Je gaat naar bed, draait de thermostaat terug naar 15 graden en hebt het idee dat je goed bezig bent. Met een cv-ketel en gewone radiatoren klopt dat ook. Heb je vloerverwarming of een warmtepomp, dan werkt dezelfde gewoonte juist tegen je.

Het bekende advies: 15 graden en €60 per jaar

Het standaardadvies komt van Milieu Centraal. Zet je de thermostaat 's nachts op 15 graden, dan scheelt dat volgens de voorlichtingsorganisatie gemiddeld 4 procent op je gasverbruik, als je de verwarming 's nachts nog niet laag zette. Dat is jaarlijks gemiddeld €60, gerekend met een gasprijs van €1,37 per kuub.

De tip werkt het best als je de thermostaat al een uur voor het slapengaan terugzet: het blijft dan nog een tijd warm in huis. Ook als er overdag niemand thuis is, kan de thermostaat op 15 graden. Doe je dat vier dagen per week, dan bespaar je volgens Milieu Centraal jaarlijks zo'n €120.

Maar onder dat advies staat bij Milieu Centraal een belangrijke kanttekening. Heb je vloerverwarming en/of een volledig elektrische warmtepomp, zet de thermostaat dan op 17 of 18 graden, anders duurt het opwarmen te lang.

Het advies van 15 graden is geschreven voor een cv-ketel met radiatoren. Voor andere systemen geldt een andere nachtstand.

Waarom vloerverwarming geen diepe nachtstand verdraagt

Het verschil zit in de watertemperatuur. In vloerverwarming is het water veel lager van temperatuur dan in gewone radiatoren, en ook een warmtepomp werkt met lagere temperaturen, legt Milieu Centraal uit. Dat bespaart energie, maar het betekent ook dat het langer duurt voordat je woonkamer weer warm is.

Daar komt bij dat het rendement van een cv-ketel of warmtepomp minder goed is als het huis in korte tijd flink moet opwarmen. Volgens Vattenfall, dat zich ook op Milieu Centraal baseert, gaat de verwarming met vloerverwarming of lagetemperatuurverwarming 's nachts maximaal 2 graden omlaag. De energieleverancier schrijft er nadrukkelijk bij: zeker geen 5 graden.

Bij een warmtepomp koop je de besparing 's ochtends duurder terug

Bij een warmtepomp gaat het nog een stap verder. Zet je de thermostaat 's nachts veel lager, dan moet de warmtepomp 's ochtends hard werken. Dat kost volgens Milieu Centraal meer energie dan het huis de hele nacht op temperatuur houden. Een warmtepomp werkt bij een groot temperatuurverschil minder goed en heeft in verhouding meer stroom nodig.

Bij een hybride warmtepomp speelt nog iets mee. Vraag je drie graden binnen een uur, dan haalt de warmtepomp dat niet alleen en springt de cv-ketel bij, schrijft warmtepompmaker Quatt. Bij een volledig elektrisch systeem neemt een elektrisch element dat werk over, en dat heeft een COP van 1. Je krijgt dan dus niet meer warmte uit een kilowattuur stroom dan je erin stopt.

Quatt adviseert daarom 's nachts een graad of twee te zakken in plaats van vier, of de nachtverlaging helemaal over te slaan. Het bedrijf is er stellig over:

Vier graden of meer werkt bij een warmtepomp tegen je.

Ook installateur Nova Clima waarschuwt dat het financieel nadelig kan uitpakken als de cv-ketel het huis 's ochtends weer moet opwarmen in plaats van de warmtepomp. Volgens het bedrijf heeft een drastische nachtverlaging bij een warmtepomp daarom vaak geen zin.

Met een warmtepomp is gelijkmatig doorstoken vaak goedkoper dan afkoelen en weer opwarmen.

De nachtstand per systeem

Voor de hybride warmtepomp geeft Milieu Centraal een advies dat afhangt van je isolatie: 's nachts 1 graad lager als je woning redelijk geïsoleerd is, 2 graden lager bij matige isolatie. Voor een hybride warmtepomp in een matig geïsoleerde hoekwoning noemt de organisatie op die pagina een besparing van €50 per jaar.

• Cv-ketel met gewone radiatoren: 's nachts 15 graden, een uur voor het slapengaan (Milieu Centraal)
• Vloerverwarming: 17 tot 18 graden, of maximaal 2 graden lager dan overdag
• Hybride warmtepomp: 1 graad lager bij redelijke isolatie, 2 graden lager bij matige isolatie
• Volledig elektrische warmtepomp: 17 of 18 graden, het huis hoeft 's nachts nauwelijks af te koelen
• Vloerverwarming met warmtepomp: liefst nauwelijks of geen nachtverlaging (Nova Clima)

Zit je met een gewone cv-ketel, dan valt er buiten de nachtstand meer te halen bij de ketel zelf. Daarover schreven we eerder in Kastje onder je radiator scheelt zelf maar een tientje per jaar, deze ketelinstelling levert veel meer op. Hoe je de warmte goed over alle kamers verdeelt, lees je in Ene kamer warm, andere koud? Deze afstelling kan je tot 15 procent gas besparen.

Wat je nu kunt doen

• Kijk eerst welk systeem je hebt: radiatoren op een cv-ketel, vloerverwarming, hybride of volledig elektrisch.
• Heb je radiatoren en een cv-ketel? Programmeer de nachtstand op 15 graden, een uur voordat je naar bed gaat.
• Heb je een warmtepomp of vloerverwarming? Verlaag 's nachts hooguit 1 à 2 graden.
• Laat de thermostaat 's ochtends geleidelijk oplopen: volgens Quatt redt een warmtepomp het zelf bij ongeveer één graad per anderhalf uur.
• Gebruik een klok- of slimme thermostaat, zodat je de nachtstand niet elke avond zelf hoeft in te stellen.

Bronnen: Milieu Centraal (bespaartips verwarming), Milieu Centraal (slim verwarmen met een warmtepomp), Vattenfall, Quatt, Nova Clima

I’ve been really pleased with how KDO comments are working lately — you folks have been lively, informative, fun, and pushing conversations beyond what I can individually manage. And the vibe of the threads are more closely matching the vibe of the community guidelines. All good! The one-size-fits-all-ness of social media has its advantages, but some are looking for quieter spaces and more orientation around community and shared sensibilities. Through the comments, KDO has been growing into one of those places.

Note: comment threads on the site are free for everyone to read, but in order to participate, you need to be a KDO member. Join us if you fancy a group chat.

In order to give us a few more tools to facilitate conversations, I’ve been working on some new stuff over the past few days and some of it just went live:

• Improved thread design. More compact (not so much indentation) and better on mobile especially. I feel like some of the spacing isn’t quite right yet, but that’s easy to tweak as I see how it works on real threads. I spent a lot of time trying to get the right mix of simplicity and info into the comment design, so I hope it works.
• Images. You can add images/photos to your replies now — just paste or drag them into the comment editor or use the image button in the toolbar. You get two images per comment. From the community guidelines: “Posting images and embeds (video and audio) should safely err on the side of utility. I love Phillip J. Fry waving a wad of cash and saying ‘Shut Up And Take My Money!’ as much as the next person, but we’re not doing reaction GIFs/images/videos here.” Animated gifs will not work.
• Embeds. Pasting a link to a YouTube video, Vimeo video, or SoundCloud audio on its own line will embed the appropriate player right into your comment. You get two embeds per comment.
• Replies. You can reply to individual comments now. Threading is still only 1 level deep (i.e. there are “top” comments and replies indented under those top comments) but each reply now tracks the comment you’re replying to. (This is difficult to explain! But hopefully easy to understand when you’re looking at a comment thread.)
• Better reply tracking in “latest” and “popular” sorts. When comment threads reach a certain number of comments, you’re able to sort them reverse chronologically or by number of faves. Previously, it was difficult to distinguish “top” comments from replies to comments (which often read as incomprehensible outside of their context). Now, each reply shows a) who it’s in reply to, and b) a snippet of the replied-to comment (which you can click to read in the thread). Again, difficult to explain (we’re firmly into “how the sausage is made” territory here…my eyes are glazing over re-reading this…) but easier to use — I hope!
• Mentions. You can mention another member in a comment. Typing “@” and a couple of characters will bring up a list of members who have been recently active on the site — select the one you want and their name will appear in your comment. Their name will have a dotted line under it and hovering over it will bring up their profile bio (if they have one). I hope this will be useful in referencing and connecting replies in threads (e.g. “I love what Franklin G. said in his comment and will be thinking about Maggie W.’s reply as well…”) and also between threads (e.g. “This reminds me of something Darcy Wong wrote last week…”). You can’t see your mentions on your profile page yet, but I will be adding that soon.
• Reposting social media posts. I’ve been able to do this in threads for quite awhile (here’s a recent example) and I just opened it up for everyone else. Post a public Bluesky or Mastodon link as the only thing in the comment box and it will automagically expand to a repost (including up to two images from the post). No idea if anyone else will use this! But it’s there.

Ok, I think that’s it? At least for the public-facing stuff. I’ve also been tweaking the KDO post editor (Movable Type is now completely out of the loop, RIP to a real one) and it’s getting goooood. I’ve been streamlining the posting process, especially for adding images and doing Quick Links, and it’s really a pleasure to create posts now. More to do on this front as well.

Anyway, feel free to try some of the new stuff out in the comments — I’m hoping this will make conversations easier to follow, both for participants and readers. I’ve got some ideas for further improvements, but I wanted to get these out here for now. As always, your comments and suggestions are welcome! And thanks for your membership support — it means I can spend time making improvements like this.

Tags: kottke.org

Herring, flatfish and oysters are increasingly off the dining table, with just five fish species now dominating

In days gone by, the UK’s domestic cooks were an adventurous lot when it came to seafood, prepared to dish up anything from an oyster cocktail to whale meat curry.

But an academic investigation of more than 1,000 fish and shellfish recipes published in a lifestyle magazine over the last century suggests tastes have become much narrower. Ruth Thurstan, from the University of Exeter, studied seafood recipes published in the British version of the magazine Good Housekeeping from 1923 to the present.

Pre-1970s: A diverse mix of species in recipes. No single group ruled but flatfish, herring and oyster were prominent. Recipes emphasised domestic skills, economy and preparing whole fish.

The 1970s shift: A decline in diversity of fish species in recipes, with increased focus on the “big five”.

1980s-present: “Big five” present in the majority of recipes, with a decline of other species – though not all have vanished entirely.

If far right nationalists gain power in four big countries simultaneously, we are in for a dramatic Trumpian tilt

When it comes to Europe’s economy or its peace and security, it is obvious that decision-making has to be done largely at the European level to be meaningful. Yet electoral politics is still conducted mostly at the national level. The silver lining of this mismatch is that from country to country in Europe we have governments with different political priorities and leanings. Unlike in the US, where one presidential election can radically change the entire country’s course, as we have seen so vividly under Donald Trump’s leadership, the same drama has not so far unfolded in Europe. This may be about to change.

Pedro Sánchez rolled the dice in Spain last week, calling a snap election for next month after an unholy alliance of the conservative People’s party (PP), the far-right Vox and Catalan pro-independence party Junts blocked his big housing reform package in parliament. If the socialist prime minister, hailed by progressives globally but demonised by Europe’s right and Trump’s US, loses his election gamble, Spain could fall into the hands of a conservative/far-right coalition, which is currently ahead in the polls.

Nathalie Tocci is a Guardian Europe columnist

At first the idea of mercy was something that helped me through the ordeal. But would real forgiveness be a form of Stockholm syndrome?

I knew Mohamed Tahlil as a gentle pirate who oversaw a team of guards during the first months of my life as a hostage in 2012. I had travelled to Somalia to report on the outbreak of modern piracy off the coast. On the 10th day, along a dusty road near Galkayo, in the centre of the country, I was kidnapped by pirates. For the next two and a half years, I was a hostage.

I spent most of my time on a thin, sweat-soaked foam mattress on the floor of a dusty room. The dim concrete prison houses changed, but the filth and the circumstances didn’t. Sometimes my captors moved me into the Somali savannah – where we camped in the open and slept on the ground – and for a six-month stretch, I was held on a hijacked tuna vessel, where I joined 28 fishers from east Asia who had been captured about three weeks before I was placed on board. (They had captured me on land, but they were a pirate gang, organised to capture ships at sea.) In each location, pirate guards would sit around with AK-47s and listen to the radio, or else chew khat, a narcotic plant.

The ex-soldier has marched 36,000 miles since he left Hull in 1998. He’s crossed the Americas, Asia and Europe, fallen in love, been held at gunpoint and been deported, in between nearly drowning, nearly dying of thirst and nearly being eaten. But that’s just the start of it …

‘It’s a big moment,” says Karl Bushby, who has had plenty of big moments in his life. He is recording himself on his phone for social media. “We’re in Dover, and I’m about to have my first fish and chips and mushy peas in 28 years. Mushy peas, my God, I forgot they even existed!” He points his phone at the plate in front of him. “It better be good.” And he tucks in. “Mmmm. See, this is a big chunk of fish and a decent bit of batter, and that’s something you don’t see in other parts of the world. I mean, come on! That. Is. Fish. And. Chips! You see, Britain is special.”

It has been two days since Bushby swam the Channel to return to England. Tomorrow, he’ll start the walk home to Hull for the first time since he left in 1998. He hopes to get back on 1 November, the same date he set off all those years ago.

Over 10m people have tuned in for episodes of new season of BBC hit as mass TV audiences become increasingly rare

For the celebrities chosen as traitors in the BBC’s juggernaut reality show, the task is simple – kill off fellow contestants without getting caught.

Yet with the new series of Celebrity Traitors once again attracting huge audiences, its UK producers are delighting in one of the show’s more wholesome qualities – its popularity is staving off the death of television’s ability to unite the nation.

Cambridge University study suggests stark gender divide in misdiagnosis, with women also waiting longer for treatment

Women with autoimmune conditions are up to 74% more likely than men to be told their symptoms are psychological or psychosomatic, and face much longer waits for a diagnosis and treatment, a study suggests.

Hundreds of millions of people – about one in 10 globally – are affected by autoimmune conditions, which can cause a range of health issues including fatigue, muscle pain and rashes.

ZyMix platform has contract with Tencent, which US alleges has links to People’s Liberation Army

A new messaging and payment “super app” marketed at British students uses servers owned by a Chinese company that has been put on a US military blacklist for its alleged affiliation to the People’s Liberation Army.

ZyMix, which is being pushed on university campuses as the UK’s first super app designed “for gen Z”, combining chat, payments and community features, has a contract with a German-based subsidiary of Tencent Holdings, a Chinese conglomerate in Shenzhen.

As the Oscar-winning Stasi surveillance film hits the stage, Knightley and co-star Luke Thompson talk about the paranoia at its heart, the cost of theatre tickets nowadays – and their fury at ringtones in the stalls

Unpacking assorted tubs of carrot sticks and salad, Keira Knightley winces apologetically. “I just realised I’ve got very crunchy food,” she says. How apropos that she should consider the impact that her lunch might have on my audio recording when we are here to discuss The Lives of Others, a new play in which the characters are divided between the spies and the spied-upon.

Based on the Oscar-winning 2006 film and set in East Berlin in 1984, the play stars Knightley as Christa-Maria, a theatre actor in a relationship with a director, Georg, played by Luke Thompson. Earwigging on them is Wiesler (Stephen Dillane), the Stasi officer whose principles are gradually challenged and weakened by his round-the-clock exposure to this cultured couple.