#luften — Public Fediverse posts

@leyrer

#kippen #lüften

Es fühlt sich allerdings etwas sonderbar an.

Es ist wieder warm; für mich sogar zu warm. Exakter: Es ist schwül und ich könnt‘ durchdrehen. Dazu kommt, daß ich nur Fenster in Richtung SSW habe. Querlüften ist deshalb jedenfalls nicht drin. War mir zumindest bisher nicht wirklich möglich […]

So I am maybe 2 mm away from deciding to drill a hole in the wall and put a temperature sensor into it to get reliable core temps.

The last few days have been brutal with 2 days 36C and then 2 days 40C in a row.

So my apparent walls have heated themselves up to about 28C. It was not possible to cool them overnight because the temps only reached 24C and there was not a lot of wind what lead me to measure my fans how much their cone of air is and what the perfect distance to my windows are.

But this still has no effect because fans where just to bad at creating static pressure.
I then sealed a window completely and made 2 holes for the 2 fans which resulted in great static pressure but obviously not much of transit air.

Tonight it was 17C with good wind so I was able to allocate both fans to the walls… but the thermal mass is just so high that my thermal camera still reads 26C at these wall but my wall sensor reads 24C.

So there are 2 issues.

1. the wall has a very high thermal mass that I can not cool down at night with the current equipment.

2. wall must have a bad internal conductivity

This creates issues in my planing when I have to get up to close the windows.

So there are 4 things I will do.

1. I will build a window sized fan out of PC fans that have great static pressure and are silent.
That way I can set up my blinds and windows in a way that I don’t need to be worried that it will rain into my apartment while at the same time having great airflow.

2. I will drill a hole I my wall (3mm or something) maybe 10cm deep and then I will put a temp sensor there to get the core temps of the wall that is clean on not just a sensor on the wall with a blanket over it.

3. I will put one of the fans statically without moving on a wallpoint and measure how the core temps change and how the surface temps will change.

4. I will measure airspeeds and input and output temps of my apartment to measure the rough thermal mass and thermal lag. (And also I want to know how much heat in watt I can shed with just Lüften)

5. with all this data I will be able to create a good thermal model of my Appartement and that will give me a good idea how I can behave in the days before a heat wave and while it is going.

There is maybe a way to put my diy fan into my home assistant and let the fan only run between 2AM and 6AM when it would be beneficial to Lüften.

And I want a system that tells me „in 7 days we expect a heatwave, you have to begin to cool your apartment tomorrow at night.“ while considering dew points and mold prevention if my apartment could become too cold - although I don’t think this is an issue.

And I will be able to get a estimation how hot the apartment will be while a heatwave is going on and maybe just take vacation or get a hotel with AC or something if it gets too extreme.

Like yah yah I could get myself a monoblock and diy it to a 2 hose system but these things are quite big, expensive and expensive to run while I only need them for 3 days a year like this one. And additionally I think small monoblocks are just too weak to cool a apartment of this size idk I would have to calculate it. In any case I want to prevent getting a AC because of space constraints and energy aspects.

I mean the energy price are going up _a_lot_ if a heat wave is coming in and i totally expect that Germany, if a even more extreme heat wave is rolling it would need to shed private homes because the grid would collapse otherwise.
So a Balkonkraftwerk with batteries would be needed if this should be somewhat usable and financially acceptable. Last Sunday it would have been about 0.9€ per hour of running AC at its peak, while still having to pay for the AC and having the hassle of DIYing and putting it up.

I just hope that I can optimize Lüften in my Appartement to a point where it is just not necessarily anymore to have one, even in a heat wave.

I keep you updated if I have new data or ideas.

#heat #hitze #climatechange #klimawandel #diy #luften #cooling

@masek
macht heute die #Lüften hinweise für #Kiel =))

#Update jetzt ist die letzte Möglichkeit.
Morgen früh wird es nach Modell schon mind 24° sein und viel feuchter...

Heute mal nen andere #Lüften #Service für #Kiel

#Hitzewarnung ; die Modellberechnung ist im Moment bei 38,3°C für Samstag

Das wären 2,5°C über der jemals maximalen Temperatur für Kiel!

Diese Nacht und morgen früh ist die letzte gute Chance zu Lüften.

Denkt an die älteren Menschen in eurer Familie oder Nachbarn, gebt die Info weiter.

Update:

I managed to measure the boundary layer temperature of my heavy load-bearing wall somewhat directly. I basically just used an additional air temp sensor, put it on the wall, and covered it with a blanket, leaving a small hole that was faced away from airstreams to account for moisture.

The data is not yet fully clear but as you can see via the graph, the green air temp stops raising when it approaches the yellow wall temp.

I am somewhat sure now that the temp of this wall is the most significant indicator of room temperature after I closed my windows and rolled down the blinds.

Until around 2:30 AM I pointed both of my fans to the windows, after that I let one of them cycle between the window and the wall.

I am still not sure if the fan pointed to the wall to get rid of the boundary layer is significant or if it would be better to just point the fan to the window.

There is almost no air movement I can measure or perceive at the wall if I point both fans to the window.

I think thermal inertia of the wall is quite impressive! It got blown on the entire night with 2C lower air and only lost temp very slowly.
So it is either very bad at conducting heat or it is a good thermal battery.

After calculating the wall is about 3m³ of concrete which is round about 1.75 kWh/K. Which is lower than expected.

The convection exchange of this wall should be pretty low as it is obviously vertical... after looking into convection vs forced exchange (blowing onto the wall) calculation examples I guess that the temp exchange is about 3 to 5 times as high as with normal unsupported convection.

Thinks I want to test and see if they are relevant:

- Messure different setups and distances from the window to the fans

- Messure outside temps to optimize the "closing window" time. I think this should be the time when outside temps are maybe 0.5C under the wall temp as air kWh/K is super low and will be heated almost immediately to wall temp if closed. So even if indoor temp is cooler then outside temp it does not make sense to close the windows as long as outside temp is lower then wall temp.

- Calculate how long and how often a given location on the wall must be blown upon to hit diminishing returns regarding the removal of the boundary layer to determine if it would be better if one fan just randomly blows at all walls, floor and sealing.

- Set up better temp sensors for measuring wall temps.

- Search for heat bridges

- Blowing air at the upper portion of walls since I expected that the delta is bigger there.

Until now it is quite amazing that I can basically safe each day about 3 to 5 EURO on energy because I do not use a AC... which is also not very practical in my apartment.

There are times when this will not work like Sunday when we will have 25C at night and 40C at day.... but yah it is also questionable if a mobile renter friendly AC can even pull down the room temp at these outside temps especially if it is only a unit with 1 or 3 hoses instead of a split AC unit... which are a lot more expensive like 1k EUR and gigantic space wise... for about 3 days a year I cannot cool with Lüften.

Let's see how I think about this at Sunday :blobcatsweats:

#climatechange #ac #cooling #lüften #heat #extremeheat

24°C drinnen, wären ja aushaltbar. Aber wenn man gleichzeitig die Luftfeuchte nicht runter kriegt und die sich auch nicht rauslüften lässt, wird es halt ätzend.

😓 ☀️ 🌡️

Lüften oder besser Fenster und Türen zulassen? ▶️ https://martinvogel.de/py/hitzeindex.py

#Hitze #Lüften #Feuchtkugeltemperatur #Hitzeindex #Schwüle

Höchste Zeit für den alljährlichen Hinweis auf die Lüftungstipps und den Taupunktrechner:

https://martinvogel.de/blog/index.php?/archives/152-Lueften-bei-grosser-Hitze-ja-oder-nein.html

#Hitze #Lüften #Taupunkt #Python #Schimmel #Luftfeuchtigkeit

Tricks für einen besseren und erholsameren Schlaf bei Hitze

Tropische Nächte, schlechter Schlaf. Was hilft jetzt wirklich? Nackt schlafen? Bettlaken einfrieren? Hier gibts Tricks, die bei Hitze helfen.

https://www.swr3.de/aktuell/service/nackt-schlafen-bei-hitze-tipps-100.html?at_medium=social&at_campaign=%40swr3%40ard.social

#Hitze #Schlafen #Tipps #NacktSchlafen #Luften #Bettdecke

Lüften 2.0...

#Fensterfreitag #photography #architecture #WindowFriday #lüften

#Servicetoot
#Lüften

Heute ist wieder super Zeit den Keller zu lüften.

Heute Mittag sind -4° Grad Taupunkt angesagt.

Also (Keller)Fenster auf und den Wintermief rauslassen.
https://kachelmannwetter.com/de/modellkarten/sui-hd/schleswig-holstein/taupunkt/20260426-1100z.html
#Kiel

The window is tilted...

#Fensterfreitag #photography #architecture #WindowFriday #lüften

Die ersten Frühlingsabende und schon wird wieder alles zu einem #Lagerfeuer, was irgendwie brennbar aussieht.

In der benachbarten EFH-Siedlung wird seit gestern abend nach Sonnenuntergang alles verbrannt, was geht -> #Lüften wird so ab 19 Uhr zum Glückspiel. 🤒

#Luftverschmutzung #Abgase

Should We All Be ‘#HouseBurping’?

The German practice of “#lüften” is gaining traction on social media. It may improve your home #AirQuality.

By Dorie Chevlen, Jan. 29, 2026

Excerpt: "Experts say lüften actually works. The Environmental Protection Agency recommends opening windows to reduce the concentration of volatile organic compounds [#VOCs] in the home, which are released by a vast array of household items, including furniture, mattresses, cosmetics and cleaning products. These compounds can cause adverse reactions like headaches, itchy eyes and breathing problems.

"According to Dr. Parham Azimi, research associate at the Harvard T.H. Chan School of Public Health, there’s also reason to believe airing out a home regularly could help control household #mold. In his research, keeping windows closed correlated with a higher likelihood of mold.

"Dr. Joshua Nosanchuk, a professor and microbiology researcher at Albert Einstein College of Medicine and an infectious disease physician at Montefiore Health System, said that better #ventilation could eliminate many airborne toxins that cause people irritation in the U.S. 'Part of the problem is that we hermetically seal our houses. We don’t want the air conditioning to get out and we don’t want the heat to get it out,' he said. 'No one opens their windows.' "

Learn more:
https://www.nytimes.com/2026/01/29/realestate/what-is-house-burping-luften.html

Archived version:
https://archive.ph/pWByt

#SolarPunkSunday #FreshAir #Nature #VentilateYourHomes #AirExchange

Ganz vergessen,

#Servicetoot #Lüften

Liebe Menschen in #Kiel heute ist es mit -10°C Taupunkt so trocken wie warscheinlich das ganze Jahr nicht mehr.

Heute den Keller zu Lüften hört sich komisch an aber ist heute der perfekte Tag für.

The latest issue of Found History (Briefly Noted) is out! This week's stream:

🏛️ The medieval roots of the university
💰 Billionaires don't really believe in UBI
🔬 The myth of scientific "discovery"
📉 EnshittificationU
🪟 Lüften's OK but A/C isn't?

Read and subscribe at https://open.substack.com/pub/foundhistory/p/briefly-noted-for-january-28-2026?r=5jp13c&utm_campaign=post&utm_medium=web

#highered #AI #UBI #histsci #MedievalHistory #luften

USA entdecken deutsches Kulturgut: Stoßlüften? Nein, hier „rülpsen“ Häuser

Mal gut durchlüften – was wir in Deutschland mit der Muttermilch aufsaugen, entdecken die US-Amerikaner gerade und erheben es zum Trend.

https://www.swr3.de/aktuell/nachrichten/lueften-house-burping-trend-102.html?at_medium=social&at_campaign=%40swr3%40ard.social

#Luften #Stoßluften #USA #Trend #HouseBurping

Apparently* it is #GermanWeek 😅

If you are interested, as a German abroad I really like these two channels reflecting on (and reminding me of) life in #Germany:

Uyen Ninh
https://www.youtube.com/watch?v=K95cKz4dzEI
and
Liam Carpenter
https://www.youtube.com/shorts/LM9tHuv5cA0
#Lüften #Luften

#Gearmailteach

* The #GoetheInstitute says so:
https://www.goethe.de/ins/gb/en/spr/drm/gw26.html

@grumpy_copi erstmal 🇩🇪Dinge tun: #lüften

🫣

I'm still unconvinced that luften actually works outside Germany. Been doing 5-10 min opens in the bedroom at a minimum, but window moisture remains to an extent (they are old windows).

I do understand the air exchange concept though, that definitely helps in reducing in-home CO2 (which I've been wanting to track for a while)

Dehumidifier may be the better option here... also an air exchange system would be nice too.
I've seen some airex. that basically pull in cold external air into a chamber, then stop the incoming fan, before opening the outgoing fan and door to bring it into the house.

#de #germany #luften

Gerade ist der perfekte Zeitpunkt zu #lüften liebes #Kiel :)
#servicepost

Ich lüfte.

Irischer Nachbar: "That's a very German thing, isn't it? 🤔

#lüften

Eigentlich wollte ich gerade noch #lüften, aber https://on.soundcloud.com/3TLlTwmZJp9EO4FfD4

Mayke [21/31] - To Lüften, or not to Lüften? That is the CO₂ question. Let’s check the ears :iso7010_cat_ears:

https://martinh.net/hacks/katzenohren-sto%C3%9Fl%C3%BCften/

(yes I am still pretending it is May)

#Mayke #Mayke25 #Retro #CO2 #AirQuality #lüften #querlüften #stoßlüften #ISO7010 #ISO_7010 #katzenohren #CatEars

Richtiges #Lüften ist das A&O bei #Extremhitze #Hitze. Es macht wenig Sinn, zu lüften, solange es draußen noch heißer ist als drinnen. Sobald die Wärme weg ist, kann man die Fenster wieder öffnen.

Ich sehe immer, dass Leute ihre Fenster offen lassen. Bei mir ist das deutlich kühler in der Wohnung.

So, morgendliche Lüftung beendet. Immerhin hat es etwas gebracht und im ganzen Haus sind es höchstens 22,5 Grad (Dachgeschoss). Nächste Nacht soll die (Außen)Temperatur laut Wetterbericht angeblich nicht unter 25 Grad fallen. Ich weiß nicht, wie ich das überstehen soll. Ich bin für Hitze nicht gemacht, in den 1960ern war es deutlich kühler! Werde gleich zum Markt und zu Rewe radeln und dann die Wohnung nicht mehr verlassen.
#Hitze #Lüften #GlobaleErhitzung