I need 2 aircons for 2 adjacent rooms. one is 32sqm and the other 16 sqm.

Neither have any aircon currently installed.

Can I buy 2 aircon units to run off a single outside box (compressor?) ?

Also, they are 7 stories up with no balcony, just big wide windows, but no bracket to hold the box.

What do aircon companies do? Hang out the window on a harness and drill and bolt in the bracket to hold the box??

Thanks very much.

What is allowed on your building - you can not just do as you wish. Yes they do make such two air handlers on one compressor systems but most buy separate units. This really should have been part of the condo purchase discussion.

Is it possible to buy one aircon unit first, and then at a latter date add a second unit to the same box?

Or does a box designed for 2 separate aircons need both connected to run?

They are designed to serve two units - might be able to buy new compressor to serve current and additional inside air handler - but as said few people buy such units here so not sure how they are made. The inside unit has a bracket attached to wall but needs access for electric/gas from/to compressor and water drain.

Sure. Thanks.

It's the bracket for the outside compressor that might be an issues as it is 7 stories up, and would require them hanging out a big window to bolt it into the wall below it.

Not the easiest thing to do.

The big thing with be the condo regulations - am sure they can take care of installing just about anywhere if legal. But will also need water drainage. How have others done?

Yes, the condo next to mine has two compressor boxes under their windows.

Fujitsu aircon make those two ventlators unit on one compressor, you might want to call them and ask about their experience...

I had a multiple split unit back in Europe. When it was first fitted we only connected one internal unit and the connectors for the second were blocked off. Then when the second internal unit was fitted a year later they just fitted the new pipes and re-did the vacuum in that part, and then charged it up with gas. It all worked fine and didnt affect the first internal unit at all.

As far as the condo question goes, walls dividing units are normally common property and so you have no right to drill through them even if you own both sides. Normally all modifications (even those entirely situated inside one unit) require advance consent from the juristic person though this requirement isnt always applied in all buildings.

Thanks for the replies.

I have checked with the building and as it is a top floor condo with a big loft above it, they said that the compressors usually go in the loft, and then just come down through the roof to the AC units in the condo.

There might be some guys that a property developer I know. I would ask for a quote of 2 compressors and 2 aircons, and 1 compressor and 2 aircons.

Thanks.

Two inside units running off one outside unit (compressor)...sure it will work but the system/electronics has to come designed that way.

Just noticed a poster in an MRT station (Phraram 9) for a Mitsubishi system that can run more than one wall unit from a single compressor, so maybe check out their website.