To BEWARE,
All brands will allow you to on all 4 units at any one time. No issues about this, just that the total btu capacity will be limited to the max btu rating of the compressor.
So if you use all 4 at the same time often, best to get the higher powered 40k btu compressor, if not, the 30k will serve you just as well if max you on 2 - 3 units at one time.
You should be looking at the max capacity instead of the rated capacity.
Thanks terumo. This is very helpful. I was reading up the datasheet and noticed that cu will allocate a predefined value to a certain set of configuration.
For example taking York CU YCHMYC028 with 12K + 18K configuration. The total FCU BTU with this config is 30K while the CU output only 26.7K when the max is suppose to be at 31k. Looking further datasheet, as this is a system 4 CU, only when utilizing all 4 FCU, will push the CU to the limit. Any idea why is this so? I mean, why cant the CU just allocate the max possible to any config?
Another question would be room sizing. I have been to Daikin proshop and check out my floor plan. Say one of the area is 322sqft which is rectangular in shape with a height of 2.65m. I was told i need a 22.xK BTU FCU. when i check out most of the website, it states i would need merely 12K or less. Adding more people (600BTU/pax) or adding on the kitchen area (which i need to as i have hacked down the wall) will still stay well below that 22K suggested.
Base on your knowledge, how can i best judge and size it correctly with the fact that sometimes there will be open and close doors, sometime between 6 to 12 pax, north-facing hence, considered normal, etc.
Pardon me for my long message as i believe im very near to buying the correct Cu capacity and correctly size my flat up for proper configuration.