Wikipedia:Reference desk/Archives/Science/2022 November 14

= November 14 =

How to use natural gas on appliances designed only with propane burners ?
Hello, given identical pipes, and given in Europe Propane is distributed at 34millibars and 20millibars for main gas. Using the Wobbe index, how much natural gas should be compressed in order to reach the level of propane at standard pressure ? 2A01:E0A:401:A7C0:DD84:4D2F:2DD3:58D4 (talk) 00:05, 14 November 2022 (UTC)
 * You should consult an expert to see if it's possible, and to hedge your bets you should get some life insurance for yourself. ←Baseball Bugs What's up, Doc? carrots→ 02:34, 14 November 2022 (UTC)
 * This is for requesting a new device from a professional which will pass certification. Not crafting something myself.
 * But as this is outside the country, I need to give the relevant specs. 2A01:E0A:401:A7C0:DD84:4D2F:2DD3:58D4 (talk) 11:38, 14 November 2022 (UTC)


 * The composition of natural gas differs depending on the source and how it has been processed. The caloric value of Swedish natural gas is substantially higher than that of natural gas from the Netherlands. Compression may not be a good idea: a huge compression is required, resulting in a pressure for which the existing pipes are not graded, domestic appliances are designed for a standard overpressure, and if the gas delivery service uses pressure regulators at the service entrances (see ), the effect of compression will be undone anyway. --Lambiam 07:04, 14 November 2022 (UTC)
 * The underlying issue is portable natural gas stove for cooking (The kitchen can’t be modified) with multiple gas burners as well as forced‑air gas heaters seems to only exists for propane. Propane with bottles is sold 40% higher than main gas in France.
 * Otherwise, the aim in terms of standard is using G20 to G31. The Netherlands in reality use ʟᴘɢ as main gas if I understand correctly. 2A01:E0A:401:A7C0:DD84:4D2F:2DD3:58D4 (talk) 11:36, 14 November 2022 (UTC)
 * Actually, the Netherlands use methane, but impure, as it contains about 14% nitrogen by volume. It comes out of the Groningen gas field that way. That's a single gas field, big enough to provide practically all domestic gas in the Netherlands throughout the natural gas age (1963–2023), so it's of very uniform quality. Making burners optimised for this impure gas was much simpler than removing the nitrogen. I assume the Swedish gas has less nitrogen and maybe more ethane and propane.
 * BTW, more or less portable natural gas stoves with 3–4 burners have been around, but I haven't seen one since the end of last century. And you'd need one optimised for the gas coming out of your pipes. PiusImpavidus (talk) 17:13, 14 November 2022 (UTC)
 * As you know natural gas in France mostly come from ʟɴɢ from Algeria before the Russian war… The Shift to ʟɴɢ from the United States for replacing Russian gas didn’t require changing equipment, hence the reason I assumed G20 was equal. Or maybe the Netherlands don’t conform to G20… 2A01:E0A:401:A7C0:4914:DFDB:AF86:8F9D (talk) 22:29, 14 November 2022 (UTC)
 * Dutch natural gas is delivered at G25. Delivery is slated to terminate in 2030. --Lambiam 08:26, 15 November 2022 (UTC)
 * On my side, there are plans to mostly shut down the central heating of the building I’m living instead of investing in more efficient way of heating. Electricity per apartment is caped at 12Kw while it takes 15Kw to 20Kw per home to heat those apartments without any isolation. So this requires forced‑air gas heaters at least for some years, but all of those I found are working only with ʟᴘɢ or Propane : a converter is needed and some companies agrees to build 1 : but I need to give the design details. Since paying a subscription to natural gas is required, I’m planning to switch to gas stoves for cooking. 2A01:E0A:401:A7C0:FD73:3340:23D9:8642 (talk) 02:28, 16 November 2022 (UTC)
 * You need to find out the specs of the natural gas that is delivered to the building. What are its pressure and caloric value? --Lambiam 04:17, 18 November 2022 (UTC)
 * As I said initially, all fall under the G20 standard which is at 20milliBar sourced from different and varying ʟɴɢ country. A converter is mainly a compressor. So it need to deliver a specific equivalent pressure. 2A01:E0A:401:A7C0:8474:A152:73C7:23E (talk) 14:47, 20 November 2022 (UTC)

How many combinations in garage door remote and TV remote controls?
I heard for garage door remote controls the number is in the order of a 4-digit number? What about for TV remote controls? Do they have an overlap spectrum, so a TV remote can work on someone else's garage door? And vice versa. And I'd make this discussion International. 67.165.185.178 (talk) 06:24, 14 November 2022 (UTC).
 * There will be 10000 combinations of 4 digits 0-9. TV remotes usually uses near infrared, whereas a garage door remote will be a HF, VHF or UHF radio transmission. So the answer to your last question will be "no". Graeme Bartlett (talk) 06:53, 14 November 2022 (UTC)
 * If you point the easiest to skywave frequency of garage opener at the right vector at the right time could a properly positioned friend hear it by skywave? Sagittarian Milky Way (talk) 19:25, 14 November 2022 (UTC)
 * They will only transmit at milliwatts of power and so be difficult to receive a long way off. So they would only work with a range of a few dozen meters. Also only those remotes that transmit around 28 MHz would reflect signals off the ionosphere at certain times of solar maximum. And for these frequencies the wavelength is much larger than the size of the remote, so there is no concentration of power in a beam. So "pointing" won't achieve anything. If your friend has a large Yagi or phased-array antenna they could be a few times further away and still receive a recognisable signal. Your friend will have a noise floor of cosmic noise and noise temperature (antenna) which will limit their ability, even with expensive equipment. And perhaps there will be interference, because there are other users of the radio channel. Graeme Bartlett (talk) 22:08, 14 November 2022 (UTC)


 * So garage remote controls use a 4-digit code? I'm guessing a TV remote control is less? 67.165.185.178 (talk) 02:52, 15 November 2022 (UTC).
 * TV remote controls do not transmit a series of decimal digits. There are various types and different communication protocols. The most common is multi-channel transfer, which can be seen as bit patterns transmitted in parallel, encoded as an FM signal. The RC-5 protocol has a width of 14 bits, but encodes for only 128 possible commands per transmitted pattern. --Lambiam 08:13, 15 November 2022 (UTC)
 * So at 128 commands, channel up from 1 remote control can be channel down in another? Or, power-on in 1 remote can be channel-up in another TV? 67.165.185.178 (talk) 11:10, 15 November 2022 (UTC).
 * That depends on 1) whether the two remotes operate on the same frequency bandwidth 2) whether the two remotes are operating the same protocols 3) how the remotes and TV translate the specific commands. Too many variables to say.  I mean, anything is possible.  In general though, as a consumer, you're going to want to use the remote that came with your TV; OR you're going to want to use a programmable universal remote control that can be programmed to behave like the remote that came with your TV.  -- Jayron 32 12:56, 15 November 2022 (UTC)
 * So Jayron/Lambiam and whoever, has TV remote controls changed (the protocols, frequency bandwidth, and translation) changed when we upgraded from regular TVs to flat-screen TVs? 67.165.185.178 (talk) 00:06, 16 November 2022 (UTC).
 * Maybe? There are too many variables to count in terms of how different manufacturers might do things.  Maybe some modern flat screen TVs use the same protocols as older CRT TVs.  Maybe some have novel ways of doing their remote controls.  It's way too variable to make any blanket statements. — Preceding unsigned comment added by Jayron32 (talk • contribs) 13:19, 16 November 2022 (UTC)

Okay, I looked at the Wikipedia articles for both garage remote control and TV remote control. For garage remote control, had multiple phases. 1st phase = remote control could work on your neighbors garage. Then 2nd phase, it had a 2^8 to 2^12 possible combinations, (maxing at 4,096). But it was still possible to save/record the wave, or try every possible combination. Then 3rd phase, had some 3 billion combos... However, article doesn't say from what years to what years the phases were but I am wondering for TV remote. Then, for TV remote controls, doesn't say about working for other people's TVs but that likely wasn't an issue. But here's a question. Why did when the 1st remote and garage control was invented, why was garage decided to be radio wave and TV decided to be IR wave? And not vice versa? 67.165.185.178 (talk) 23:58, 16 November 2022 (UTC).
 * For a historical perspective, I wrote the article about the Zenith Radio Nurse, the first electronic baby monitor introduced in 1938. It failed because it interfered with early car radios and early garage door openers. Cullen328 (talk) 00:08, 17 November 2022 (UTC)
 * Garage door openers need a signal that can penetrate garage walls made from brick, wood, fibreboard or tiles, and work from a sensible distance. Infrared does not go through, but radiowaves do go through these insulating materials to some extent. TV remotes are not security coded. and one control can operate similar TVs from the same manufacturer. You would not want your neighbor to be changing the channel on your TV. Infrared works fine for a few meters through air, but not going through walls. It may work through glass though. Graeme Bartlett (talk) 11:06, 18 November 2022 (UTC)
 * Are there any thermal IR to far IR signalers and is common glass opaque enough at their frequencies to block them by a literal greenhouse effect? Sagittarian Milky Way (talk) 14:27, 18 November 2022 (UTC)
 * No far IR or mid-IR, as sensors and generators of these waves cost too much. For thermal IR range, there is a lot of background radiation to interfere also. From the past though there were ultrasonic TV remotes, and also ones connected by a cable to the TV. Graeme Bartlett (talk) 20:03, 18 November 2022 (UTC)
 * Too many light bulbs, candles, heaters etc for it to beep a code and attempt to only respond to that? Sagittarian Milky Way (talk) 00:16, 19 November 2022 (UTC)
 * Yes, "beeping" (or rather flashing) a code is what IR remotes do. An IR remote is basically a flashlight (or "torch" for UK readers) with the ability to blink the light on and off in certain patterns. The protocol I'm most familiar with (NEC) encodes a 32-bit code by flashing the light 32 times: a ZERO bit is encoded as a flash followed by a short pause, and a ONE bit is encoded as a flash followed by a long pause. But if there are bright IR sources in the area, the receiver may not be able to tell whether the remote is on or off, so can't detect the flashes. Imagine someone is sending you a message at night by flashing a weak flashlight at you from across a football field. Now suppose they do the same thing in the daytime. The sunlight overwhelms the flashlight and you may not be able to detect the flashes. CodeTalker (talk) 01:29, 19 November 2022 (UTC)