Yes, I did search before asking 🙂
I recently moved into a new apartment but sadly the bedroom doesn’t allow for installation of a proper aircon unit, which leaves me no choice but to use a portable one.
I’m trying to find a good one, and it seems there are many decent models available in the west, but here for some reason I can’t seem to find one that fulfills the requirements.
* No water outlet – it should dump the water it takes from the room into the heat exhaust so you don’t have to go and empty the water every few hours.
* Double hose for outside air – i.e. it doesn’t create negative pressure in the room which reduces power efficiency massively, but instead takes air from the outside and then dumps it back out.
* Relatively quiet to be able to sleep in the same room.
Maybe I’m asking for too much, but all 3 of these functions are fulfilled by any normal air conditioner, so I’m hoping there might be a portable one that fulfills at least 2 out of 3…
6 comments
I’ve never seen a portable unit. I just keep my living room aircon on and have a fan to blow it through the open bedroom door.
I might be misunderstanding your question, so ignore if so. But are you asking about [spot coolers](https://www.tansu-gen.jp/products/79800001?gclid=CjwKCAjwrNmWBhA4EiwAHbjEQDfYKBhSKAg4mh6glwkycu2A6RGbr2LnfRbPNQdNc9zvruOpu7kD5xoCcQsQAvD_BwE)? Air conditioning works by moving heat from cooler areas to warmer areas, it does this utilizing the energy absorbed/released by phase changes of the refrigerant in a condensor/evaporator. Compressors force the phase change by creating pressure differences, and fans blow air over the coils to transfer the heat. And this is why spot coolers are pretty limited in their usefulness.
When your evaporator and condensor are both in the room you want to heat/cool you’re already fighting a losing battle. It’s why split units are predominat. Having the warm air exhausted outside will help, but this will require a fan that creates enough static pressure to exhaust the air through the duct (not going to be quiet anymore). And if you want to avoid creating negative pressure by pulling in outside air, you’re going to require far more cooling capacity than a typical split unit would need for the same space, as a split unit just recirculates same air over the coils again and again, progressively cooling. Your task now requires bigger compressors, that is more noise and even more heat being generated inside the space you want to cool.
Regarding having the condensation evaporated into the exhaust, that’s and interesting idea, but you’d need as big an area evaporator pan as you could get, this unit is no longer going to be small. Best you can hope for is a drain hose (by the way, dumping condensate into the exhaust isn’t standard in AC in Japan at all, it’s always drained).
Spot coolers basically do exactly what their name implies, make a single spot feel cooler than the surrounding. They’re not a realistic split unit replacement as nice as that would be. A [window unit](https://item.rakuten.co.jp/e-kurashi/64378/) be more like what you’re after?
When you say “doesn’t allow for installation of a proper aircon unit” do you mean that the landlord doesn’t give you permission to open a hole in the wall and install a normal split unit? And leaves you with only one 15×50 window?
Have you checked aircon units for RV campers? Like [this one](https://www.navic.cc/clecool7) for example.
As far as I know in a situation where you can’t do construction, people instead get window-mounted units (窓付けエアコン). They clip or attach to your window with a frame that can be removed so you don’t need to make any holes. Unfortunately, most of these units are pretty loud, but they still work well enough.
I had to go the portable route myself for a room in my house.
It’s a single hose unit with a drain hose out the bottom.
You’re not gonna find a proper one in Japan.
Now here’s where things get interesting.
I grabbed an aluminum tube at the hardware store and a sheet of craft foam. Made a cover for the intake that attaches to the aluminum vent hose and ran the tube to the window. Then I used some more foam to put in the window below the exhaust vent. Attached the tube to the window. To get around the issue of the drain hose, I just popped the whole unit on a metal shelf I got from Daiso and ran it under the intake hose and out the window.
It’s not pretty but it absolutely works.
How about cutting a piece of wood or something else exactly the size of that thin window?
Then you make some holes through that wood for a split AC system.
You’re not making any holes through the walls so the landlord will never know.