Checklist when buying a new aircon

Whenever you look at prices do check out:
- type of aircon, whether it's the latest
- the compressor, is it the right match
- type of components supplied - tubing, pipes, insulation
- does it cover replacement of existing pipes
- will they run in the walls and conceal it?
- is it the same cost for condos / landed (typically landed costs more due to more pipes and the concealment)

If you are looking out for energy consumption, bear in mind the balance of needs:
A Five Star Energy Rating may mean the aircon is less able to cool especially if you have multiple air cons running at once.

The compressor size is important, make sure it's powerful enough.

I sacrificed star rating to get an aircon unit which is able to handle the needs of a living room,  and I don't usually turn it on there, except when there are guest. However, in my bedroom, I used a five star unit for energy since it's probably going to run all night and daily. 

- however, if you have a big hall, you do need a larger BTU. If you use too small a compressor or blower, you end up shortening it's life from stressing it too much
- consider where will you run the pipes, and if you need two blowers in the living, dining area or any other space that is larger

There are many brands, and many functions. So apart from the price, and the energy rating some other factors:

- size of the units, will it fit in a tight spot, eg in a cove / pelmet
- does it filter out dust particles? Eg Mitsubishi Starmex and Panasonic can filter out the PM 2.5 particles
- do you really need the wifi and automation? Some folks will want functions like turning on their unit remotely from work or on the way home
- how's the warranty and repair, are parts cheap? Does your aircon man know how to handle it, especially if it's not a popular unit
- access for cleaning
- getting the same brand around the house means you have a few remotes to go round
- is the noise level ok?
- what kind of coolant does it use or can the new aircon use your existing pipes

Siting the compressor and blower also matters. Don't put it too close to your bedroom window or just outside your room, it may be very noisy. 

If you are concealing the pipes how will they run, and how far is the compressor from the blower - the further away it is, the less efficient it is. But try and site it on an easily accessed spot, so the vendor does not charge you more for cleaning.