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This is what I used! At some point I managed to block DHCP lease renewals on my computer, and Internet would always stop working after a given timespan. Took a good while to figure out I caused the problem myself.

and that's how you learn...

Shooting yourself in the foot really helps to built intuition!


It is probably easier these days when you have a phone to fall back on for if you break the internet on your computer.

Playing with your router is still a pain though, especially if you don't have a device with an Ethernet port. You learn all sorts of fun things like "If you change your router's IP address you get logged out of its management at the old IP address" and "Oh, that's what subnet mask means, weird."


> It is probably easier these days when you have a phone to fall back on

Most definitely. The old lessons were hard learned, and they stayed with you. Going through everything, trying all the combinations, and reading obscure materials for any hints.

I don't want to glorify the old hard way of spending perhaps days on problems that ended up being trivial, but it's obviously different now when one can get all the answers and helpful scripts directly from LLMs. Much less is retained.


Sometimes called "high instructional value".

In effect they are, even if not directly. There are requirements to stay aware of your surroundings. If you cause an accident by blocking all sounds, I totally can see insurance companies claiming this is your own responsibility and refusing to cover.

I wonder how heat pumps would work for apartment building central heating systems. The circulated water has to be a lot hotter than heat pumps are capable of, as far as I've understood. Is there already a system that could viably replace gas in the existing building stock?

Another problem is that most people in Berlin/Germany are renting, so the incentives do not align. The building owner doesn't pay for the heating, so they are unlikely to do any investments where the upside is for the tenants only.


Heat pump hot water is very common in Europe. Just as it's possible for the pump to make a box so cold that food stays frozen despite the hot summer's day in Florida, it's also possible to heat up a tank of water this way, it just costs more energy.

Unlike modern natural gas boilers which have only a very small tank of water kept hot and use a fire to make more on demand with only a few seconds of delay (you might not even realise this is happening, but of course it isn't actually instant and so there is a small tank of very hot water) the heat pump will need a large tank because you're going to put about a day's supply of hot water in the tank and gradually, over a whole day, re-heat it as needed.


The problem is the old building stock (say, large apartment buildings from early 1900s) which isn't energy efficient at all, and on cold winter days require very hot water to keep warm. The radiators were designed with assumption that the water can be boiling hot (coal/gas).

It doesn't seem feasible to renovate everything, so I'm wondering what are the practical options. A hybrid system where a gas boiler is kept for the peak demand?


There's no chance at all that you're using boiling hot water (373K) because that stuff is both dangerous and unreasonably expensive to make at volume.

My guess is that what you're thinking of is the water being say 320 to 340K, which is obviously far warmer than you'd heat a home, but isn't boiling water. Heat pumps will be more efficient at lower temperatures, so maybe it's keeping that tank of water at 320K while your gas boiler was 330 or even 340K -- but the gas boiler is more efficient for lower temperatures too, ask any manufacturer or installer, the way to get lower costs is to turn down the local thermostat, it's just that people are used to "instant" heat from a gas boiler and won't tolerate answers like "Run it for a whole day" whereas that is what your heat pump needs.

It is true that because of this "Run it all day" approach an uninsulated home is so expensive to heat that it's impractical, when I grew up there was ice inside my bedroom window when I woke on a winter's morning, it had been under 270K at night, and a gas boiler would heat it in an hour or so -- but that's not because it's literally impossible with heat pumps it's just far too expensive.


No, 47°C to 67°C is way too low. The buildings are not actually circulating boiling water, but not too far either:

> Typically, heating systems in Europe use water flowing through pipes and emitters (radiators) heated to high temperatures (70-90°C). [0]

The radiators are often designed for these temperatures. Supplying with lower heat will not work without replacing the radiators and/or renovating for better energy efficiency.

And heat pumps, AFAIK, can't supply 70-90°C. Thus my original question of what is the current plan to solve this problem.

[0] https://www.ifeu.de/fileadmin/uploads/Publikationen/Energie/...


So, firstly yes, exactly, even in the 19th century they aren't using boiling water, it's just needlessly expensive to make. 90°C seems unnecessarily hot to me (as you can see, by the time I was born it wasn't being used to heat homes) but it isn't boiling.

And yes, some older buildings will need refurbishment, these building often pre-date electric light so that's happened before. The 1970s house example starts with a 70°C flow, but with a combination of insulation and replacing radiators they get to 41°C flow which is a much cheaper 318K in real numbers.

The thing is making 90°C water was expensive and unnecessary even when gas boilers start being commonplace, the manufacturer will tell you that you should turn it down until it's heating the home as slow as you can tolerate. That got more true as the boilers got more efficient, because the efficiency is from recovering more heat energy from burning methane and you do that at lower flow temperatures, the heat pumps are just more of the same. Notice how those diagrams show gradually reducing flow temperatures over the years, in the 1930s recovered heat from an industrial district at 90°C is plausible, but the gas boiler manufacturer fifty years ago will go white when you say you need 90°C -- he's going to suggest 70°C, and his successors will keep bargaining you down because the efficiency numbers are better as flow temperature reduces and while "instant heat" feels good in the moment, the bills for the gas you're burning will not.

We can pump these temperatures but they don't make economic sense. Unlike low outside air temperatures this is just economics. The low outside air temperatures mean you need to defrost the pump, which if it got cold enough might literally become impossible, but if you want to pay far, far more money to heat water to 90°C that would be technically possible, it's just silly, like burning $50 bills to keep warm - use singles they're 50x cheaper.


Yes, the buildings will be renovated in time. For me it seems like a generation-long undertaking, though, and we get back to my original question.

I think we're talking past each other, so let's leave it at this.


> Hollywood made that up to paint a picture of the Russians.

I don't think the true version of the events is necessarily any kinder to Russians than this dramatization.


Alas, Finns are not particularly healthy in the cardiovascular department. I don't believe there are any major benefits.

It's much improved tho. A campaign started years ago to wean the general population off the addiction to dairy products.

Just a clarification as it may not be clear from your message. A Finnish ("dry") sauna always includes throwing water on the stove, which is called "löyly".

People have different preferences for the warmth of the sauna -- as low as 65°C for some elderly folks, all the way up to 120°C for more hardcore people -- but water is always thrown on the stove. You won't get burns, but it can have a real sting. It's enjoyable, but may feel uncomfortable as a new experience.


When a swimhall has two saunas, a "hot" and a "hotter", I'd guess they are at about 70°C and 90°C.

70-90 seems reasonable, 90 is already over my comfort which is around 80, but the post talked about >90 degrees which just seems stupidly hot

I don't know anyone who wants sauna that hot - steam is involved. Numbers over 90 sound like dry heat only. My 0,02€.

There's the diary 1660-1669 of Samuel Pepys, which covers as the Great Plague of London, the Second Anglo-Dutch War and the Great Fire of London.

I'm thinking the same. My total computing purchases in the last 25 years, including desktops, laptops, monitors, phones, and tablets is way under 20k.

I would bet it continues to be more affordable to buy reasonable specs with current consumer hardware, rather than buying a top system once.


I haven't purchased a new computer in, at least, 10 years. I take pride (i.e., I have a sickness) in purchasing used laptops off eBay, beefing them up, and loading Debian on them. My two main computers are a Dell E5440 and a Lenovo ThinkPad T420. I, too, am a software developer, but [apparently] not as much of a rock star software developer at this gentleman. :-D

Delusional. In Europe people want not to just see Ukraine win, but also Russia to lose. It's the leaders that are timid, the people would like to see much wider ranging support for Ukraine.

The Russian energy will not be accepted again in Europe for the foreseeable future, ending the war will not change that.


I don't think lossless gives you anything other than, well, lossless compression. EQ or dynamic range compression don't really have anything to do with it.


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