Get cheap and cheerful single-hose mobile air conditioning unit. Get EDEKA bucket for condensation. Other buckets probably work fine as well. Get old office chair, cut it down and install a wooden base. The idea is to lift the aircon up (shortens hose length, cools not only the floor but the upper half of the room as well)

Now the crucial part: single hose aircon units are crap because they create "negative" pressure in the room they're supposed to cool. This draws in hot air through any gap. The aircon also uses some of the indoor air (that it fights very hard to cool down) to keep its compressor/refrigerant cool, and then it dumps that air out through the hose (hence the "negative" pressure).

With the help of a 3D printer, the aircon can be modified to feed it outside air for the compressor/refrigerant instead of wasting precious cooled indoor air. Absolutely mandatory modification.
Second hose needs to be bought separately btw. Or if you have the spare change, just straight up buy a dual hose unit.

Also crucial: most aircons come with a useless window adapter that works great only if you have US style sliding windows. For the tilting/rotating windows common in Europe I recommend to get a wooden plank and create two cutouts for the hoses. Depending on your woodworking skills you can cut the plank down to exactly the right size to make a perfect seal with your window frame. If not, the 3D printer comes to the rescue.

Dangling the hose out of the open window on the other hand is perhaps less than ideal and you might be better off donating money for a good cause rather than wasting it on the electricity going into your AC if you cannot fabricate a good seal.

The pros:
*Very cheap DIY setup
*Increased efficiency compared to single hose system, mitigates "negative" pressure and influx of hot air
*Compliant with local laws: aircon is completely indoors, wooden plank is obfuscated by outside blinds, no noise pollution to neighbors
*1000 W unit manages to cool approximately 20 m² bedroom by about 5 degrees within 1-2 hours. I turn it on at 8 pm, so that the bedroom is at a nice cool temperature around two hours later. Room stays cool long enough to fall asleep even with AC unit turned off.

The cons:
*Looks like a DIY job because it's a DIY job
*Efficiency is probably still quite bad compared to proper split-system AC unit, but since we're not allowed to have those…
*Need to remove and reinstall wooden plank in window frame every day.

And there you have it. That's how to stay cool during the surprisingly hot summers (that we have since a decade now, but I guess we're all still in denial).

Feel free to copy and improve!
And remember to empty the water bucket regularly.

by This_Assignment_8067

19 comments

  1. currently considering the same.
    worried that the hot side fan is too low power to work efficiently since with a single hose unit it’s designed to use as little air as possible to pull in as little hot air as possible. my guess is that this lowers efficiency significantly and the added restriction of using a hose makes this even worse.
    did you do any measurements about how the efficiency changed after your modification?
    wondering if adding another inline fan to the intake hose would make a big difference or if the internal fan can be modified to run at a higher rpm

  2. The wood cutting/3D printer part of the only thing kinda off putting because it’s tedious or expensive for those without the time or know how. Love it though

  3. Window AC-units have finally become a thing in good ol’Switzerland?

  4. that’s why they don’t allow ACs here, so you problem solving guys will solve the cooling problem for the whole world

  5. You talk about it but could you show us the 3D printed solution in the back?

  6. It is beyond my understanding why those things are not build that way to begin with.

  7. Wrong you get a split unit, like the one from Midea. Works better, is quieter and more energy efficient. You‘re allowed to use them.

  8. Meh. A Portasplit will consume 350-500W on the lower settings and still cool things sufficiently at much lower noise levels.

    Ofc it’s barely available and has a 25% markup over the standard price.

    Next time around buy your gear in winter and not during the peak season, it will be much cheaper.

  11. Nice. But how to do the missing part when we don’t have a 3d printer?

  12. Just a question, if I understood correctly, you are now cooling the compressor with hot air? Doesn’t that drastically reduce its lifespan?

  13. How is the plank affixed at the window? And how do you call the plastic thingies in the plank/where do you find them?

  14. Problem is i live right next to a busy cantonale. 

    I cant just have my window open like this lol

    Fan it is for me 🙂

  15. Aren‘t the intake and outlet hoses too close to each other?

  19. On my aircon, I wrapped the exhaust pipe in reflective duct insulation. It really cuts down the radiant heat that thing puts back into the room.

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