just to add: not just outside temp is important. you should also consider how well insulated your room is, how many people usually occupy it and what desired temp you want to chill down the room to.

in a well insulated room, a 1 HP aircon can easily handle a 25 sqm room. however if there is lot of traffic through the room (i.e. moving a lot of chilled air out) or a lot of people inside the room then you might need more power. same goes for equipment in the room that generates heat (PCs, lights, fridge, whatnot).

unless you know precisely how the room will be utilised it will be hard to give a good recommendation for the size of AC required.

FYI: 7,5 HP of a/C capacity *can* easily cool 550-650 cubicmetres of air to actual 25°C in a 3-5 person household if the rooms are insulated and windows ducted in normal malaysian climate (also in hot season!).

very specific question. what's sure: R22 is beeing phased out because it harms the ozone layer. that for me is enough reason no to use ACs with R22 and i dont.

now to your question: R401A tends to be more energy efficient than R22. if i remember correctly by 10-15% but i really dont have the supporting figure at hand anymore. i looked into this around 4 years ago when i changed my ACs to 401A inverters. i found an interesting read on the issue here:

https://docs.google.com/viewer?a=v&q=cache:...zusFVDI_EZB-DUg

No real time on off timer

Just remember, never it is cold air go out, it is how to preven heat from coming in. Check all heat source including all electronic gadgets, windows, etc... Heat transfer always from hot to cold...

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Added on April 4, 2012, 9:33 am

I would say R410A its just environmental friendly compare to R22. Its all about gas characteristic.

very specific question. what's sure: R22 is beeing phased out because it harms the ozone layer. that for me is enough reason no to use ACs with R22 and i dont.

now to your question: R401A tends to be more energy efficient than R22. if i remember correctly by 10-15% but i really dont have the supporting figure at hand anymore. i looked into this around 4 years ago when i changed my ACs to 401A inverters. i found an interesting read on the issue here:

https://docs.google.com/viewer?a=v&q=cache:...zusFVDI_EZB-DUg

In some country, they stop using R22 for new equipment, but use difference direct replacement gas for same identical machine, even same copper. Think in global market there are few direct replaceable gas for R22 without modifying the HVAC.

My friend been bring some of difference direct replacement gas via Singapore for testing. All he can say, is hell hard to bring in gas to Malaysia, lots of restriction and special permit... you know what. The loosing end is the customer.

He tested some, and seem to have good feedback. But all he can do is just small quantity for testing.

R410A in technical analysis is not very efficient at higher temperature.

Does R410a save more energy than R22 ?
Does Daikin Inverter air cond with R22 save as more energy as other Inverter air cond with R410a?

R410a gas is not about improve or anything relate to aircon. It is enviroment friendly gas where related to ozone. The R22 is going to absolute and later will ban from using once gov impose on it. When fully change to R410a.

Thanks for the info, i do recall something about 5/8" my friend told me. If not mistaken many will use 1/4" & 5/8" for 2hp and above.

Plan to install Mitsubishi 2.5hp aircond.
Any one know what the size for the piping??

1/4" + 5/8 for basic model

Mitsubishi Mr Slim consider as basic model??

Nope, Mr Slim is a series and got 3 ranges for Mr Slim,

Basic>Standard>Deluxe

So the pipe size for these 3 ranges will be different, right??

Plan to install Mitsubishi 2.5hp aircond.
Any one know what the size for the piping??

what model u r using? my mr slim remote got real time on off timer

Searching for a 2 hp aircond. i heard inverter ones cannot use the currwnt piping..?

Just install my Daikin 1.0hp Inverter.. Happy to it! Not fully tested yet, but it so quiet.. I buy RM1180 each. Price ok?

Daikin one can use old piping