Hi, I was considering installing AC in our 3.5 room apartment. We are renting, so that must be a mobile one (no fixed installations).
Now, you might know that "monobloc" mobile AC units (like this for example) are actually very bad: they use indoor (cooled) air to cool down the hot gas, and then they vent outside this air. This displaces cool indoor air and sucks hot air from outside, e.g. by door fissures, chimneys etc. Absolute garbage, basically a thermodynamic scam.
Fixed AC units do not have this problem, because they separate the (indoor) cooling unit from the (outdoor) hot plate and fan. Unfortunately they are, in fact, fixed.
So, I just found out that there exist indeed mobile "split" solutions, like this one for example. But I actually only found THIS particular model, not much variety around, at least on the Swiss market. This thing is expensive and bulky (50 kg).
Do you have any experience with these kind of AC units? Where would you recommend to shop?
Thanks!
I've been told that the best, simplest and most effective mobile option would be a window-based unit like this. Its one single unit so no installation other than perhaps some brackets for the outside and blanking curtains either side.
Unfortunately sash type windows are rare here, so it may not work for the majority of us.
We have one of the units in your link, Italo, bought during the awful heatwave of 2003.
Yes, it's bulky, yes, it's a pain in the proverbial to install - but it gets the job done.
OH rigged up a window frame thingy that makes an airtight seal - this is important because you put the condenser outside and the unit inside, joined by a cable. Our old model is all in one piece, you can't disconned the cable between the two - so for us, that cable has to go through an open window. It's a small opening, but nonetheless for a good seal - and of course home security - you have to securely close the gap.
I would hope that newer models have solved this problem.
But the good news is that our unit is still going strong 19 years later. (Knock wood, looking at the weather forecast. Edging towards 40? In Switzerland? Say it aint's so!)
Yes, it's a lot to pay for something you'll use only a few days a year. And likely not even every year. But on those few days, it's an absolute godsend. When it's 30 and sunny outside, our house heats up so quickly that it is soon unliveable. For those few days, I couldn't be without it.
Actually, I looked at your link and thought "wow, great price!' - as 19 years ago these units were double the price.
Well, the split you presented seems to still have compressor (the main source of noise) in 'inside' unit. This, while will be more effective and won't cause pressure difference will still be almost as loud inside as 'normal' units.
What I've seen in the past is the mobile AC where unit can be outside (eg. on Balcony) like such (it can be used also inside like normal mobile AC, just mount hose on the other side) :
This way you keep it all out and just keep cold air (pressure build up if apt is sealed will still happen). Last season I have put my traditional mobile one on the balcony and with some DIY so while uber-ugly it worked like a charm and inside was simply nice and barely hear able.
From an energetic (and money) point of view the most insane thing. Cooling down +30°C air ?!?
The traditional (in a US point of view sense) window mounted split units are highly efficient heat pumps (which can also be used for heating).
Hornbach has some with where the compressor is outside:
https://www.hornbach.ch/shop/Klimaan...ikelliste.html
well it's true if air outside is hotter then inside...
on the other hand, I prefer this than sitting inside with a really loud device and a headache
You posted a link to split ACs which aren't mobile and you are not allowed to install this in rented apt (and this is the case of OP)
Depends on the individual rental contract and renter as to whether it is allowed or not.
Two-part is the way to go, current units are not loud (they claim 57Db) and they are mobile, they have wheels (presumably to counter arguments about mobility). We bought a new one last year and we do not even have to turn up the sound on the TV when it is running.
Also bought from Fust, the new version of the one we bought 15 years before but no longer cooled. Foolishly I did not check if the hose between the two units was easy to remove like for the old one. Not a big problem, Fust sent along an engineer who disconnected the hose, stuck it through my predrilled 4cm hole in the wall, and connected it up again all for around CHF 200.
What model exactly (got a link maybe?) are you referring to?
I never saw those units that stay outside and blow cool air inside. I guess that's an option to avoid sucking hot air from outside, and also to avoid the indoor noise, but surely they must be extremely wasteful.
"American" style small AC units that are installed directly on the windows could also be an option, but as already noticed this kind of windows is extremely rare here, and in fact we don't have those in my flat.
Uhm, this is interesting. Did you drill the hole yourself? Is it even allowed to drill such a big hole without explicit approval of the landlord? (Livit in my case) Is it easy to close after you leave the apartment?
I own the apartment so it was no problem. My windows sit on a wooden beam so I just drilled through that.
In principle, it is no different than drilling a hole to hang a picture or wall lights that must be filled in afterward, just a question of scale.
I did repair such a hole for a friend who had his a/c in a rented office using one of those pressurised tubes of building foam.
Might be more complex for Minergie constructions.
Can you explain to me the logic of this? I have used monoblock AC units in my room for years and I can tell you with 100% objectivity and certainty that they DO cool down my bedroom a significant amount (eg: from 27+c down to 21-22c with no humidity). This means I can then actually get to sleep and even after turning it off the room stays cooler for some hours.
They be loud, they may be energy inefficient, but as far as I understand it cooling down a room to a significant degree is defined as having achieving their intended function, not as a 'thermodynamic scam'.
They work, but not as efficient as a split unit. The reason is quite simple: A single unit can only push out hot air through the hose into the environment. But where does this air initially come from? Obviously not out of the thin air. The only place where air can come from is from inside your room! Which means part of your precious cold air will be heated up and blasted outside.
Now, with a split unit (even those blocks mounted in the window frame) no air will be exchanged between the inside and outside. The inside air will be cooled down, while the outside air will be heated up.
The biggest issues, and not really clear for the consumer, is the energy label. An A+ single block unit is as efficient as a B rated split unit!
Or in numbers: A mobile single unit with A++ rating uses 800 W of energy to dissipate 2900 W heat . While an A++ split unit uses only 400 W to provide the same cooling performance.
Thanks but I am not questioning that a split is more efficient, I have had a split in the UK, but the OP made it sound like Monoblocks don't work. They definitely work to cool a room and they cool it well... for the eight or so weeks per year where they are needed.
I think people have unrealistic expectations of the low watt, CHF 399 ones they pick up OBI or Interdiscount. A beefier 12,000 BTU unit will do a good job in a reasonably sized room as long as you get the ducting right e.g. you're not poking the hose out of an open window.
Having these outside, unless in a very shady spot, will make them work much harder.
Such setup does work however, as I said last summer I DIYed same thing (with different mobile AC) and it was nice and fairly quiet inside.
I Agree you need to buy something decent quality. My duct is poking out of a window with the roll blinds down on top of it and a thick bath towel plugging the gap. Works like a charm and in 3 hours I have a crisp and cool bedroom.
At the start of Summer there are often some big deals on AC units. I got a beefy Electrolux in a nice black colour for half price (320chf).
Basically, you are cooling down the room where you install the unit, but you are actually warming up the rest of the flat, even if you don't realize it. But I admit it might make sense in some cases. For example, we realized that most of the heat in our apartment comes from computers (working from home), hence at the end we decided to install a monobloc unit there. It's suboptimal but we do what we can