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November 29[edit]

Avaaz[edit]

Hello, this is quite important, I just learned that the Avaaz.org site, to which I am subscribed, has been qualified as a cult by the website here http://sab1703.canalblog.com/archives/2013/02/01/27540362.html . I don't know what to think, please? 2A01:CB0C:38C:9F00:6871:1F84:B039:D668 (talk) 09:59, 29 November 2022 (UTC)[reply]

And do you have reason for trusting sab1703? I have no idea whether or not they're trustworthy - I've never heard of them before - but from the little i can find about them (nothing independent) they look like an anti-vax conspiracy theory outfit. ColinFine (talk) 11:38, 29 November 2022 (UTC)[reply]

I see Avaaz described on that blog as a hoax or scam, not as a cult. The blog post does insinuate – without a shred of evidence – that Avaaz may be part of the Church of Scientology, which is sometimes characterized as a cult (or a criminal organization). The description by The Guardian, quoted in our article on Avaaz, offers a more appropriate qualification. --Lambiam 12:53, 29 November 2022 (UTC)[reply]

Steamy storm drains[edit]

Hello! Often in the winter where I live, in the mornings when it's cold, I will see what appears to be steam coming out of the storm drains. I don't actually know if it's steam since it's always when I'm driving. But I'm curious, is there a reason I see this in the mornings? The water that goes into the storm drains normally is most likely not warm enough to produce steam. ― Blaze Wolf^Talk_{Blaze Wolf#6545} 14:53, 29 November 2022 (UTC)[reply]

I don't know the exact design of storm drains in your area, but I assume they are moist on the inside and warmer than the outside air on winter mornings. So there can be moist, warm air coming out of them. This warm, moist, almost saturated air mixes with colder, dryer, but still almost saturated air, producing a mixture of medium temperature and medium humidity. The saturation vapour pressure of water depends non-linearly on temperature, so this mixture may be over saturation, leading to condensation. It's the same reason why you may get mist on winter days forming over open water. So the stuff coming out of the storm drains is best called mist. PiusImpavidus (talk) 16:23, 29 November 2022 (UTC)[reply]

Ah interesting. Also when you say "I don't know the exact design of storm drains in your area" are you referring to the stuff that's visible on the surface on the side of roads or the stuff below the actual grate cover (or just a sort of hole in the curb)? ― Blaze Wolf^Talk_{Blaze Wolf#6545} 16:29, 29 November 2022 (UTC)[reply]

I assume a storm drain is a conduit to carry away rainwater from the streets and/or buildings, separate from the sewers for waste water, and probably covered. The relevant bit here is that there are some openings to the outside air and that the inside can remain significantly warmer than the outside air on winter mornings. PiusImpavidus (talk) 21:05, 29 November 2022 (UTC)[reply]

Is that not what a storm drain is? Or is it called something else where you are from? Ah alright that makes sense. I was wondering if it was something the city did to prevent the pipes or whatever from freezing when it gets too cold, but clearly I'm wrong. ― Blaze Wolf^Talk_{Blaze Wolf#6545} 21:07, 29 November 2022 (UTC)[reply]

In my country, people normally speak Dutch, so we have a different word. Maybe we also have a different style of drains. PiusImpavidus (talk) 10:26, 30 November 2022 (UTC)[reply]

Some cities (famously New York) have public steam systems (often called district heating). See New York City steam system. This steam can leak out of the system, and may be what you are seeing. --Jayron 32 19:03, 29 November 2022 (UTC)[reply]

Steam heating systems, nice. Although providing the heat at a somewhat lower temperature might be more efficient. A district heating system leaking heat into the storm drains may work to. PiusImpavidus (talk) 21:05, 29 November 2022 (UTC)[reply]

Steam is likely to transmit heat energy better than liquid water because of the heat of vaporization. Of course, using hot liquid water instead of steam might improve efficiencies in other aspects of the system; I can't say. --174.89.144.126 (talk) 08:06, 30 November 2022 (UTC)[reply]

I used to work at a large oil refinery (currently the biggest in the UK, according to a recent news story). Such refineries produce as byproduct plentiful quantities of mixed inflammable gases, called "refinery gas", which couldn't be economically separated and sold as product, so instead it was burned to create energy – in the form of heat – for use in all sorts of processes on site. How to supply it? It was used to create steam, which was distributed by an aboveground/overhead network of (very) large insulated pipes. If using hot water had been overall more efficient, I imagine that would have been done instead.

In the right weather conditions, minor leaks from this pipework used to shroud half the site in mysterious wreathing vapours – it was great fun taking busloads of schoolkids and other visitors on conducted tours around the site, and not explaining what (and how harmless) these were until halfway through. {The poster formerly known as 87.81.230.195} 176.249.29.80 (talk) 09:33, 30 November 2022 (UTC)[reply]

Steam can provide a lot of heat at a fixed temperature of 100°C (assuming atmospheric pressure), but for most domestic (not industrial) applications, that's ridiculously hot. When providing the heat at a lower temperature, the heater can be more efficient and more sources of waste heat can be utilised. Modern systems tend to run at lower temperatures, although sometimes it's a political decision. I remember a few years ago, there was a project to pump waste heat from the Europoort industrial/port area near Rotterdam to the greenhouses in the adjacent Westland. It was decided to make the system run on water of (I think) about 60°C. The electric power company owning a coal-fired power station in the area had suggested to run the system at no more than about 40°C, which would still have been hot enough to heat the greenhouses to around 20°C and would have allowed the power station to provide a lot of waste heat (up to a gigawatt), saving on natural gas heating in the greenhouses. It looks like that decision was taken so that (a) the greenhouse owners could claim they weren't coal powered and (b) the power company got a less powerful position. PiusImpavidus (talk) 10:26, 30 November 2022 (UTC)[reply]

Steam heat in general was a very common way to provide heat to buildings in the past; generally a boiler was used to make steam, which was sent via pipes to individual radiators in rooms around the building. Central heating#Steam has some information on this as well. Even individual houses had steam heat. My grandmother lived in on the ground floor of a two-apartment home that had a small boiler in the basement, heated by natural gas, there were steam radiators located in all of the rooms of the house. What makes district steam heating systems different is that the steam is not provided at the building-level with individual boilers, it is generated at an off-site steam plant and sent via pipes to customers to use for heating. Steam itself is a formerly very common way to heat homes. Modern heating systems tend to be forced air heating systems; these are likely safer, however they require electricity to run fans that force hot air throughout the house. Steam heating systems don't require electricity, they are passive heating systems that work perfectly well even in un-electrified homes; which is why you tend to find it in older buildings. --Jayron 32 13:03, 30 November 2022 (UTC)[reply]

Europe tends to use hot water, not forced air, but these systems too are shifting away from small radiators to floor heating, which allows less hot water to be used, leading to better efficiency. This is really getting off-topic. PiusImpavidus (talk) 21:03, 30 November 2022 (UTC)[reply]

Getting even further off topic... It isn't only for heat. In Hawaii, they are experimenting with forcing cold water through buildings to cool them down. Running the pipes deep into the ocean cools the water down before pumping back up and through the buildings. 97.82.165.112 (talk) 10:56, 2 December 2022 (UTC)[reply]

Just to note that the earlier mentioned District heating but also District cooling cover such systems. The earlier article also has some limited coverage of steam vs water. Deep water source cooling also has general coverage of the system suggested in Hawaii although Sea water air conditioning suggests at least one such system in Honolulu is dead. While the articles are far from perfect, they, especially the heating one, do cover a variety of things including systems like Cold district heating which provides water at a fairly low temperature and then uses heat pumps inside individual buildings to raise or in some lower the temperature; or the lack of proper individual controls in such systems on the former Soviet block requiring people to open windows if it gets too hot. Nil Einne (talk) 14:50, 4 December 2022 (UTC)[reply]