I had the same dilemma last year when i was choosing air cond.

What I was told by the air cond technician is that, unless you on the air cond for around 10 hrs or long periods of time, there is no difference between them.

Because from what I understand, inverter saves electricity by maintaining the temperature through constantly cooling and running at low power.

While non inverter air cond maintains the temperature by cooling it down to the desired level, stops cooling and will only start cooling again after the temperature rises to a certain level.

This act of cooling and stopping takes up a lot of electricity, as more electricity is needed to restart the cooling as compared to running the cooling at low power continuously.

Thats what I understand, please correct me if I'm wrong...

So if you're just using for your living room, there should be no need for an inverter. Plus the price difference between inverter and non inverter is not exactly small.

As for brand, my recommendation would be PANASONIC. Its more expensive compare to the rest but each of them have lasted at least 10 yrs before breaking down and requiring extensive repair. When that time came, I just bought a new one...

Currently for my house I bought 5 air cond, all PANASONIC. 3 unit 1.5 hp and 2 unit 1 hp. 2 unit 1.5 hp in the living room and 1 unit 1.5 hp in the master bedrooom. Electric bill stands at around RM200-300, no tampering of my power meter.
My neighbor using dunno what brand, dunno how he use, he is complaining of paying RM800 a month.

And please take note, normal house circuit only can take total 4 hp of air cond running at any one time.

For inverter to be cheaper than the equivalent non inverter, it must fulfill a few condition:-
Use more than 8 hours a day. Less than that the savings that you get cannot cover the difference in cost.
If you do not fulfill condition 2 and 3 below, you can run it 24/7 continuously non-stop and still not save a single sen of electricity. In fact, you will actually spend 10% more on electricity compared to non-inverter because Inverter have to convert AC electricity to DC and there is a 10% lost.
2.) 25-27c. If you go too low, the inverter will be at maximum power all the time and you will not get any benefits from it.

3.)Appropriately sized. Similar to above, if you use too small of a aircond , then it will be at maximum power all the time to cool your room and therefore no saving benefits.

Generally people will use inverter for bedrooms and non inverters for living rooms.

Here my actual experience. First aircon is panasonic non inverter 1hp using 8hr for sleep. Bill average rm110. Run  about 8-9yrs before it finally spoil.

Replace a new Panasonic inverter 1.5hp. Same usage. Bill cost me average rm70. Already running 5yrs till now.

First yrs already get back my return compare non inverter. Base on the last time bill and current bill. 5yrs now I already save rm2400. The save Can use for service the aircon many many time.

No matter how many hr using, it still save. Long or short. Sometime I find you guy are very slow to adopt the technology which is already more than 10yrs old. And still undecided it now. 

My room is about 180ft2.

One thing I learn is, size the aircon according to the room size. Not your wallet size.

It is not just the inverter. The size of the aircon too.

The start stop is depend on the weather. When there is hot weather, the aircon run more. I can tell because I put it into auto mode.

The amount $ I save is already can buy another unit. So why you guys still doubt about inverter?

can advice how many HPs and Inverter or not for my living room?

18000btu/h per unit is too much la. Get 2 units of 15000btu/h AC. Total 36000 btu/h is overkill. Inverter or non inverter you look at how is your usage. 9000btu/h equals to 1HP.

My calculation goes to a slight bit less than 32,000 btu/h. It is really his preference. For me I will go for 2 units of 15,000 btu/h unit. I personally believe that it is enough. Optimise what I need and save on my wallet.

Of course there will be. 

1. There are constant people moving in and out of the room. - We do not know that. How often do we see people go open the front door of the living room? I suppose more often the bedroom
2. Lots of sunlight coming into room - My calculation is facing east in the evening Sorry. I don't understand. What do you mean by only facing east in the evening? What about morning?
3. More people in living room compared to bedroom. - My calculation is based on 4 people in the room
4. Extra heat from big Plasma TV - My calculation is based on the usage of 600 Watt electrical appliances
5. Huge Class A heat generating amplifier for HiFi - I did not consider that

Huh? Lots of people going in and out from your living room? Only hotel has that in a lobby. Your occupants don't sit around the house but go out and in all the time? I go in and out from my bedroom quite often. More often than going out from my living room to my porch.

During the morning, heat from sun is lesser than of the evening. If the living room is facing the east, during sunset, the heat will go to either the kitchen or else where. Living room will be spared. I put the room facing east as a buffer, since the best/ not hot situation will be the room either facing north or south (sun will go from east to west without direct light going into the house). Worst case will the room facing west, and I hope that this living room is not.

At full load it is. Some inverter with different brand runs more than 70, some less.

In my view, there is no best inverter, no best AC. All AC works with the same principle. It is not like your AC can fly. ACs are backed with brands and so called recommedations. All AC has fair share of problems. Some ones recommendation is another condamnation.

You can only bet. Bet that it will last, bet that the catalogue value is what it claimed to be, bet that the service or installer knows what he is doing, bet that the additional functions actually works the way you wanted, bet that the after sales service is good.

How to bet, place your bets on the big brands. Not something like Media, i, Koolman.

.......I lost of words with this explanation.

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Added on June 28, 2012, 9:50 pm
I am pretty sure that you have already select your brand. So why not go with it leh?

York is not Daikin, Daikin is not York. Daikin under Daikin Corp. York under JCI.

Yup, OYL Group was acquired by Daikin at that time. The only link they have with York is Group Associated and OYLC. GA is a sales entity/ sales office. They sell York Room Air Cond and Package Air Cond in Malaysia. Another subsidary of OYL Group is OYL Condair. They are the manufacturer of Chillers, Air handlers, fan coil, mainly on the commercial side of Air Conditioner under York brand, because this subsidary is a joint venture between OYL and JCI. Daikin does not control the manufacturing side of York RAC. York is under Johnson Controls International.

I believe that there is no technology transfer between Daikin and York for the RAC. Generally, the York Non Inverter is much better than Pana. Cheaper too. Inverter type, York loose out a little. I have no idea why the EER is poor for a certain range. There can be the development direction. So pick the best out of the brands. Don't just stick to one brand.

Changed my old 1hp National x 2 units (7-8yr old) to Panasonic Econavi Inverter.

Usage : 9-10hrs/daily x 2 units

Previous TNB bill : RM350-450/monthly
Now : RM250-280/monthly

Months after that, TNB came over to check meter, suspect I temper my meter..

So, I would say. It's really works.

I'm not air-cond seller or promoting anything, just a honest & satisfied user.

Haha , i iz nerd .
So go for inverter or non?

Its a bedroom. I only turn on the old air cond when need and only for 2-3 hour to make sure the room is cold enough and turn off already 

Since normal aircond use plenty of current instead of inverter, thats why I just use for 2-3 hour, just to ensure the room is cool enough to sleep with  

I see. now I get the picture    Need to hunt some brand out there. at my area most of then ada sharp lg pana samsang je. daikin M e they dont carry