Replacing a Built-In Aircon Unit

[Crash999]

I'm not sure of the correct aircon terminology but I own a condo that has three aircon units, one for the living room and one for each bedroom. The units themselves are in the ceiling on the balcony and vent into each room via vents that look like this:

Ever since I bought the unit I noticed that the living room which is a large space cools much more effectively than either of the bedroom units. They make a lot of noise but at night only ever get cool around 2-3am after running full bore for several hours. Turning the fan up only seems to make more noise but doesn't speed the cooling up noticeably.

As it has been that way since the unit was new I was thinking that the two bedroom aircon units are maybe insufficient for the size of the space and the heat it receives in the afternoon. But this is Thailand, and it's hot, so I thought maybe this is the best one can get.

But over the weekend I visited my parents-in-law and stayed in their guest room, which had a small split-type aircon unit on the wall. I was bracing for a warm night but the tiny thing was pumping out gloriously cold air and I had to turn the thing down.

So this has made me think I should replace the aircon units I have in my condo.

Given this is a built-in thing and not the split type you see everywhere, where do you guys suggest I should start for looking at replacements? When I've visited department stores I only recall seeing the split types, though may very well have missed other available types!

Thanks in advance for any help!

[wpcoe]

What you have is not so different than other "split-type" air cons. What you have is a split-type air con in a different form factor with the evaporator/fan unit concealed above intake vent (bottom) and behind air outflow vent (side) instead of being mounted on a wall as a nicely-encased-in-plastic unit.

When the last time the units were cleaned/serviced? They could just be dirty and/or low on refrigerant.

Consider cleaning/recharging before taking a look at replacing them with higher cooling capacity (BTU) units.

[IMHO]

OK, first off, this is referred to as a low-static-pressure duct type (so you are asking for the right thing).

These are readily available from most of the specialist AC brands, but beware that these types have very long product life cycles and most that are on sale right now are very old-tech, using R22 refrigerant (which you can't re-gas after 2018) and are horribly power inefficient.

Saijo Denki and Daikin both make units using r410a refrigerant, and designs with Inverters - concentrate on these.

[Crash999]

Thanks so much guys for your answers. Sorry it took me so long to respond!

Wpcoe, the last time I had them cleaned was 6 months ago but in the past it hasn't made any noticeable difference. It is really necessary to refill the refridgerent on such units? I read somewhere that aircon units were closed systems like a fridge so unless something is leaking/faulty there should be no need to fill them up.

IMHO, thanks for the terminology and links. I'll check to see what is currently installed and focus on ones using r410a. Does it make sense that it may be necessary to replace with a more powerful unit? What I'm worried about is there could be something inherently wrong with the design of the unit or ducting in the unit causing the issue, so replacing them doesn't do anything. Given the demand for aircon in Thailand it seems there's a business opportunity for someone to do this sort of analysis for customers.