Wikipedia:Reference desk/Archives/Science/2024 March 20

= March 20 =

Removing air from water to reduce your water bill
There are a number of companies out there that purport to be able to reduce your water bill by reducing the volume of air in the pipe ahead of the meter so that you "just pay for water". (Example site). Leaving aside any issues with the water company, does the science of these things make sense? Matt Deres (talk) 19:32, 20 March 2024 (UTC)


 * The example site you provided is based on little more than advertising hyperbole! I have read it in its entirety and I saw nothing that made technical sense. The great majority of water systems connected to a water distribution network don’t contain air (unless the advertisement is referring to air dissolved in the water.)
 * If this hardware actually achieves something worthwhile this advertisement fails to disclose what it is or how it works. Dolphin ( t ) 21:11, 20 March 2024 (UTC)
 * In my area of the UK, meters are installed under the tarmac of the public pavement (sidewalk) outside the residence, accessed by a very small hatch (they are read remotely), so to treat the water before it reached a meter would likely require excavating the pavement – not a practical or legal proposition – and installing the device (whatever it is) on the water company's pipework, which would likely also be illegal. Moreover, even if it worked, it would likely be a violation of the water company's contractual terms. {The poster formerly known as 87.81.230.195} 51.241.39.117 (talk) 06:39, 21 March 2024 (UTC)
 * What a wonderful advice: "trusting advice about Smart Valves from anyone other than experts like us is ill-advised." Experts "like us" can easily be recognized, because they wouldn't recommend any other valves. So where the ad admonishes, "Don't fall victim to outdated first-generation valves", I fully agree. I'd even go further and say, "Don't fall victim to any valves, whether first, second or third generation." --Lambiam 10:00, 21 March 2024 (UTC)
 * Water metering addresses the issue of air in the water, giving a reference to regulations, but the cite is to an 'International Recommendation' rather than any national law. -- Verbarson talkedits 12:23, 21 March 2024 (UTC)
 * ...and the recommendation specifically refers to 'liquids other than water'. -- Verbarson talkedits 12:27, 21 March 2024 (UTC)
 * Faucets are equipped with aerators specifically to introduce air into the water at the point of use, reducing water use through more effective wetting in the dispersed water, and reducing splashing. Maybe these marketers are trying to make people think that it happens in the supply lines and they're getting cheated?  Acroterion   (talk)   12:33, 21 March 2024 (UTC)
 * It all sounds like a scam. And doesn't dissolved air in the water improve the taste? Otherwise you'd be drinking distilled water, which is pretty bland. ←Baseball Bugs What's up, Doc? carrots→ 16:37, 21 March 2024 (UTC)
 * That would be minerals, at least up to a point. Air, unless it's carbonation, doesn't affect taste significantly.  Acroterion   (talk)   02:56, 22 March 2024 (UTC)


 * Our colleagues over at WikiHow (and many plumbing sites) have addressed this - "Water occasionally comes out of the tap with a cloudy or milky appearance. In most cases, cloudy water is caused by air bubbles in the water, and these will dissipate on their own if you let the water sit for a few minutes." HiLo48 (talk) 03:55, 22 March 2024 (UTC)

Here's another site offering the same kind of thing:, but searching for water valves that remove air to reduce water bills will give you no end of similar items. This one at least has a demonstration video of how it's supposed to work. Many, like the Watergater, tout that they are 'certified' and/or 'approved' which always strike me as weasel-words in this kind of context. Like, they were maybe approved in the sense that they wouldn't explode or poison the water or something, but meanwhile implying that an impartial researcher has confirmed their claims. But just because it sounds fishy doesn't mean that it is, so I guess my questions are: 1) does municipal water typically have significant air in it? 2) does that air actually impact the reading of a standard water meter and 3) is there any chance this doohickey could affect that in a meaningful way? Matt Deres (talk) 14:05, 22 March 2024 (UTC)
 * Regarding (1), the charts here indicate that at normal temperatures (40-80 F) and typical municipal water pressures (60 psi), the ratio of the volume of air to the volume of water is roughly 8% to 13%. This is more than I would have guessed. Whether a valve can change that in any significant way, without changing the pressure, seems doubtful to me but I don't know for sure. CodeTalker (talk) 02:58, 23 March 2024 (UTC)
 * There is a difference between an air and water mixture, and water containing dissolved air (properly, dissolved nitrogen and oxygen, being the significant components of air). To my understanding, dissolving gases in water does not greatly increase its volume (if at all), so it's important to be sure what is being measured: this reference discusses air dissolved in water. {The poster formerly known as 87.81.230.195} 51.241.39.117 (talk) 09:26, 23 March 2024 (UTC)