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Inverter air conditioning units may be a bad choice for many in the Philippines and other tropical locations, but you won’t hear that from air conditioning salesperson or in the glowing advertisements for them.
Inverter units are highly promoted, cost a great deal more than conventional units, but supposedly save enough money to easily repay the extra cost in months. There are a number of problems with this rosy view of inverter air conditioners.
Inverter units use advanced technology involving more electronics, higher refrigerant pressures, higher voltages and more complexity. A conventional air conditioning unit runs pretty much like a refrigerator. When cooling is needed, the simple AC current compressor runs until the room is cool and then shuts off, recycling as needed to cool the room. It’s not unusual for conventional units to run a decade or more with only routine cleaning. Alternating current is what you get from your wall outlets.
Inverter air conditioners use compressors running on DC current. The DC compressors don’t cycle on and off, they are able to just slow down as the room is cool and speed up if more cooling is needed. Conventional compressors use extra electricity when cycling on and off, inverter units don’t. An oversize conventional unit is the worst choice, as it has to cycle off and on frequently. An undersized conventional unit can run more continuously and can actually be more efficient than an inverter unit. The inverter units use extra electricity to convert the power supply from AC to DC.
The money saving scenarios presented in the inverter brochures should not be taken at face value. One brochure in front of us claims 50% savings for the inverter unit. It compares a conventional 1.5HP unit to a 1.5HP inverter. It assumes a room area of 16.5 meters. This is the first problem. We feel a 1.5HP conventional unit is too large for a 16.6 sq meter room. A 1HP conventional unit would run much more efficiently than a 1.5HP conventional unit and possibly as efficiently the bigger inverter unit.
But the dirty secret about with inverter units in the Philippines and other tropical places is increased repair costs and reduced longevity. Conventional air conditioners often run for decades. Our 1.5HP Samsung inverter is just shy of five years old. So far it has blown out two main circuit boards because lizards crept into the high power main circuit board in the outdoor unit. This incinerated the poor lizard and the circuit board. Each board cost P7,000 ($155) to replace. In other cases ants and mice have blown boards. If you live near the ocean, salt air can corrode the boards. This is a wide spread problem that you are not going to learn about from the salesmen, but ask the service personnel, and you’ll get the real story.
Conventional air conditioners do not have these high power, lizard electrocuting, self-destructing boards. We had a visit from a friend from Australia. They have exactly the same problems with geckos shorting out inverter units. We have also read similar reports from Thailand. The Australian friend concluded that inverter units are just not suitable for use there. We have come to feel the same way regarding rural or suburban areas in the Philippines. Non-inverter units are no longer sold in Australia due to government regulations intended to save electricity. It’s our understanding that governments and utility companies like inverter units because their power consumption is more even, whereas conventional units impose significant loads when the compressor cycles on. Any electric motor uses much more current to start up than it does when it is running. That’s why an undersized conventional unit uses less electricity. It mostly is running rather than cycling on and off. Conventional units are still sold in the Philippines.
In the meantime the conventional Samsung 1HP unit we installed in our guest bedroom purrs along with no repairs at all. The Samsung Inverter cost P11,000 more than the conventional unit, repairs to the inverter unit (so far) P14,000.
So, in our view you pay considerably more for the inverter when you buy it, it might or might not use less electricity but these savings are offset by high repair costs.
Manufacturers are aware of these circuit board problems. We have read that Panasonic and Mitsubishi Heavy Industries are silicone coating their exterior circuit boards. Maybe this will help. Time will tell.
Now if you live in a place with no lizards, mice and ants, maybe the 20th floor of a Makati condo, an inverter might be the best choice. In fact inverters may be a good choice in many urban locations. If expensive repairs are not needed, they can save money. If you live in a suburban or rural area with some greenery, think twice before choosing an inverter unit. You heard it here. You’ll never hear it from a salesperson.
Here is the perspective of one recycler of air conditioning units on inverter air conditioners. Video about inverter air conditioners There is also many accounts and opinions on the Whirlpool Forums forum. Spending some time in these forums will give you a sense of the problems ordinary users have with their air conditioning units.
While the salesmen and manufacturers promote inverter units and fail to tell the customer about the problems, don’t bother to ask them to repair the units under warranty after the first year. Your gecko problem is your gecko problem and you pay for repairs. In other words, you were a fool to buy such a unit in an area populated by geckos. That is basically what Samsung has told us.
In the end we were forced to remove our Samsung inverter with a Daikin conventional unit. This is a steep financial loss, but it was a chance to test a theory of mine. After thought and research, I hypothesized that a top quality “undersized” conventional unit is the best choice for us. The Daikin 1 HP FTJ10JXVL9 we installed is rated at 9,500 kJ/h, about 2,000 kJ/h less that the Samsung we removed. Our bedroom is about 25 square meters. It definitely will not meet the standard promoted my the manufacturers who want you to install an expensive 1.5 or 2.0 HP inverter unit for this size room based on 35C outside temperature. The Daikin was installed on a hot day and definitely ran continuously and cooled the room to an acceptable temperature. Running continuously is highly efficient (the compressor is never cycling on and off) and does a good job of dehumidification. Our actual use is air con when we sleep. When we go to bed, both the inside and outside air temperatures are well lower than those proposed by the air con manufacturers. Therefore the 1 HP Daikin will be more than adequate. The Daikin has a rated cooling efficiency of 10.70 kJ/h.W, nearly as good as the inverter unit it is replacing.
So this is how we are saving money. Our Daikin cost about P25,000 installed. A 1.5 or 2HP inverter from one of the major brands would have cost at least P15,000 more, installed. The Daikin will run for years or maybe decades without significant repairs because of its mechanical and electrical simplicity. Our Samsung required nearly P6,000 in repairs per year.
We are very disappointed with Samsung, for selling us a unit unsuited to our gecko-infested rural area and then being unwilling to make repairs except at our full expense.
We bought two Samsung split air conditioners in 2011. The Samsung Inverter has been nothing but trouble, but to be fair the 1HP non-inverter Samsung split we bought at the same time has been excellent. It is made in China. The outdoor unit is of sturdy plastic, not susceptible to rusting as the steel casings are. The condenser fins have resisted corrosion better than the inverter unit even though the conventional unit is more exposed to salt air than is the inverter. It’s a well-built trouble free unit.
Daikin is a Japanese company with an excellent reputation, but its air conditioners are made in various countries. Our Daikin was made in Malaysia. We also feel Panasonic makes quality air conditioners but in the one horsepower conventional category the Daikin offered 500 kJ/h more cooling and more cooling per Watt.