Inverter Air Con

[lassebasse]

Hi, I am looking to fit 5 air cons to my new house and I have been looking at the prices (here in Udon Thani). Inverter air cons sounds very attractive but the price is like double compared to the traditional ones, at least for Daikin.

Is it realy worth it? How much should my electric bill go down with inverter compared to the old ones?

[stgrhe]

Advantage with Air Conditioner with Inverter Units

A basic conventional system has a basic 'engine' that is just like a motor car. This engine basically has two speeds, maximum speed and full stop.

These conventional systems use a lot of electricity in these types of motors because it takes a lot of energy to start a motor from zero. And when the room reaches the temperature that is requested on the climate control thermostat, the motor will turn off completely.

With an inverter air conditioning system, e.g. like Fujitsu, Daikin, or Mitsubishi Electric, the motors are designed differently. When an inverter is turned on, the motor will start up slowly so that it does not use a lot of power, then the motor slowly speeds up to full power on a sliding scale. This way the system uses much less power to initially start up.

As the system gets closer to reaching the set temperature for the room, the motor will start slowing down, again using less electricity. And as an added benefit, the temperature in the home will remain more constant, assuming the heat load has been done and the unit has been sized correctly.

The end result is that the motor does not have to completely stop and because of this it doesn't use a lot of electricity trying to overcome inertia trying to make the motor initiate from a complete stop. The typical savings with an air conditioner system with inverter compared to a conventional system is about 30%.

Air conditioners are a very good to use when compared to conventional systems provided the unit is not undersized. With an undersized system it is likely to consume about 10% more electricity compared to a conventional on-off type.

Edited: Font changed

Edited September 15, 2009 by stgrhe

[malcolminthemiddle]

Is it possible to convert an AC system from conventional to inverter type?

[trogers]

Sorry to divert a little from this post.

Has anyone used an inverter air-con from some makes other than Daikin?

I am looking to purchase 9 inverter air-con units in the next couple of months. Found that Daikin is not lowering their prices even though excise taxes has just been lowered.

[kamalabob2]

We are very happy with the Panasonic Inverter a/c unit in our daughter's room. The price varied GREATLY from shop to shop in our province. One place wanted more than full pop list, others only a small discount but in the end it came down to two independent shops lowering prices twice from original written estimates. The price printed in the glossy catalog is only a starting point, except for one dealer when I was shopping in 2008.

[trogers]

Is it possible to convert an AC system from conventional to inverter type?

Not worth doing as it would mean changing the innards of your condenser unit and electronics.

As to answering the OP's question - generally yes if you get the inverter at a reasonable price and if you use the air-con unit at least 8 hours a day. I have a Thai developer who swears on the savings in electricity bills he gets in his 6 bedrooms 2-rai home after switching to inverter AC units. You should be able to break even on the extra cost of inverter units within 3-4 years, depending on how heavy your family uses air-con.

[JimmyGreaves]

Sorry to divert a little from this post.

Has anyone used an inverter air-con from some makes other than Daikin?

I am looking to purchase 9 inverter air-con units in the next couple of months. Found that Daikin is not lowering their prices even though excise taxes has just been lowered.

Is that because they have already vast quantities already imported and have already paid the higher taxes or are the just *astards?

7 meter * 4 meter bedroom. 20cm Qcon facing N/E not much sun what btu do i need or does anyone know a good site for calculations as they vary by miles, gonna buy inverters for the my bedroom and wifes bedroom the guest no sure as will not be used full time

Edited September 15, 2009 by jflundy

[trogers]

Sorry to divert a little from this post.

Has anyone used an inverter air-con from some makes other than Daikin?

I am looking to purchase 9 inverter air-con units in the next couple of months. Found that Daikin is not lowering their prices even though excise taxes has just been lowered.

Is that because they have already vast quantities already imported and have already paid the higher taxes or are the just *astards?

7 meter * 4 meter bedroom. 20cm Qcon facing N/E not much sun what btu do i need or does anyone know a good site for calculations as they vary by miles, gonna buy inverters for the my bedroom and wifes bedroom the guest no sure as will not be used full time

28m2 less space of wardrobe (about 3m2) = 25m2 x .70 about 18,000BTU. Assuming ceiling height of about 2.5-2.6m.

I am using old air-con units (5 and 10years old) in my 2 spare bedrooms as I estimate they are only used max 2 months in a year from visiting relatives.

[JimSiam]

The Inverter units can be a waste of time, the time taken to recover the cost savings are a long time.

The are slower to cool a room due to the slow start design of the compressor, if you want to save money on cooling its better to insulate the house and use other methods to reduce heat like properly backed curtains, double glazing, awnings over windows.

[trogers]

The Inverter units can be a waste of time, the time taken to recover the cost savings are a long time.

The are slower to cool a room due to the slow start design of the compressor, if you want to save money on cooling its better to insulate the house and use other methods to reduce heat like properly backed curtains, double glazing, awnings over windows.

There are 2 train of thoughts:

- minimize use of materials and furnishing that absorbs and retain heat to the extend some promotes the ideal conditions of a metal shack...lol, reasoning, such space cool faster after sundown, and need minimal air-con.

- heavy insulation like cavity walls, double glazed or reflective glass, etc. This assumes much hours using air-con in the hot afternoons.

I prefer the middle approach - normal furnishing to personal taste, and open up door and windows and on the ceiling fan to vent off the heat of the afternoon before closing the windows and turn on the air-con.

[offset]

They also I believe are quieter to run on the motor unit because you do not have the start-up noise which might be important depending where you have to site the unit

[thaimite]

Although inverter units are great in principle i decided that as I use my units infrequently (a few weeks in the year) and some units for a few hours a day I would never recover the cost of the extra investment

[offset]

I think that I am going to need 3 unit in my house 1 for the master bedroom which will be an inverter type which I intend to run all day but at about 29C the other 2 will be normal types because they will not be used much you do not have to have all units the same It is not only down to cost the inverter types are known to last longer

[trogers]

I think that I am going to need 3 unit in my house 1 for the master bedroom which will be an inverter type which I intend to run all day but at about 29C the other 2 will be normal types because they will not be used much you do not have to have all units the same It is not only down to cost the inverter types are known to last longer

I think you should set temp to 27C as indoor temp in the afternoon would peak around 31C when outdoor is at 35C. You will need the AC unit to run longer to bring down humidity as well, not just temp.

[trogers]

Just to add, the greatest enemy of an efficient AC unit is smoking. Tar condenses and coats the metal surface of the cooling fins and pipes and easily collect dust , reducing heat exchange.

For smokers, best to make a smoking area at the balcony.

[offset]

I think that I am going to need 3 unit in my house 1 for the master bedroom which will be an inverter type which I intend to run all day but at about 29C the other 2 will be normal types because they will not be used much you do not have to have all units the same It is not only down to cost the inverter types are known to last longer

I think you should set temp to 27C as indoor temp in the afternoon would peak around 31C when outdoor is at 35C. You will need the AC unit to run longer to bring down humidity as well, not just temp.

I set the temperature in the bedroom to 29C at which I can sleep with no covers on and I use it as a cool room during the day

Edited September 16, 2009 by offset

[shubh]

The most important thing to look for with an air conditioner is the star rating. You need to work out what size you require for the task and then choose the most efficient model that will perform the task. There are three kinds of Energy Rating labels for air conditioners. The one for cooling-only models has a blue band of stars and a blue box for the energy consumption figure. Air conditioner outputs are measured in kilowatts (kW). As an approximate guide for sizing a room unit allow:

* 125watts (0.125kW) per square metre of floor area to be cooled in living areas;

* 80 watts (0.080kW) per square metre of floor area in bedrooms.

Inverter compressors are extremely quiet and up to a few decibels quieter than the same size non-inverter unit. This is of great benefit if you live close to your neighbors house or you have the outdoor unit located near one of your own bedrooms.

[Screws]

"if you want to save money on cooling its better to insulate the house and use other methods to reduce heat like properly backed curtains, double glazing, awnings over windows."

Absolutely.

MOST COST EFFECTIVE IN NEW BUILDING IS DOUBLE SIDED REFLECTIVE INSULATION UNDER FULL ROOF (EAVE TO EAVE) PLACED WHEN BUILDING.

Pardon the shouting - but many do not want you to hear the above.

You can survive with the above & a few fans - good for the planet and your pocket. No ongoing costs.

Even with air it is a great investment. I converted a house to above, & same time fitted split A/C. In the following year that I lived there I never needed to turn the A/C on.

[Naam]

The most important thing to look for with an air conditioner is the star rating. You need to work out what size you require for the task and then choose the most efficient model that will perform the task. There are three kinds of Energy Rating labels for air conditioners. The one for cooling-only models has a blue band of stars and a blue box for the energy consumption figure. Air conditioner outputs are measured in kilowatts (kW). As an approximate guide for sizing a room unit allow:

* 125watts (0.125kW) per square metre of floor area to be cooled in living areas;

* 80 watts (0.080kW) per square metre of floor area in bedrooms.

Inverter compressors are extremely quiet and up to a few decibels quieter than the same size non-inverter unit. This is of great benefit if you live close to your neighbors house or you have the outdoor unit located near one of your own bedrooms.

inverter compressors are not quieter than other compressors when the demand for cooling capacity is 100%. only when the load is less the slower rotations cause less noise. moreover, since years conventional compressors generate less noise than the fan of the condenser unit. anybody with a modern unit does not have to fear that the neighbours will be annoyed unless a 36 or 48k btu/h unit is installed.

[Naam]

The Inverter units can be a waste of time, the time taken to recover the cost savings are a long time.

The are slower to cool a room due to the slow start design of the compressor, if you want to save money on cooling its better to insulate the house and use other methods to reduce heat like properly backed curtains, double glazing, awnings over windows.

bring on more technical jokes please!

[Naam]

Is it possible to convert an AC system from conventional to inverter type?

not possible. an inverter compressor runs on DC (direct current), a conventional compressor on AC (alternating current).

[Naam]

note to myself: why the eff do i still waste my time and read the technical rubbish churned out by people who possess a wealth of technical "NO idea"?

[frenchFARANGbkk]

Any price comparison of Daikin Mitsubishi Panasonic inverters aircons ?

Thanks.

[trogers]

Any price comparison of Daikin Mitsubishi Panasonic inverters aircons ?

Thanks.

Had the following quotes:

12000 Btu

Samsung AS13ELN conventional 15.300 Baht

AQV13AWAN inverter r-410a refrigerant 21.000 Baht

Daikin FTE12JV2S conventional 16.500 baht

FTKE12GV2S inverter r22 refrigerant 26.000 Baht