I'm not depressed in the slightest myself, but I just don't see why we try to keep all people alive, all the time, at all cost. Yes, I'm exaggerating a bit, but at some point life ends, and I'm fine with that.
If I have had a nice length of life (lets say something like 70 years), and am no longer happy, healthy or capable of taking care of myself, don't save me next time I need saving (in order to live longer).
(You may already know this) but at least in the US, it's common for older patients to put a DNR (do not resuscitate) order on their medical file, making it so life saving measures won't be taken near/at end of life.
Most commonly this means that CPR can't be performed.
I feel like the point you’re making has never been less true. Dialog boxes with “not yet” rather that “no” are ever more popular. I don’t think that the modern UX designer has much respect for me or my intentions.
> The far-flung complex of mines, ore-processing mills, feed material plants, gaseous-diffusion plants, production reactors, chemical separation plants, metal fabrication plants, and weapon component and assembly plants was still largely concealed behind the security barriers established by the Atomic Energy Act ...
> Of the 3,700 tons of uranium concentrates (U308) that the Commission received in 1953, only about one-quarter (1,100 tons) came from mines in the United States; the rest was produced in the Belgian Congo (1,600 tons), South Africa (500 tons), Canada (400 tons), and Portugal (100 tons). ...
> As for foreign sources, the leveling off of production from the Shinkolobwe mine in the Belgian Congo would be more than offset by projections of rapidly increasing deliveries later in the decade from the Union of South Africa and Canada. ...
Hewlett was (quoting the author) "the first official historian of the Atomic Energy Commission ... [whose] volumes on AEC history are extremely useful resources."
It's just a parameter to let the Android OS know that it's running in an emulated environment as opposed to running natively on a physical device.
For example, the GPU stack has to be somehow emulated using a custom OpenGL driver (in this case `mesa3d`). There's software emulation (swiftshader) and host GPU mode (GLES).
For performance reasons when using the host GPU, the GLES commands from the guest have to be serialized and sent over a kernel pipe to the QEMU and to the host OS. The commands are deserialized on the host and executed on the physical host GPU through the Shader Translator library (taken from the Google ANGLE project). The Google's QEMU fork (aka Android Emulator) usually loads this library and then takes care of proper rendering, such that users can see the rendering output of the emulated OS properly inside the emulator window on the host machine. You can do the same for the docker, otherwise you'd have to implement some other trick to share the GPU. `virtio-gpu` is a Linux kernel facility that is meant to replace QEMU pipe in the future.
Yeah not reading anywhere in the docs that it works without qemu. Also the need for kennel modules to be available on the host and passed through makes it less portable than most containers.
Those kernel modules (`ashmem` and `hwbinder`) are standard when building the Linux kernel for Android and they are already part of the upstream Linux kernel tree [1][2]. Because this solution uses containers (which share the same kernel with the host OS), these additional modules are needed.
From the ReDroid kernel modules readme:
>Custom Kernel
>If use custom kernel (5.0+), you can enable binderfs and ashmem configs; So the kernel modules in this repo are not needed any more.
I will use OBS for recording tech training sessions. It's a robust app that can be set up for anything I need. I develop open source software in a linux desktop environment, and am thrilled by the capabilities of this program to record my workflow.
I commend the author of this post for creating a simple tool for windows. Anything that helps is capture and share knowledge is a win.
Yes but it's buried down in the `Build` instructions. It should be in the About section: "A simple recording program for Windows with the ability to record screens and audio on your computer." (emphasis mine)
Yikes! win 10 or newer?
Win 10 has screen record, with or without audio, built in.
I'm always looking for quick simple browser based things to suggest to friends, and if there is anything cheaper than corel videostudio (when it's on sale) - for win 8, win 7 - which is my preferred tool for the past so many years.
Don't know why you're being downvoted, I build .NET code in Visual Studio on Windows 10 and execute it on my Raspberry Pi frequently. .NET is certainly not a Windows-only technology.
Addendum: It's part of the XBox game bar. In case you are wondering where your recordings are, press Win+G.
It didn't work for me the first time - I had to open the game bar first. Also, I had to focus a Window. I cannot record the full desktop with this technique, so it's not quite the same as the linked application.
What is the built in utility you're using on Linux for this? AFAIK, you need to download a separate utility for recording screens on Linux, or it comes with your desktop environment.
MacOS does have this ability via QuickTime, but I wish I could find something that records my screen + audio output. There is are some hacky ways to do this on MacOS, but I haven't found anything super reliable yet. Though, I believe this is more or less intentional by Apple.
I checked your link, and even did a "command + f" search. I saw no mentions of the words "audio," "sound," "input", nor "output."
Without some sort of fancy hardware or hacky software, I am not sure if it's possible -- at least not as of 6 or so months ago when I was looking for it.
To test:
Use the link above and try to record the audio of something like a YouTube video while recording the screen playing the video. If you can manage to get this to work, please share your results. I would be so obliged. This is not my goal of the software, but it's a quick test to show you what I am looking for.
KDE seems to have a choice of 3 programs for that on the project, but at least on my Debian they weren't installed by default with the minimum KDE. Maybe they come in the full installation.
I'm not American, and I am genuinely curious, why does the FBI investigate this?
I can imagine the US government wanting an investigation in cases like this, and I can understand Beirut wanting (or maybe just allowing) different countries to investigate, but isn't foreign investigations a job of the CIA (or, at least, not the FBI)?
Also if something fishy was happening to that massive stockpile of explosive material it's something that might wind up interesting the FBI for purely selfish domestic reasons.
I'm not sure if you are being serious or not, but I'm sure the US government is getting useful intelligence out of this as well. The US has an interest in knowing how this happened
The CIA is tasked with intelligence gathering and covert foreign operations.
So there may have well been CIA officers around the FBI mission, they would not have played a public role.
If I understand it correctly, the CIA would offer their assessment of the blast to the United States DNI and President. This report might contain unflattering information, evidence of corruption or recommendations of subjects of new or continued surveillance.
Whereas, the FBI, per their publicly accepted invitation would share a classified report with the Lebanese government as an expected result of their visit.
The FBI report would likely be be more consultative, the mechanism of the explosion. Sort of like a car mechanic explaining why your car is making this squeak sound.
Whereas, the Lebanese government would neither have insight into the amount of CIA resources aimed at Lebanon or this particular event, nor how these intelligence conclusions affect US foreign policy in the Mideast.
While possible, I do not believe this would be very likely.
FBI agents must regularly serve in a domestic capacity. That precludes availability for foreign missions.
A CIA officer contributing intelligence would not be obviously investigating because the things they can learn are not so directly gleaned from visiting the site of the explosion themselves.
An example of a CIA officer gathering intelligence on the explosion might be a business person who happens to have trade regularly passing through the port. Perhaps they employ many Lebanese to assist with this effort, some of whom are unwitting sources of intelligence.
By conducting legitimate business, this ambient familiarity with the port, officials working there, gossip of the locals, would provide one point of insight that contributes to an overall assessment by the CIA.
Information from the FBI report would likely be shared with the CIA via the DNI and / or from a direct classified briefing between the agencies. This would probably offer some information that is not shared with Lebanon.
Presumably, the FBI’s opinion on the matter is valuable enough to Lebanon that they okay’d the investigation. Or perhaps the explosion was so egregious that they knew the US would be crawling all over it so Lebanon might as well let some amount of that happen with cooperation so at least they get some information out of it.
"we have 63 legal attaché offices—commonly known as legats—and more than two dozen smaller sub-offices in key cities around the globe, providing coverage for more than 180 countries, territories, and islands."
> FBI personnel abroad serve under the authority of the Department of State, chief of mission at United States embassies, at the pleasure of ambassadors and host country governments.
These are known agents of the United States.
I had meant “precludes availability for covert foreign missions.”
I am not sure of this, however, to me, it does not stand a reason test to use an FBI agent as a CIA agent when they have entirely separate functions and responsibilities.
> FBI investigators came to Beirut after the blast at Lebanon's request.
> A senior Lebanese official who was aware of the FBI report and its findings said the Lebanese authorities agreed with the Bureau on the quantity that exploded.
FBI has specialists that investigate fertilizer explosions. It's not uncommon for domestic terrorists to use this type of weapon in the US. Oklahoma City being a prime example.
The CIA doesn’t really do these kinds of investigations. To be honest I would’ve expected ATF (they specialize in investigating explosions in the US) to have been the US agency lending technical assistance.
One of the remits of the FBI is to protect the US from terrorist attacks. And as the 1993 World Trade Center bombing and the Oklahoma City bombings were fertilizer-based this likely would have fallen into their purview. The CIA is supposed to be concerned only with intelligence-gathering. The FBI has offices around the world. See:
I am American and this was my first thought when reading the headline. “Why is the FBI involved?” I can understand the CIA, like you said. So weird but a sign of our times.
FBI is just "the police", so it's very normal and happens all the time that police experts from one country are invited to help investigate crime in another country.
When I hear CIA, I think coercion to collect information, most usually information to be used to coerce somebody else. When I hear FBI I think coercion to instigate what will be well-publicized conspiratorial crime. Actual espionage and investigation are decidedly secondary activities.
Is this much worse than downloading some installer and running it? Those can be just as compromised. So can packages in package managers for that matter.
Piping straight to bash can be especially bad if you've cached sudo credentials for the current session - some of these scripts call sudo "inside".
Otoh - the connection is signed (it's https)-unfortunately it's often quite easy to compromise a web site. Obviously, listing gpg signatures on the same page doesn't add much unless it's possible to verify the gpg key some other way.
Ed: another problem is that you really should check exactly what's in you clipboard before pasting to a terminal.
The safety in your steps is reading the script, not in avoiding curl | bash. An installer being signed doesn't guarantee it's not malcious; if someone has overtaken a host and replaced the binaries, they'll just sign them themselves. Unless you're manually inspecting the signature matches your expected source, running a signed binary doesn't save you.
True, it does not. I don't recommend downloading (random) binary installers and running them either.
With eg Linux isos, you typically already trust the signing key for your os updates.
But unless you are vigilant about your ssl root certs, you'll easily allow a lot of malicious and incompetent services to potentially intercept most of your ssl traffic... (due to there being many trusted roots by default).
> if someone has overtaken a host and replaced the binaries
This again depend on who and how the binaries are signed, and how the signatures are trusted. Typical windows (and Mac?) setups will gobble up any signature. But if you do check who signs the binaries - then the signing key will easily be the most secure part of the system - a compromised ftp/web site allow hosting malicious binaries, but typically not grant access to the signing key.
With letsencrypt a hacked web site will typically have access to a valid ssl cert - no need to further compromise mx/mail records or gain access to a business phone number etc.
A ascii-armor signed shell script can be distributed safely via a paste-bin. Unfortunately there's no good automatic/standard way to do so. Or rather no standard tool to prompt to trust the signing key - and then run the script - beyond basic gpg --search-key --key-server.. + gpgv.
Maybe signed git repos would be easiest - but I don't know how easy it is to limit which keys are trusted - if it's possible at all?
The helm project does a little dance to try and verify downloads - but for all the effort it pretty much amounts to trusting the script, not the keys/signatures:
I was hopeful sequoia might help - but apparently its sqv tool is even worse than gpgv - neither can handle an ascii armored public key, and sqv can only handle detached signatures.
> The safety in your steps is reading the script, not in avoiding curl | bash
Well, yes. The safety is in doing something between "acquire potentially malicious payload" and "running payload". I don't see how "safety [is] not in avoiding curl | bash" when, avoiding the direct pipe to bash is exactly what I suggest.
If you look at the url, then curl and pipe that url, you have no idea if bash sees what you just reviewed.
But you have exactly the same problem with downloading a binary, or running pip install. You have no idea what that code does, so curl | bash doesnt hurt any more than any other normal methods of installation.
Do you read the source of every setup.py you run before running pip install? Also, if you are untrusting of the source enough to verify their install script is safe, why would you install their template to run on your machine without verifying all of that too? Finally, 10 line bash script might (as tbis example does) just call out to another curl | bash, or to a pip install/npm install.
> Do you read the source of every setup.py you run before running pip install?
I generally run make, setup.py, cargo build etc in the context of cloning a source repository. I certainly could do a better job of sanity-checking those things, but I do try. And I definitely try to avoid having sudo credentials cached when I do - to foil "sudo cp artifact /usr/sbin" and other awful things people do, because they found it convenient.
> Also, if you are untrusting of the source enough to verify their install script is safe, why would you install their template to run on your machine without verifying all of that too?
I generally trust people more to write "left pad" than install scripts. Many sysadmins are good programmers, few programmers are even remotely decent sysadmins in my experience.
> Finally, 10 line bash script might (as tbis example does) just call out to another curl | bash
In which case one has to chase down the rabbit, or give up.
Sometimes one will discover that the end game was downloading a gpg signed tar archive with the release artifacts - and one can go and do that.
> or to a pip install/npm install.
People do do awful stuff in makefiles and package install scripts, but for vanilla python/Javascript - the lazyness of programmers tend to work to our advantage - there be little extra madness/magic in there.
Sute, running pip install -r requirements.txt can do almost anything - but it's unlikely to run your package manager under sudo and mess up your system packages, or add something questionable to your package sources.
> Is this much worse than downloading some installer and running it?
Yes.
You should inspect what you download.
Also, you should probably use the Python interpreters provided by your Linux distro, that stay in directories you usually can't write to and come in signed packages. On a Mac, the next best thing would be MacPorts.
Nothing here overrides there system wide Python version.
The article specificially goes into why not to do it.
> pyenv allows us to set up any version of Python as a global Python interpreter but we are not going to do that. There can be some scripts or other programs that rely on the default interpreter, so we don’t want to mess that up.
Using the Python interpreters in your system doesn't mean you can't make virtualenvs out of them - it's just that they are precompiled and well supported on your specific OS.
I used custom Python interpreters a lot and it's nice to be able to rely on the system to provide a sensible environment instead of forcing myself to build my own.
That's why the traditional Windows way of downloading a setup.exe and running it with admin privileges is a bit scary for people coming from other platforms. Installing an .msi is less bad, or so we are taught.
I think it'll compile various Pythons on your machine under your user. I'd prefer to install (learned this today) with Homebrew multiple versions (not sure how possible it is) as `brew install python@3.6 python@3.7 python@3.9` (because Big Sur has 3.8 built-in).
In reality, I'm a more traditional Unix person and prefer MacPorts, where you can do `sudo port install python36 python37 python39` in a very BSD way of doing things.
Homebrew has broken my computer one time too many.
The script is served over https, so it's not going to be tanpwred with (unless you have a malicious cert, but at that point you can't trust anyone), and curl | bash isn't any worse than downloading a script and just running it, or running a precompiled binary you don't trust.
pyenv could get taken over and you won't know. It's also possible to detect when someone is piping to bash (on the server) and serve a different payload [0]. You're better off piping curl to a file, reviewing the file and then running it manually.
Yes, there absolutely should be. It would be a massive improvement if that happened.
It requires a few extra steps to be actually secure. You actually need to verify the hash from a trusted source for it to be actually secure. If the delivery has been tampered with, you need to ensure that the delivery of the hash has also not been tampered with. In practice, codesigning is the solution, but certs are expensive, and impractical for a small project.
How about the hash being something that you calculate locally?
1. (local) Download the file from the URL.
2. (local) Review it locally, in a text editor.
3. (local) Get its hash locally, from the file in your file system.
4. (SSH) Feed this hash into the fictional tool above.
5. (SSH) If what curl gets is the same as the file that you've reviewed, it gets piped further into bash, otherwise the execution stops and an error is output.
Of course, that's only applicable to this particular case, where a compromised server could detect that a bash pipe is used and return different file contents. That would only be useful in situations where you want to review it on a local device, such as a desktop and run it on a remote one, such as a server.
Edit: If you want to review it remotely, there's nothing to prevent you from using less or something to view it before manually opening it with Bash. That just requires the discipline to not use one liners that both download and run it, as long as no such tool like the above exisdts.
I cant believe I'm going to suggest a blockchain but I think what you really want is:
- run `cu-sh example.com/questionable.`
- this uses `$editor` to let you review the contents (skippable with a command line flag)
- generate a hash of your local contents
- check said hash against a blockchain to see if everyone else who got it got the same contents as you.
- decide from 1 and 2 above whether you actually want to proceed with the install.
You could replace blockchain with checking if it's signed, and the key matches an owner on keybase/github/some other federated identity provider too.
You often want to do this anyway, because the installer often supports various options and env vars. If you download the file you can read its --help output, and even keep it on hand in case something bad happens, or just for your own records.
It's also possible for you to copy things you can't see from web pages. So the command(s) you end up with may not be what you thought. So there's a trust issue with the site you get instructions from ass well.
If you're afraid the host may be untrusted then you would be wrong to download any of their code at all.
The safety is in reviewing the code there, not in avoiding curl | bash. Running pip install or npm install is just as dangerous.
> They should offer a download with signature validation instead. Signed by Apple, Microsoft, etc if possible.
If the host is compromised, the attacker will just get Microsoft to sign their malware instead; see [0]. If the host is compromised, and you run the code without reviwing it, you're hosed regardless.
I noticed a huge difference in how long my clothing lasts once I switched to hang-drying most things. It's not that huge of a hassle and saves energy and I don't have to buy clothes as often. I started doing a lot more hang drying after I bought a bunch of merino wool base layers I use for skiing (which can't really be machine dried).
If you look near the laundry baskets at any home or department store, you'll find comically large 'lingeree bags'. Turns out running anything with a fine weave through these - satin, rayon, exercise clothing, high TPI pillow cases - not only makes them last longer but also prevents pilling.
Always button and zip your jeans, and if you're not in a hurry, cotton clothing seems to be less worn by friction in the dryer than by the high heat. I run a lot of my cotton knits through twice on permanent press instead of once on cotton. And I don't use dryer sheets. Dryer sheets keep your clothes from getting static cling when you have over-dried them, but over-drying them damages them. The static cling is a symptom that you shouldn't ignore.
What you want to do is pull your clothes out when there is just a hint of moisture in them. The air and the latent heat should be more than enough to suck out that last hint of dampness. And if one towel or pair of pants is still damp, nothing stops you from running them by themselves for a couple minutes while you fold the rest.
I do this for cycling clothing. (Almost all synthetic, some wool, fair amount of spandex-y stuff.)
This stuff lasts forever when washed on cool/warm and then hung.
Friends of mine have complained about one brand or another not lasting very long, but they've been tossing the stuff in the drier.
We're fortunate to have a basement with a nice beam I can place hangers on (for winter drying), or a hanging bar I fitted in the garage (for summer). Lately I've been getting rid of 8-10 year old stuff that I no longer like or no longer fits, and it's sellable, as opposed to just worn out.
(Doesn't sell for much, but folks will happily pay $20 - $30 for special print cycling jerseys that are still in good shape and cost $80-130 new. Way better than tossing them in the trash.)
If hang-drying outside, turn your stuff inside out.
UV from the sun kills bacteria, and you want that on the side near your skin, and as a bonus the inside fades (UV again) but the outside doesn't. I have some t-shirts that are quite faded on the inside but still reasonable on the outside.
I assume you mean 40 C, not 40 F? I started washing everything on cold (my washer actually has a 'Tap Cold' setting - just tap water) and it works just as well. I encourage everyone to just try it once - it won't hurt anything and you can always re-run the load - and you will never go back. Also, you don't have to sort clothes.
I read in some credible, non-technical publication, I think the NYT or WSJ, an interview with a engineer in that field (something like detergents or washing machines) who said that detergents used to need heat to enhance the chemical reaction, but that it's no longer true and cold water works just as well.
EDIT: Does anyone know a good technical, authoritative resource on laundry? Consumer Reports has well-researched info, but not in the depth I'd like.
> When a family member is sick, use hot water mixed with chlorine bleach to reduce bacteria in the bed linens and towels. The same goes for cleaning dirty cloth diapers, or other messes.
But also,
> Heating water accounts for about 90 percent of the energy needed to run a washer
So when different clothes prescribe washing at different temperatures, it's because the ‘activation’ temperature of detergent changes depending on whether you use it with jeans or underwear?
As far as I know the clothes don’t prescribe a temperature to be washed at, but rather a maximum temperature threshold upto which the material can withstand without risking damage to itself.
So a 40°C cloth can be washed at any lower temp but might deform or loose color or even breakdown if washed warmer than that.
Instructions haven't kept up w/ washing machines and detergents.
> "Front-loaders and high-efficiency top-loaders run normal cycles 10 percent cooler than agitator washers, and the 'warm' wash temperature in the U.S. has declined by 15 degrees over the past 15 years," says Tracey Long, communications manager for P&G's fabric care products in North America. “Traditional detergent enzymes can be sluggish in cold water so we worked to create a mix of surfactants and enzymes that deliver cleaning performance in cold water across all product lines," says Long.
> Consumer Reports’ past tests found detergents have gotten much better at putting enzymes to work in removing dirt and stains at lower water temperatures, and are less effective at higher temperatures.
If you want to sanitize anything, just use some bleach. It's harsh on fabric, but so is hot water, and the bleach will do a much better job. (FYI, I don't have any whites at all.)
My understanding that was for the special fabrics and/or the dyes used. For example raw indigo bleeds a whole lot more with higher heat. I know there are some fabrics and blends that are fragile compared to something like a cotton tshirt and recommend colder water.
A tip we rediscovered a few years ago(it's well over a century old) is that adding a bit of borax to the washer not only helps get your laundry cleaner, but it will make all your laundry smell better, too, since borax/boron is an extremely powerful agent for killing bacteria, molds, and fungus. My wife is sold, and almost refuses to do the wash w/o borax anymore!
(This might even help deal with the continually scummy front-loader problem, but I can't speak to that as we prefer our 33-year-old Kenmore top loaders that can still actually be repaired rather than replaced with expensive new Chinese/Korean crap every few years. Mechanical timer controls and durable design and mfg FTW! For what it's worth, our total cost of purchase and repairs over 33 years is maybe $1200.00 for the washer/dryer set.)
Or maybe a broken thermostat heater. Apparently this is a separate component sometimes.
What on earth is thermostat heater, you ask? Surprisingly, many dryers apparently have a simple fixed-temperature thermostat, and in order to make lower settings work, a heating element tricks that thermostat into perceiving a higher temperature.
If that heating element doesn't do its job, then the dryer acts like it's always on the highest setting.
> The thermostat heater is often located within the cycling thermostat. However, it may sometimes be a separate component mounted to the dryer's cycling thermostat. Depending on the dryer's temperature setting, more or less voltage is supplied to this heater. Low settings supply more voltage and create more heat, while medium settings supply slightly less voltage, generating less heat. High heat settings will not energize the thermostat heater at all. In this way the thermostat is tricked into thinking that the dryer is hotter than it actually is, so it opens at a lower drum temperature.
That's not true though. The additional energy to create that heat doesn't have to equal the time saved.
You'll notice this in heat pump dryers. They cannot generate the same amount of heat. They take way longer to dry the clothes. But they're way more energy efficient than other forms of dryers.
Edit: I thought of another example. Heating your home with hot water running through radiators. It's significantly more energy efficient to reduce the temperature of the water. This outweighs the additional time it takes to heat up your home. There are various drawbacks and considerations though, e.g. if the house has terrible insulation (noticeable draft) then it'll not be beneficial. There's various other things that'll significantly reduce energy usage, this while anyone would assume that generating heat is already very efficient.
To some extent drying clothes is generating heat (evaporation heat). If you're clever about it you might be able to avoid heating the (wet) clothes and rest of the contents of the dryer (or the outside!) too much. However evaporating water requires an incredible amount of energy, even if you just boil water away then most of the energy is still spent evaporating the water rather than heating the water, so it's not really too clear-cut that running a dryer hot is massively inefficient.
Edit: Also it's not that using lower-temperature water to convey heat is somehow more efficient, the thing with heat pumps is that they are more efficient at heating things to a lower temperature. If you're burning gas it doesn't really matter either way, you just get the energy out you put in.
> so it's not really too clear-cut that running a dryer hot is massively inefficient.
My heat pump dryer came with an energy estimate for various functions and loads. The various functions which shorten the time, or the functions which increase the heat (often related) are specified to use way more energy. To me, it's pretty clear, plus the manufacturer specifies it.
> Also it's not that using lower-temperature water to convey heat is somehow more efficient. [..] If you're burning gas it doesn't really matter either way, you just get the energy out you put in.
That's what I used to assume as well. It isn't accurate though. If the water that comes back to the heating element is too hot it'll not be as efficient as when the temperate is lower. Similarly, the additional energy that's needed to heat the water to e.g. 75+ degrees Celsius is wasteful. You can save around 30% of the energy by reducing the temperature of the water that's used to heat your home (though might not work due to various considerations). There are loads of other things that are possible which also significantly reduce the energy usage.
Regarding how to save energy when using a boiler there's a huge Dutch topic about it with loads of tips: https://gathering.tweakers.net/forum/list_messages/2027810. I assume similar information can be found in other languages, though heating using gas and water is really popular in NL (more so than any other country I assume).
> energy needed to heat water to 75+℃ is wasteful. You can save around 30% by reducing water temperature to heat your home
That depends. For resistive electric it shouldn't make a difference, pretty much all heat is transported.
For non-condensing gas (or wood etc.), if your heater is going full blast and a lot of the heat goes up your chimney and lowering the temperature makes a smaller, slower flame, that gets absorbed better, I think you could get 10-30% difference. The heating of water itself to 20℃, 75℃ or 110℃ shouldn't make much of difference, as you're not supposed to cool the effluents too much, or you get condensation, acids, rust ... which will likely kill you equipment.
Condensing gas is cool, extracting so much heat, that water condenses, but the gas must be clean enough and the condenser resistant to corrosion. Here, lowering water temperature can safely lower the effluent gas temperature for more heat extraction (even in optimal power range), and condensation of resulting water vapor from burning gas is about 10% extra energy that would otherwise go up the chimney. I'd expect about 15-30% more heat than non-condensing, especially if run on lower temperatures.
Heat pumps are quite efficient at moving heat, where 1W of electricity can move 3W of heat for a 4W heating yield. A steeper gradient means more work, so pumping heat from 20℃ to 75℃, 1W may only move 0.5W of heat for 1.5W yield (numbers not accurate). Lowering the temperature can make a 2x difference, or even more in extreme cases.
I wouldn't be too trusting of the claims of a manufacturer who's main selling point is the savings in energy...
They might still be true though, but if you keep in mind that it takes about 5 times more energy to evaporate water than to heat it to 100C, and that heating water is more difficult than most other substances it is really not clear why using more heat would be (far) less efficient. Sure it would consume heat at a higher rate, but also less long.
I'm not sure if heating with cooler water is more efficient.
Some places you pay for the joules delivered into your home. You have flow meter and temperature meters on he input and the output of the radiators and the price for joule is constant regardless of input and output temperatures.
What saves you money is keeping your interior cooler because heat loss is propotional to the temaperature difference.
Dutch energy companies by law have to advise their customers how to save money. The app I use give exactly this advice (lower the temperature), plus various other advices.
> Some places you pay for the joules delivered into your home
That's something different than what I said, no? I'm talking about when you generate the heat in your home. I'm aware of that solution as well, they're efficient because of volume plus part of the heat (energy required) is waste-heat from some industry.
There's still various ways to save energy despite exactly measuring the temperature out and in. E.g. radiator fans.
I know this all seems entirely illogical. Energy in (or required) should stay the same. Practically though, it's probably energy losses that somehow occur and are avoided.
E.g. for the radiator fans people measured if they save energy. They do, though the cost of buying them might outweigh the savings. DIY is cheap though.
> The additional energy to create that heat doesn't have to equal the time saved.
Right, it doesn't have to, but it's also possible that more heat makes it take proportionally less time (or close enough, with negligible decrease in efficiency).
Obviously, yes, using a heat pump will use less energy than a resistive heating element. But the question is more about how much and how quickly heat is input (regardless of how it was generated) and how that affects drying times.
Yes, but it's not a simple linear use of energy. For example, it might use 10x energy to dry twice as fast. That's a gain if you're in a hurry, but not so much if you're relaxing at home, on a tight budget, and/or have unusually high cost of electricity.
It might, but does it actually? Or does it use 2.05x energy to dry twice as fast, making the energy use difference negligible?
Edit: Consider also that the shorter you run the dryer for, the shorter you are running the (substantial) motor and fan, as well as less time spent heating the shell of the dryer and the air surrounding it.
Depends, for most dryers the temperature is limited because water evaporation is taking all the energy. The motor takes the same energy per time, so twice as fast actually uses less energy. However there is a limit to this, eventually (the end of the cycle) you reach the point where water isn't evaporating fast enough to use up all the input energy and temperatures go up to heating clothing fibers to no useful purpose and this is wasteful.
Also, is the dryer located in a climate-controlled part of your home? If so, the air that it exhausts will be made up in equal volume by outdoor air pulled into your living space. How much extra energy does that make your heater or AC use?
From an industry pdf I stumbled across, it looked like moisture sensing improvements were the best bet to save the most energy. Though, I didn't see anything about comparing heat settings in that doc, which may be telling.
Until near the end of the cycle your dryer is putting all the energy into evaporating water, so the temperature inside the dryer is actually fairly cool. Right at the end things change as the remaining water isn't enough to counteract all the energy being put in and so you heat the clothing to no purpose. So at the end off the cycle you should either shut off with a little moisture in the clothing, or regulate the temperature so that the heat input is balanced by the water evaporation.
Sounds like we need ultrasonic no-heat clothes dryers to be commercialised. The technology is there - just play music to the water molecules, and they dance!
The article compares the energy savings over an already inefficient dryer. The article mentions that an existing dryer takes 50min (average). Such dryers are not what anyone should buy, they waste too much energy. Over time it's cheaper to buy a heat pump dryer. Those easily take 2.5 hours to dry. They're significantly cheaper over an e.g. 5-10 year period than buying a cheaper and way more inefficient dryer.
The links to more detail with:
> The goal of this project is to develop a clothes dryer prototype, using ultrasonic transducers, with an EF above 10 lb/kWh.
But also:
> DOE’s Building Technologies Office is seeking new clothes dryer technologies that can increase the energy factor (EF) from 3.7 to 5.43 lb/kWh
The link in the article and my link shows that the intend is to go way over 10 lb/kWh. The link I found showed it could be around 20 or even 44 lb/kWh (seems to depend on the frequency used). This while being way quicker than anything else, especially heat pump dryers.
Yup, I’ve never once in my life paid any attention to any of this, and I only ruined one sweater once. My wife was not happy, it was a brand new cashmere sweater from some brand name. Still though, if that’s my only screw up and amortized over a lifetime of not caring about this, still positive ROI for me. Twist ending: we saved the severely shrunken fancy sweater and now it fits my kids, so not a total loss.
Well, my approach is to limit my day-to-day clothes buying to just those washable in 40°C and machine dryable. Makes both the shopping and life overall so much easier.
Any women who still have to wear business attire interested in a similar approach should check out MM LaFleur. Well-designed, machine washable staple pieces at a (mostly) reasonable price. IIRC the company was founded by a young French woman who used to work in consulting and knows the pain of constantly needing to dry clean your clothes.
Yes, if you only buy things that you wash in 40 degree water and dry in a machine, you can just wash everything in 40 degree water and throw it in a machine.
My rule of thumb is basically just to exclude from the dryer anything stretchy, slippery, knitted, or lacy. With that stuff hung to dry, what’s left is all the plain cotton shirts and jeans that can take whatever you throw at them.
If you have dryer it nearly strilizes everything you just washed with hot air.
I'm washing t-shirts in 40 deg and drying them in my washing machine with built-in dryer.
They come out a bit damp to avoid creasing too much. I never had them smell even though I was just unloading dryer into a huge pile of damp clothes and leaving them like that for a day or two to dry out completely. I even forgot to take them out of the washing mashine and found out few days later. They were still damp but didn't smell. I washed and dried them again though to be on the safe side.
Most washers (especially top loading) in Japan don't support warming water so people wash with cold water, use hot bath water, or hopefully the house has hot water faucet for washer.
I've bought an expensive front loading washer-dryer with water heater (upto 60C) and heat pump dryer recently. Now I always wash with at least 15C water, even 15C, it's significant difference in cold winter situation.
It doesn't sterilize, but it does bind to viruses and bacteria so they can be washed away. It's the reason why you don't need antibacterial hand soap: you don't need to kill, washing off is enough.
If I have had a nice length of life (lets say something like 70 years), and am no longer happy, healthy or capable of taking care of myself, don't save me next time I need saving (in order to live longer).