12000btu or 9000btu inverter unit air conditioner

[alkit]

Hi,
My room is measures 3.6mx3.6m
With 1 window (north facing) 2mx1.2m

I need to decide between a 9000btu or 12000btu inverter unit.

I gather 12000btu would be better and I'm happy to go for it as it doesn't cost much more. The question is - as it is an inverter unit, it always is running (as far I understand).
Therefore, will the 12000btu use more electricity or make the room too cold?

Thanks in advance for the advice

 

[reactor_sa]

Rather too big than too small, the inverter will only use the power it needs to keep set temps anyway.

 

[DJ...]

12000BTU seems like complete overkill for that size room...

 

[TheJman]

Hi,
My room is measures 3.6mx3.6m
With 1 window (north facing) 2mx1.2m

I need to decide between a 9000btu or 12000btu inverter unit.

I gather 12000btu would be better and I'm happy to go for it as it doesn't cost much more. The question is - as it is an inverter unit, it always is running (as far I understand).
Therefore, will the 12000btu use more electricity or make the room too cold?

Thanks in advance for the advice

Worth while checking on the actual unit you intend to buy, I know the guy at Samsung said something about the warranty being void if you don't install the correct unit - worthwhile checking it out

 

[Iroiro]

9000 btu should be more than sufficient for that size room. An inverter only runs at the level required, so if you oversize it will only ever run at part load. The unit has a thermostat so it will only cool the room to the temperature you set it at.

 

[SauRoNZA]

No it isn't always running, it's just recommended to get an inverter if you plan to run your aircon all day as it's then cheaper to have an inverter unit.

Normal Aircon : Compressor outputs a flat temperature and the aircon then switches itself on and off based on the room temperature or adjusts the fan speed to maintain the room temperature. (Same reason it's no more or less economical or different to put your aircon as low as possible to quickly cool the room down...as the air is the same temp regardless).

Inverter Aircon : The compressor itself regulates the temperature as is required by the aircon unit and therefore the room itself. Because of this very action it is therefore more economical but the trade off is that it's only really so if you were running the aircon for long hours.

If like me you only plan to switch it on for an hour at a time to cool down the general area then a conventional unit will be just fine. If you work from home or something where you'll run it 12 hours of the day then an inverter will be cheaper.

 

[CamiKaze]

12000BTU seems like complete overkill for that size room...

+1

Even a 9000 BTU is a bit overkill.

 

[agentrfr]

12k BTU is a little overkill for that room, but you can't go wrong with too big an aircon - the inverter will regulate the temperature and use the appropriate amount of electricity. Larger aircon units tend to have better efficiencies than smaller ones in general (though you should check for yourself between the two options. The aircon with a greater Coefficient of performance COP is the better one). Additionally the larger unit will cool or heat the room quicker... so if the prices are similar and the COP is the same or better for the bigger one, get the bigger one.

 

[The_Traveller]

What's the kWh ratings on an inverter? I know each model is different, so if I'd opt for an inverter kind , entry level?

 

[jambai]

Out of interest,do you think these units are difficult to install?

 

[alkit]

12k BTU is a little overkill for that room, but you can't go wrong with too big an aircon - the inverter will regulate the temperature and use the appropriate amount of electricity. Larger aircon units tend to have better efficiencies than smaller ones in general (though you should check for yourself between the two options. The aircon with a greater Coefficient of performance COP is the better one). Additionally the larger unit will cool or heat the room quicker... so if the prices are similar and the COP is the same or better for the bigger one, get the bigger one.

Thanks for the helpful reply!

Turns out the COP of the 12000btu is 3.71 and 9000btu is 4.01

Does that mean I'm getting almost 10% more efficiency from the 9000btu?

(They are both the same brand - Daikin inverter)

 

[alkit]

Out of interest,do you think these units are difficult to install?

I would only recommend installation by a qualified installer. I don't think warranty is covered if you try do it yourself, but I could be mistaken.

 

[alkit]

Out of interest,do you think these units are difficult to install?

9000 btu is max 2.5kW and 12000btu is max 3.5kW.

A friend of mine tested his - when coooling fully, his 12000btu runs at around 1kWh. When keeping temp constant, it goes down to around 0.25kWh. Very efficient...

 

[Hemi300c]

For the price difference, normally a few hundred rand, rather go for the 12K BTU.