10 ms·
> And there is a lot more energy spent heating in the north than there is cooling in the south. Source for this?
by another-cuppa 8y ago
> And there is a lot more energy spent heating in the north than there is cooling in the south.
Source for this?
- 21 8y agoMakes sense, you typically need to raise temperature more in the winter than you need to lower it in the summer. 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.
- pc86 8y agoThis supposition and guessing doesn't really qualify as a source.
- ody4242 8y agoHere is a source for US energy consumption percentages, 1993 vs. 2009: https://www.eia.gov/todayinenergy/detail.php?id=10271 https://www.eia.gov/todayinenergy/detail.php?id=10271
- flattone 8y agoSure ... But I have always found it much less paintful to wear a jacket to stay warm than having only machine solutions for cooling off.
- logfromblammo 8y agoDip shirt in liquid with boiling point lower than water. Re-wet as necessary. 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.
- deleted 8y ago[deleted]
- tudelo 8y agoAre you suggesting that someone should wear a wet shirt so that they can stay warm? Or wear an ice cube to stay cool? I guess I'm missing the joke?
- tgb 8y agoThe intention, I imagine, was that the wet shirt keeps you cool by evaporative cooling.
- logfromblammo 8y agoYes, exactly. 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.
- slrz 8y ago> Dip shirt in liquid with boiling point lower than water. Re-wet as necessary. Can you recommend one suitable for regular use?
- dsr_ 8y agoEthyl alcohol is cheap, highly available; people are already familiar with its particular flammability and toxicity issues and are comfortable handling it.
- frandroid 8y agoTo heat, you just run the electricity through resistance. To cool down, you need to run a compressor, it's pretty energy-intensive. Anyway, each place has a different cold/warmth quota so you can't issue a universal rule.
- danmaz74 8y agoActually, heating with a heat pump is much more efficient than using a resistance.
- Tharkun 8y agoThat's mostly true, but only if the temperature difference isn't too high. During the coldest days of winter -- or when boiling water, I'd imagine -- the COP can be as low as 1, ie the same as resistive heating.
- JaimeThompson 8y agoIn most cases doesn't it take less energy to move head (aircon) and more to generate heat (resistive heating)?
- deleted 8y ago[deleted]
- sp332 8y agoHeating using resistance is inefficient and gets you at most 1 unit of heat energy per unit of electrical energy. Heating and cooling using heat pumps can move more than one unit of heat energy per unit of electrical energy.
- timr 8y agoHeating via electrical resistance is 100% efficient. All energy goes into generating heat. There is no loss. Gas heating is something like 90% efficient now. People, stop. Downvoting doesn't change facts.
- dogma1138 8y agoThis is actually correct, here is a comparison between Miami and Minneapolis. http://iopscience.iop.org/article/10.1088/1748-9326/8/1/014050/pdf http://iopscience.iop.org/article/10.1088/1748-9326/8/1/0140...
- TheBeardKing 8y agoTLDR: Minneapolis uses 3.5x the energy of Miami for climate control.
- jrd79 8y agoBut isn't electricity much more expensive per energy unit than natural gas? I don't have an ax to grind on this, but it seems like comparing apples to oranges if cost is a concern (which it may not be).
- woobar 8y ago"Efficiencies of power plants for the energy used for cooling relative to heating" is included in the number above. The factor is 0.5 for heating.
- jrd79 8y agoI wasn't referring to efficiencies. I was referring to dollars per unit of energy, as paid by the end consumer. That "study" explicitly says it didn't take that into account. Electricity is expensive, as anyone who has ever lived in an apartment with electric radiators knows. Natural gas is cheap. My electric bill exceeds my natural gas bill every month of the year, and I live in Minneapolis with electric AC, a high-efficiency natural-gas-fired furnace and boiler (the latter for in-floor), and a modern well-insulated house. My anecdotal experience led me to question whether that study actually showed what it suggested it did. On careful reading, it turns out I was right. People with an ideological ax to grind are bad at research, and bad at analysis. Data should lead the way.
- 8y ago
- another-cuppa 8y ago> And you need heating non-stop in winter 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.
- codexon 8y agoYou must live in a warm place because if I turn off the heating when it is 0 degree celsius outside, then I wake up in the middle of the night because my face is numb.
- ody4242 8y agoYou should invest in thermal insulation. When I turn off the heating for a weekend, and there is cold outside, the temperature inside only drops ~2-4°C during the whole weekend.
- codexon 8y agoThe house as insulated as it can be without costly work being done on it and trying to plug up every leak. It seems like you either have a small residence or state of the art design to only drop 3-4 degrees after an entire weekend, or that you also live in a warm place.
- lurquer 8y agoAgree. It is odd though that this thread doesn't address clothing. It's fairy straightforward to stay warm in a cold environment using clothing, but impossible to use clothing to stay cooler in a warm environment. People up north, technically, probably use more energy heating than they really need to. (i.e., everyone could wear sweaters and coats inside.) On the other hand, in the south, A/C is absolutely essential to be comfortable.
- crazygringo 8y agoIt's hard to type with gloves on.
- Aramgutang 8y agoClothing isn't the only option to stay cooler in a warm environment. Drinking water is quite effective. Just plain tap water is cool enough, but if you want to drink smaller amounts, there's always chilled water in the fridge or ice in the freezer. 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.
- distances 8y agoYou probably know already, but it's worth mentioning that drinking too much water can be deadly. There have been deaths in water drinking contests too.
- Aramgutang 8y agoYes, the stunt I pulled in college was dangerous, but adding a gallon or even two to a healthy adult's water consumption throughout the course of a day is not. Especially considering the sodium content of modern diets. And those can be supplemented by snacking on crisps, pickles, or salted nuts, if needed. 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.
- AngryData 8y agoBut for heating you don't have to use electricity, you lose less energy burning propane for heat than if you burned propane to make electricity to deliver 100 miles away to turn back into heat. And there is always the option of wood burning which is common in northern areas and also renewable and cheap. Producing heat is 100% or more efficient, producing cold air is far less efficient.
- maxerickson 8y agoEven really nice furnaces lose some energy up the flue, so they are less than 100% efficient. They hit ~95%, which is really good, but it's less than 100%.
- sokoloff 8y agoHeat pumps can exceed 100% efficiency (as measured by heat moved into the building divided by energy input to the heat pump).
- maxerickson 8y agoIf we are being pedantic, they aren't furnaces with flues.
- xutopia 8y agoI live in Montreal and my house is well insulated. Even with a single A/C unit I can keep my house comfortable during a heatwave (one of which we had this summer that was devastating for the province). My summer electricity bill is about 1/4 of what it is in the winter time.
- mixmastamyk 8y agoCooling in the north is not expected to be the same. ;-)
- lostapathy 8y agoA big factor in this is how much it cools off at night. It’s easy to cope with heat and design buildings around cool nights, but when the overnight low is over 90, you need air conditioning.