficiently cold outside.
Gas heating is something like 90% efficient now.
People, stop. Downvoting doesn't change facts.
No, this is quite wrong. You're not taking into account generation and transmission losses. Gas heat is actually much more efficient than electrical resistance heating.
Plus, as others are saying, using energy to move heat from one place to another allows you to move more heat than you could generate just by converting the energy to heat.
There is no real world scenario in a place that has a beating season where the cost to the consumer is better with electricity versus gas or oil. Electric costs about 4x for whole house heating in my neck of the woods, and houses quote electric only heat sell at a discount.
My guess is that your evaluation of electric externalities doesn’t include the health impacts of burning coal, ecosystem damage due to hydroelectric or long term storage and other capital costs incurred by nuclear generation.
I guess I live an unreal life. All of my heating and cooling is electric. My bills are lower than anyone I've compared with and in every case I'm heating and cooling more square feet. The magic? Ground source heat pump. Several people tried to talk me out of it and I'm glad I didn't listen.
In my area, you need to drill deep wells for heat pumps to work. Our local branch library did it and it cost about $40k.
I have electric resistance as a backup to my heat pump, only because they wouldn't install it without it. It would cost so much to run I have the breakers turned off just so it can't be shocked by my bill.
Heat pumps have a higher EER, but also higher parasitic losses, which is the source of confusion on the whole thread.
It's like claiming that rockets are "more efficient" than cars because they move you faster.
Narrow interpretations of definitions to support a point don’t actually provide much useful insight to the topic being discussed, and are seen as distracting. So these non-useful comments are being downvoted to make them less visible. It is not an issue of whether they are technically correct.
You could probably make an interesting point about the electrical efficiency of heat pumps, or you could make a comment about terminology and explain that “technically” the correct term is X, but instead you chose to interpret a term in a way that contradicts the contextually obvious meaning and then base an argument on top of that.
"arrow interpretations of definitions to support a point don’t actually provide much useful insight to the topic being discussed, and are seen as distracting. So these non-useful comments are being downvoted to make them less visible. It is not an issue of whether they are technically correct."
Except, I'm not arguing for or against a "point", only that the terminology was wrong. But it does matter, because it leads to confusion, and if you stop to think about it for longer than it takes to jab at the downvote button, the reason why it matters is interesting.
It's not that people here are thinking about the subject carefully, they're just disagreeing reflexively.
> Heating via electrical resistance is 100% efficient. All energy goes into generating heat. There is no loss.
This sounds a bit coy, doesn’t it? It’s a bit suspicious that heat pumps are completely omitted from your comment, and it’s also a bit suspicious that explicit discussion about terminology is omitted, and instead the definitions are included as a presumption. Putting the main point of your argument into a presumption of the actual text of your argument is nothing short of poor form (i.e. rude) if done purposefully, and the rest of the argument built on top of these presuppositions is boring and uninformative.
If you can imagine a better approach, consider discussing the terminology and definitions directly, and then explaining why sloppy terminology can cause confusion. You have still not explained why the terminology is so important here. Instead, you’ve made the following statements:
> …if you stop to think about it for longer than it takes to jab at the downvote button, the reason why it matters is interesting.
> It's not that people here are thinking about the subject carefully, they're just disagreeing reflexively.
Consider whether these statements make claims about the internal thought processes of people who disagree with you, and whether making claims about how other people think will further whatever goals you have commenting on this site.
The problem is, the terminology is only wrong if you take an extremely narrow approach of "heating" being "generating heat". But it's quite obvious that we are discussing heating of an enclosed space. And it doesn't actually matter at all whether that heat being placed into the closed space was generated from raw energy within the enclosed space, or moved from externally into the enclosed space. And if there is no difference between these two options, you can achieve greater than 100% efficiency between energy-spent and heat-provided by moving the heat.
Voting isn't specifically for correctness/incorrectness, but encompasses many things. In this specific case, I think the voting reasoning or on your comments can be likely be summarized as "is the comment contributing usefully to the discussion, or providing useful or insightful information in some other way". I think people aren't viewing your comments in this discussion as providing that, and some people may believe they are actually the opposite.
And the bottom line is that for the same unit of energy used to generate 1 BTU from resistance heating, we can move several BTUs.
EDIT: I'd also like to note that heat pump systems which include resistance heating systems will typically mark them as "emergency heating". Because they are less efficient, unless it's so brutally cold outside that the heat pump has dropped below 1 EER or can't even operate properly.
EDIT2: I forgot that the units in SEER are not the same on both sides of the ratio. (That is, it's not actually a ratio, since those are supposed to be unitless.) So my original "13+ BTUs" was high. Changed it to a non-descript weasel-word instead.
I often find that it surprised people to realize that a heat pump is effectively >100% efficient.
It is nice to know that the conversion from electricity to heat is effectively 100% efficient and we are really making a cost comparison instead.
I know, that sounds crazy, and sometimes the CoP is given as an "efficiency", which makes it sound even crazier — a CoP of 2.0 is "200% efficient"! But it's not science fiction; it's a simple consequence of the Carnot cycle being reversible and the Carnot efficiency of heat engines at ordinary temperatures being quite low.
They use a lot of energy when they turn on initially, after that, its very little . Ive been working on smart thermostats that take advantage of this phenomenon to lower HVAC costs.
AFAIK, the most efficient residential systems are ductless split systems, where you basically have a centralized compressor and distributed air handlers in individual rooms. This allows for variable flow and localized control, which reduces need.
[0] https://en.wikipedia.org/wiki/Seasonal_energy_efficiency_rat...
> But when either replacing equipment, or specifying new installations, a variety of SEERs are available. For most applications, the minimum or near-minimum SEER units are most cost effective, but the longer the cooling seasons, the higher the electricity costs, and the longer the purchasers will own the systems, the more that incrementally higher SEER units are justified.
No you don't. I don't know anyone who leaves their heating on at night. In the winter I run my heating for a few hours a day maybe.
With the cost of fuel oil (common here) many people have installed supplemental heating in the form of heat pumps. The side benefit is they also have cooling capabilities.
My point, the local power company said in a news release power use during the summer took a big jump. But even with all the A/C units in use power use is still 20% lower than in winter, heating uses much more energy (and many people also supplement with wood).
In Calgary it's dark from 18:00 to 09:00 in December, but only from 23:00 to 05:30 in July.
If I remember correctly, the energy use of heating/cooling is related to the square of the temperature difference, so if ACs with a low temperature delta use nearly as much energy as heating does in winter, with its higher delta, it indicates that there may be a lot of waste.
It wouldn't take as much energy if people would close their windows.
And my dad leaves the AC on all day. I said just turn it on ten minutes before you go in the room it will probably do the same and be cheaper.
With AC you only move the heat, so spending 1 unit of energy you can move 2 or 3 units of heat. More, if the system is highly optimized.
With heating, you need to spend 1 unit of energy to create 1 unit of heat.
(Unless you heat with a heat pump. But even then, pumping heat for heating operates on less favourable temperature differences than pumping heat for AC.)
Modern split-system air conditioning units are just heat pumps, and often they are actually more efficient at heating than cooling. For example, Mitsubishi Electric units give out 4-5x the amount of heat vs amount of electricity put in. They will comfortably work at this efficiency down to around -15c (below that the efficiency reduces, but it's still higher than an electric radiator) so are suitable for most climates.
http://library.mitsubishielectric.co.uk/pdf/download_full/37...
I'm rather surprised they are't more common here in Northern Europe, where a lot of residential heating is powered by electricity. Compared to alternatives like storage heaters, they aren't that much more expensive. And you can use them in the summer for the occasional heat wave :)
There is almost no domestic air conditioning industry. On the rare occasions it gets too hot we open a window and thank the Gods. Thus there are very few cheap and reliable domestic suppliers of air conditioners for heating. And the air heating ones are tarnished by our experience with the unsuitable water heating ones.
So we burn oil/gas or electric storage heaters... Achieving a 300% efficiency and actually being able to heat a poorly insulated UK room just sounds too good to be true.
Sorry to be so negative. But that`s why so few of us have heat pumps... Its a shame, the air to air ones sound great on paper, much better than a £600 storage heater but I just can`t bring myself to trust them.
Intuitively heating should be cheaper, since loses are heat. Whereas with cooling you'll have inefficiency (e.g. in the pump) in the form of heat, therefore more energy to remove that additional heat.
A typical AC can take 1 kW of input power and remove ~3kW of heat energy from the room. The outdoor part of this system is heated by 4 kW, because you put the high-power stuff outside, where it's unimportant to performance. You can't thermondynamically make an AC work if it's purely in the room.
With resistive electric heating, you put in 1 kW of heat and the room temperature increases by 1 kW of heat energy.
With a heat pump in heating mode, you can put the inefficiency to use, using a 1 kW input to extract 3 kW of energy from, say, the ground, and putting 4 kW of energy into the room.
Two main problems with the argument: Cooling, as you say, is typically 30->25. Heating is often 0-25, requiring 5 times more energy (though we should be doing this in Kelvin...) Second, heating is super easy to do thermodynamically by just burning dirt-cheap natural gas. For a Michigan anecdote, I paid about $150/mo to keep my house cool in July, and it's typically $100 to keep my house warm in January.
If you do keep it in the same room, it's called a dehumidifier. :)
(And yes, that's why air put out by a dehumidifier is warmer.)
Could an AC that created matter from energy work?
This argument seems flawed. You don't cut the heat off every night and let things cool back to ambient. You maintain a stable temperature.
What the parent comment neglected to mention is the working temperature of the gas / fluid in the heat pump.
R410a boils at -48.5 degrees[1]. So based on the size of the system and some maths I couldn’t explain so I’ll hand wave away, there’s your answer. Sorry, that’s the best I can do, you’d have to read some Wikipedia entries to get a better understanding.
Modern heat pumps / AC can be up to 1:4.5 thermal efficiency, but it depends on the the temperature difference, the size of the system, and what you’ve got it set to.
Other places I’ve lived it gets to 48 degrees outside and you set the AC to 17 degreee because Australians are really bad at insulating their homes, so a 31 degree temperature difference, so in that sense the parent comment is flawed.
Also the sun will be adding some amount of heat during the day, which helps in the cold but makes the situation even worse in the heat.
We have two AC units in our home that are entirely inside, there is just a hose connecting the unit to the window and the hot air is blown through the hose.
The problem happens when there is a big difference in outside temperature. All of the gains of heat pumps disappear. So cooling from 25C inside to 20C inside when it's 30C outside might take 0.5 units of energy, which is a pretty common case. Heaters generally have to deal with much bigger swings, though. It's not uncommon to heat from 15C inside to 20C inside while the outside is at -10C, which takes (asymptotically approaching) 1.0 energy unit.
So the inefficiency of the A/C producing heat does matter, but not as much as the difference between the desired temperature and the outside temperature. The rate of heat transfer of the house also depends on the difference in temperature. Keeping a house 10C cooler than ambient takes less energy than keeping a house 20C hotter than ambient.
Considering that temperatures on Earth vary from about -90C to 50C, and humans like to keep indoor temps around 20C, cooling is generally more efficient than heating.
This gas is the refrigerant that the article refers to. Basically, what air conditioners, refrigerators, heat pumps, ect, do, is compress and expand the gas in a closed loop.
The whole theory behind a heat pump is that you get more heat, per unit of input energy, than if you used the input energy directly for heat. The consequence is that you end up blowing cold air outside.
throw in the added benefit of AC is humidity control and AC is just a win win tech.
Also, there's a lot less efficiency loss burning oil directly for heat, compared to burning oil for steam for 40% electricity which then gets turned into AC with some further efficiency loss. I expect the AC cooling might still come out on top, but not be nearly as much as implied.
I don’t know if it’s a stigma but it’s arguably a myth. Having lived both in areas where 40C is normal day after day in the summer and other areas where 0C (or below) is normal day after day in the winter, I can tell you which of heating and cooling is optional. In the extreme heat, as long as you drink enough water, you’re usually fine without air conditioning (but very uncomfortable). In extreme cold, blankets only go so far and you risk dying if the heat goes off. In my view one is definitely a luxury and the other is not.
Actually curious: is there anywhere on earth that the heat (by itself, assuming proper hydration) will kill you like the places on earth where the cold will kill you?
On the other hand wi yet 2015 was blamed on 40,000 deaths in the UK alone
On the other hand, you can forgoe heating by buying another thick blanket, keeping warm is relatively simple compared to keeping cool, notably because the human body naturally produces heat. All you need to do to keep warm is to prevent it from going away.
...and Houston which is further south and has a subtropical climate. It boomed in population after A/C became a standard thing.
> I think there is a stigma people have that heating is essential for life, but A/C is optional.
Yes, and A/C is a public health issue. In subtropical climates it keeps people indoors and away from disease carrying insects such as mosquitos.
Houston _is_ a hellhole part of the year. But ports are necessary and, while they needn't be cities, they usually are.
Two things about that:
- Regardless of climate, cities are too often built in regions that are prime river-bottom farmland. It would have been better if such lands were left for farming (since they flood easily and harbor disease) and the cities located at higher elevation.
Houston was built literally in a swamp. Part of this is it's use as a port city, but it didn't have to be that way. Thanks to storms and flooding the city is slowly moving to whatever higher ground there is (honestly there isn't much).
But as long as the government provides flood insurance at bargain rates, developers will build new homes in flood-prone areas and sell the homes to suckers who don't know any better. The developers sell out and move on to new projects, the homeowner gets flooded and the government(taxpayer) pays for the stupidity and inefficiency of it all.
- Houston's humidity is high, so the usual pressurized A/C system is required. Dallas in contrast has low humidity so that evaporative A/C systems, which are much cheaper to build and to operate, can be used very effectively:
http://www.air-conditioner-home.com/best-evaporative-cooler-...
We could argue, under the same logic of not building in Houston, that the Netherlands ought not be developed given their elevation.
I didn't say people shouldn't build in Houston. I proposed a framework under which the economic incentives would presumably provide improved signals about whether building/living in Houston was a better idea than doing so elsewhere: require developments built in areas that can make federal flood insurance claims to pay something into the risk pool. Developers and potential residents can decide if the rest is worth it.
Costs like plowing snow or risks like earthquakes and wildfire risks seem to be covered by local taxes and/or private insurance. If the savings Houston achieves from having no need for them really do outweigh the problems of flood risk -- as your comment seems to suggest -- then presumably Houston would remain an economically appealing place to live even after my proposed change.
Presumably the same thing happens with the Netherlands and the Dutch bear the economic costs knowing it's worth it.
Under current incentives, the positives of living in Houston certainly outweigh the negatives. Otherwise people would not live there. But were the externalities exposed and the costs shifted away from the taxpayers, then the population map would undoubtedly shift Northward.
Part of the problem is that most of Houston is near sea-level and flooding occurs where there is heavy rainfall, a random process. This problem exists for adjacent areas, out to San Antonio and Austin. Typical political response to flooding is to build a dam or holding reservoir, whereupon the next heavy rainfall occurs in an area above, below or away from the dam...build another dam/reservoir...rain falls somewhere else.... You get the idea.
Then there are hurricanes, their associated storm surge and flooding which simply overwhelm any dams/reservoirs.
The idiocy/malfunction of society vis-a-vis housing development and flood-prone regions is only one example of many such economic externalities:
https://www.houstonchronicle.com/business/article/Flood-Game...
What appeared to be a good idea intended to help a relatively small group of suffering people turns out to have been sponsored by a much smaller group of extremely greedy people (here, developers and insurance companies), all to the detriment of taxpayers (who weren't/aren't paying enough attention). Adam Smith's "invisible hand" once again spanks humanity's butt:
“People of the same trade seldom meet together, even for merriment and diversion, but the conversation ends in a conspiracy against the public, or in some contrivance to raise prices.”
- Adam Smith.
My mantra is "Flooding is Nature's way of telling you to move." regardless of whether you're speaking of storm surge in Houston or flash flooding in Utah. I see no reason to live in a region encircled/protected by a dam or seawall
And once you start attempting to dam off the sea, taxpayers never cease paying for it. There's a proper myth and a term for that - Sisyphean - although the phrase "spitting into the wind" (and variants) comes to mind also. BTW did you know that Galveston was once the largest port city in Texas? It was wiped out by the 1900 hurricane (6,000-12,000 dead) although people continue to live there today:
No, if we can all live without food. Plants love the hot parts of the world. The prairies bake in the summer.
I'm reminded of President Bush visiting the John Deere factory. He asked a worker about the most important innovation for combination harvesters. Without hesitation: "Enclosed cabs with air conditioning".
Then add all those involved in resource extraction, mining/oil. Their jobs are location dependent too. They also need services.
I type this while at work (military) with two doors open to outside. There is a pleasant breeze passing through the office. This weather holds for more than half the year. But if one more person moves here, driving up my rent again, I'll start running the AC just to speed up climate change.
Similarly, the personal automobile made urban sprawl possible. But is sprawl and ensuing car-dependency a good thing all things considered? Many would say no.
I wouldn't pull too hard on that thread here, though.
(I'm posting from Houston.)
Second: isn't the shift you describe also a significant contributor to sprawl, which also increases energy waste?
>Second, air-conditioners use so-called “F gases” (such as hydrofluorocarbons, or HFCs) as refrigerants. When—as is common—the machines leak in use or on disposal, these gases escape, doing vast damage. HFCs trap between 1,000 and 9,000 times as much heat as the same amount of CO2, meaning they are much more potent causes of global warming. On this basis, Paul Hawken of Project Drawdown, a think-tank, calculates that improving air-conditioners could do more than anything else to reduce greenhouse gases.
A while ago (back when Google worked) I stumbled upon a refrigerant hacking page that detailed DIY retrofitting of refrigeration equipment to use propane as the refrigerant instead. Obviously the flammability is a problem, but as standard refrigerants seem to be pressing towards the flammable-with-harmful-combustion-products direction, I wonder why the industry isn't reconsidering. It seems nicer to have a plain fireball rather than one which creates hydrofluoric acid.
https://www.epa.gov/snap/substitutes-residential-and-light-c...
I believe that products using these low-GWP, zero-ODP refrigerants are marketed using the term "Greenfreeze."
https://cleantechnica.com/2008/09/29/first-greenfreeze-clima...
Considering that your average refrigerator contains a quite modest amount of refrigerant, compared to all the other flammable stuff in your average apartment, it's not really any significant fire risk.
Thanks for links!
For some depressing reading, see https://theintercept.com/2018/08/25/chemours-epa-coolant-ref...
Well, it's both.
There is great potential in so-called "natural refrigerants", primarily CO2, ammonia, propane, butane. They can be ~as efficient as the various F gases, without leaving nasty chemicals in the environment, and have pretty low GWP's (CO2 equivalent).
I have visited both Texas and HK at peak heat as a tourist - I'm from the UK. Yes it does get a bit warm in both Dallas and say Kowloon but you learn to adjust. You slow down and bimble. You notice shade and instinctively go through it. You keep yourself hydrated and lots of other tiny strategies. This is how people have done it for centuries. I did live in the Middle East for a few years, so that gave me a few pointers.
A/C is nice but not necessary (for a real value of necessary)
It's not a stigma, but a reality. Humans survive in a certain temperature range. On large parts of the earth for large parts of the year, the outside temperature is below the safe range. On only a few small parts of the earth - often where there are no other resources - is the temperature above the safe range. Humanity survived 200,000 years without A/C; I'm guessing heat was a necessity pretty early on, at least to inhabit most of the planet.
And anyway the question is irrelevant. We need to reduce energy consumption; is this some sort of competition between the heating and a/c industries?
My problem with AC is how ubiguitous it is, and how people use it without thought of the environmental cost. It's ridiculous in many cases: people who sleep with their windows open and AC on (this exists), AC bus travel, where one needs a jacket, jeans and warm socks as the bus will be cold after a few hours. Air conditioning shows how far some people have become distanced from nature, and the environment in which they live. People who live in warm climates should expect to feel warm, maybe (at times) uncomfortably so. But good building design, suitable clothing, an open window, and a fan when temperatures get unbearable can go a long way. In the summer, I sleep (comfortably) with a window open, listing to the sound of my neighbours' AC units kicking in. It's depressing.
That's not to say that AC doesn't have valid uses, but that in many cases a more balanced, environmentally-friendly approach can be taken.
The idea is so that the AC would leak out the doors and entice people to want to walk into the store. But that means that all the AC is wasted.
This kind of irresponsible use of AC is everywhere in hot climates in large shoppping streets, pretty much everywhere - North America, Asia (in asia it's insane how much AC is wasted), and I don't see it as much in Europe but probably some stores do it.
That's just a waste and is really sad.
Would you rather they buy Facebook ads and use hydroelectric (assuming ad server's power source)?
Air conditioning has enabled large amounts of people to move from cold climates to warm climates (places like Dallas and Hong Kong basically wouldn't exist like they do without it). And there is a lot more energy spent heating in the north than there is cooling in the south. So on average, I would assume there is a net benefit if you consider the tradeoffs.
I think there is a stigma people have that heating is essential for life, but A/C is optional. But we should really compare them against each other.