The Inverter Compressor was first developed by Toshiba, Japan for commercial use with cooling appliances like an air conditioner. While the general types of compressors consume high electricity, the inverter compressors utilize electricity in an optimized way.
Ordinary compressors always operate at the same speed, whereas, inverter compressors change speed when the demand fluctuates. It regulates the flow of refrigerant throughout the refrigeration cycle.
Having so many advantages, there are some disadvantages to the inverter air conditioner too. Also, with the help of the comparison of inverter AC vs non-inverter AC vs dual-inverter AC, you will clearly understand inverter compressors’ typical pros and cons.
What is an inverter Air Conditioner?
An inverter conditioner is the most power-efficient AC built with the inverter technology. It can adjust cooling speed according to the requirement but does not stop. The compressor in inverter AC that controls the temperature is always on. As a result, a well-designed inverter compressor leads to no extra power consumption while maintaining the optimum temperature.
As the room size influences the power consumption, it will draw only the amount of energy that is required to keep the temperature stable. An inverter AC adjusts the temperature according to people present in the room, heat flow, and the size of the room.
How does an inverter AC work?
Inverter AC technology is a blessing for consumers. It helps to regulate temperature without changing the compressor status. An inverter air conditioner controls the speed of the compressor rotor using a variable speed drive. When it reaches the set temperature, the inverter compressor reduces the speed of the rotor but does not turn it off. After sometimes, when the temperature increases from the set value, the inverter compressor increases the speed of its rotor, allowing more cooling.
For example, if you turn on an inverter AC set a temperature of 26°C, it will start working immediately at a suitable speed set by the variable speed drive. The speed of rotation depends upon the temperature difference between the room temperature and the set temperature. When it reaches the desired temperature, the drive automatically reduces the angular speed of the compressor. Now when the temperature reaches 27°C, it will automatically increase the speed of operation. This is how an inverter air conditioner works.
Are inverter air conditioners slow in cooling?
No, the inverter AC doesn’t cool slowly. The working method makes it look like inverter AC is slow, but it is actually not. A non-inverter AC always works at the same speed no matter how high or low is the room temperature. Thus sometimes, it over cools the room, which is not required.
An inverter AC adjusts the cooling output depending upon the temperature of the room. If the temperature is on the higher side, it works faster. Similarly, if the temperature is not that high, an inverter AC will run slower. So the working speed of an inverter AC is relative to the room temperature.
Can an inverter air conditioner Help to reduce power consumption?
This is an inevitable question that strikes our mind when learning about inverter ACs. An inverter air conditioner works with the help of a cooling substance called a refrigerant. The major component of such a cooling system is the compressor. It changes the phase of the refrigerant by compressing it through a condenser, evaporator, and throttle valve.
The refrigerant gets heated at a high temperature of the room when it passes through the condenser. After that, the refrigerant is throttled to the evaporator (to the outdoor unit) releasing heat to the outside of the room. This process is called the Refrigeration Cycle.
Instead of a reciprocating compressor, an inverter air conditioner is built with the inverter compressor. It has some significant advantages over the commonly used compressors that can help the user to minimize power consumption to a large extent.
As inverter air conditioners run continuously, it may seem that they consume more power, but it does not. You can reduce the power consumption significantly while using the inverter AC.
During starting up of a compressor, it draws the most electricity. As it is turned on all the time, it does not need to power on and off repeatedly, saving you a lot of energy. Thus, inverter compressors reduce power consumption. You can get a more practical idea in the two case studies later in this article.
A 3-star inverter AC consumes 545 watts to 1450 watts of energy for a capacity ranging from 0.75 tons to 2 tons. Similarly, a 4-star inverter AC consumes 465 Watts to 1290 Watts of power for the same capacity range. On the other hand, 4-star inverter air conditioners consume the least electricity- 450 Watts to 1115 Watts. For the same range of capacities, a non-inverter AC consumes significantly more power.
Look at these inverter ACs which we have found to be the most amazing in the market.
Advantages of Inverter Air Conditioner
- Inverter air conditioners use electricity optimally. More the fluctuations in electrical load and higher the working volume of the room lead to frequent operation of the compressor at fast speed. It results in higher electricity consumption. In the case of the inverter air conditioner, the speed of the compressor varies with the working load, minimizing the electricity bill.
- An inverter compressor is more efficient than an ordinary reciprocating compressor. Thus, inverter air conditioners are more efficient.
- Because of the variable rotor speed, an inverter air conditioner does not produce much noise and vibration. It works almost silently.
- As it produces less noise and vibration, an inverter AC does not undergo lots of wear and tear. Therefore, the longevity increases.
- Inverter Air Conditioners also work great when there is a fluctuation in the load like in marriage halls, indoor events, conference room, large offices.
- Using an Inverter air conditioner may help you save the money and the extra expense can be recovered within a few months.
- It is suitable for all sizes of rooms. In a big room, it may consume a bit more electricity compared to a smaller room as electricity consumption depends on the load. Higher the room size, more will be the load.
- You can maintain an uniform and constant room temperature inside the room if you use an inverter air conditioner. It increases the comfortability of the user.
- If you plan to use solar power for cooling, inverter air conditioners are the most popular choice.
- It can cool down the room at a much higher rate than non-inverter air conditioners.
- In Inverter air conditioners, the noise and vibration are significantly reduced.
Here is a video by LG on the advantages of a twin rotary inverter compressor.
Disadvantages of Inverter Air Conditioner
- The biggest disadvantage of an inverter air conditioner is the high price. The inverter compressor is an advanced type of compressor that has a complex design, leading to higher manufacturing costs.
- Comparatively higher repair and maintenance costs than non-inverter air conditioners.
- The effectiveness of cooling may decrease if the outside temperature is too hot, near 46°C.
These disadvantages are less significant while comparing with the brilliant advantages that we have mentioned above.
Inverter vs. Non-Inverter vs. Dual Inverter AC – Comparison
|Point of Difference||Inverter AC||Non-Inverter AC||Dual-Inverter AC|
|Compressor Unit||The compressor doesn’t switch off, but regulates the frequency of power inflow.||The compressor operates at a fixed speed – on or off. After reaching the set temperature, it turns off.||A twin rotary inverter compressor is used that has 2 compression chambers to produce a phase difference of 180°.|
|Cooling Capacity||You can adjust the amount of cooling power that is required to cool a room.||Non-inverter air conditioners’ cooling capacity is low compared to inverter systems.||The cooling capacity of dual inverter air conditioners is higher than the normal inverter air conditioners.|
|Functionality||Inverter air conditioners can function at the variable range of tonnage.||Non-inverter ACs have a fixed ton-value.||Dual inverter ACs can also function with a variable cooling system.|
|Efficiency||More energy efficient.||Less energy efficient.||Dual inverter air conditioners are more energy-efficient than single inverter ACs.|
|Cost||Inverter AC costs more than non-inverter AC.||Non-inverter AC costs less than an Inverter containing one.||It is costlier than common inverter air conditioners.|
|Noise||An inverter AC functions quietly.||A non-inverter AC makes a lot of noise while functioning.||Dual inverter ACs are quieter as their rotors turn at a 180° phase with more stability.|
|Longevity||Lasts more than a non-inverter AC.||The longevity of a non-inverter AC is not as good as an inverter AC.||The longevity of dual inverters is almost the same as single inverters.|
|Power Consumption||Consumes significantly less power than non-inverter AC||Non-inverter AC consumes 10% more power than inverter-AC.||Dual inverter air conditioners are 50% more energy-efficient than normal ACs.|
|Fluctuation in Temperature||More steady temperature||Fluctuate and consume more power at low temperature||Further stable and does not fluctuate.|
|Maintenance||Less for inverter A.C. requires low maintenance. But the maintenance cost is high if you need to replace the compressor.||More for non-inverter A.C. more maintenance is required.||The least frequency of maintenance is needed. But the cost for maintenance can be high because of the high price of the components.|
Inverter, Dual-Inverter or Non-Inverter AC – Which is the best?
Here we will analyze the advantages and disadvantages of inverter air conditioners and compare them with the non-inverter and dual-inverter AC to find out which one is the best.
Which AC has the best quality compressor?
A compressor is an essential component of the refrigeration cycle of an air conditioner that compresses the refrigerant for the heat transfer process. There is a stark difference between the compressors of the inverter, non-inverter, and dual-inverter AC in an HVAC system.
In an inverter AC, the compressor functions at a variable speed using the variable-frequency drive. It increases speed when the inverter compressor operates at peak load. After reaching the set temperature, it doesn’t switch off completely, instead; it lowers the speed to sustain the temperature.
The dual-inverter AC works similarly. But because of the twin-rotary inverter compressor, it works more efficiently by lowering vibration/noise and increasing the speed of cooling to the desired temperature.
The compressor of the non-inverter AC turns off after attaining the set temperature. When the thermostat detects a higher temperature than the set value, the compressor turns on again. During this process, it consumes a lot of electricity, thus wasting a lot of power.
Winner: Dual-inverter AC
Which type of AC has a higher cooling capacity and performance?
Based on the AC model and how you will use the device, you need to determine its performance. You can easily control the inverter compressor in an AC, as it is incredibly versatile. With the help of the thermostat sensor, it will adapt to the temperature you want in your room. This flexible nature makes the inverter the air conditioner’s performance remarkable.
The cooling capacity of an air conditioner is known for the amount of heat it removes from the room. British thermal unit or BTU calculates the estimate of the cooling capacity of the AC provides. Also, check the EER, ISEER, and BEE star rating of an AC before buying. The more EER value, the better cooling it will provide. Cooling capacity for non-inverter AC is constant and cannot change. A 1.5-ton AC for inverter can work from 3 to 1.7 tons but is fixed for 1.5 tons in non-inverter AC.
But the capacity of cooling is fixed in a non-inverter air conditioner, so you might not get satisfied with the performance of this type of air conditioner. Both the inverter AC and non-dual-inverter AC offer a decent amount of cooling.
Winner: Dual-inverter AC
In terms of functionality, which AC is better?
When someone buys an air conditioner, the first question coming to your mind will be how the AC functions for an optimum cooling effect. The inverter AC changes the compressor’s speed to vary the temperature of the room as you want. On the contrary, for the AC models without the inverter, as we have mentioned earlier, the compressor cannot be controlled from the outside, and that causes it to become non-functional, hindering it from working at full capacity.
For example, a 2-ton inverter AC can perform for 0.5 tons as well as for 1.5 tons by varying the speed of the compressor rotor. The process is very similar for dual-inverter AC too. This is called the variable cooling effect. On the other hand, a 2-ton non-inverter AC works only for 2-ton requirements. It is known as a fixed cooling system.
Winner: Inverter AC
Which Air Conditioner Cost Less?
Whenever you think about buying an air conditioner, whether from an online or offline market, determine the amount of money you will spend on it. A non-inverter air conditioner comes at a less high price compared to an inverter AC. Not only is the installation cost, but the charge for spare parts is also higher in an inverter containing an air conditioner, but it all depends on your perspective.
If you are thinking about the long term, you might first be spending a lot as the price is high for an inverter air conditioner, but in the future, you will save a lot on the electricity bills. It would be best to keep that in mind while selecting an air conditioner for your home or office.
Winner: Non-Inverter AC
Inverter vs Non-Inverter AC power consumption
Before buying an AC, it is essential to know its power consumption rate. The power consumption will reflect in the electricity charges according to the consumption. Get an AC that consumes low power. The inverter AC is an excellent option to buy, as it consumes less power. A 5 star 1.5-ton Inverter AC will consume 840 W powers for 1600 hours of use. Non-inverter A.C consumes 5 to 10% more power than an inverter AC. Choose according to your consumption, on which one suits your need best. Use the AC power consumption calculator to compute directly.
Let us consider a medium-sized room with a dimension of 10ft*12ft*8ft at a temperature of 35°C for which we need to check the energy efficiency and performance of an AC.
The approximate heat present in the room is 14000 BTU.
We need to reach a temperature of 22°C at which the remaining heat will be around 9000 BTU.
During the cooling process, conductive and radiative heat transfer occurs from the walls and heat sources like any kind of appliances or device (light, fan, computer, etc.). let us consider the amount of heat transfer from these sources as 3000 BTU.
So, when you install an AC, it needs to remove this 5000 BTU heat (14000-9000), as well as 3000 BTU of energy every hour to sustain the temperature at 22°C.
Therefore, the total heat to be removed at the first instance is 8000 BTU.
Now let us consider 2 air conditioners-
- Voltas 1.5 Ton 5 Star Non-Inverter Window AC
- Sanyo 1.5 Ton 3 Star Inverter Split AC
Case Study #1 : Voltas 1.5 Ton 5 Star Non-inverter Window AC
Cooling capacity= 5000 Watts or 17050 BTU/hr
Input power= 1492 Watts or 5087 BTU/hr
As per our previous assumption, the AC has to remove 8000 BTU/hr of energy from the control volume or the room at the first instance. This is why air conditioners consume more energy in the first hour of operation.
Therefore, the run time of the AC to remove 8000 BTU of energy is=8000/5000=1.6 hours
And, power consumption for 1.6 hours=1492*1.6=2.39 kWh or units
After 1.6 hours, once the desired temperature is met, the AC will run when triggered by the thermostat sensor. As per our previous assumption, it will run to remove 3000 BTU of ambient heat that is transferred in the control volume of the air conditioner.
Thus, in every hour, it will consume=1492*(3000/5000)=0.89 kWh or units.
Assuming you need to run an AC for 6 hours, the total power consumption is=2.39+(5*0.89)=6.84 kWh or units.
Case Study #2 : Sanyo 1.5 Ton 3 Star Inverter Split AC
Cooling Capacity=7300 to 18750 BTU/hr or 2139 to 5493 Watts
Input power=520 to 2000 Watts or 1775 to 6826 Watts
As per the empirical relationship for Cooling capacity and Energy consumption,
Y=MX + C
Where, Y= variable energy consumption; C = fixed energy consumption; M = energy consumption directly related to the cooling capacity; X= Power consumption for cooling.
We have, M=(5493-2139)/(6826-1775)=0.66
The manufacturer does not always share the fixed energy consumption(C) in laboratory conditions. For a 1.5 Ton 3 Star AC, usually, it is around 500 Watts. Let us assume C=500 for the rest of the calculation.
Therefore, to remove 8000 BTU/hr or 2344 Watts of heat energy from the room, the power consumption in the first hour of operation is X=(2344-500)/0.66=2.8 kWh or units
Like the previous case study, this AC will also have to cool down 3000 BTU or 879 Watts of ambient heat per hour. Thus power consumption afterwards=(879-500)/0.66=0.57 kWh or Watts per hour.
If you run the AC 6 hours a day, then the total power consumption=2.8+(5*0.57)=5.65 kWh
|Air Conditioner||Voltas 1.5 Ton 5 Star Non-Inverter Window AC||Sanyo 1.5 Ton 3 Star Inverter Split AC|
|Initial Power Consumption||2.39 kWh||2.8 kWh|
|Hourly Power Consumption (after initial cooling)||0.89 kWh||0.57 kWh|
|Total Energy Consumption (for 6 hrs of operation)||6.84 kWh||5.65 kWh|
So, Energy Savings in 6 hours is= 1.19 kWh
From the above case studies, we can see that an Inverter air conditioner is the best option to minimize energy consumption. Due to the presence of the inverter, Sanyo 1.5 Ton 3 Star Inverter Split AC consumes exactly 21% less energy than Voltas 1.5 ton 5 Star Non-Inverter Window AC. If you want more energy savings, go for a dual-inverter compressor.
As a non-inverter AC functions best at its full capacity, it causes excessive use of energy. This waste energy can increase the amount of your electricity bill. A dual-inverter AC can further reduce energy consumption.
Check the following table to find out the comparison of inverter and non-inverter AC as per the range of power consumption varying from 450 Watts to 1650 Watts according to the BEE specifications for AC.
|450-650 Watts||5 star 0.75 Ton |
5 star 1 Ton
4 star 0.75 Ton
4 star 1 Ton
3 star 0.75 Ton
|5 star 0.75 Ton|
3 star 0.75 Ton
2 star 0.75 Ton
1 star 0.75 Ton
|651-850 Watts||5 star 1.5 Ton |
3 star 1 Ton
|5 star 1 Ton|
3 star 1 Ton
2 star 1 Ton
1 star 1 Ton
|851-1050 Watts||4 star 1.5 Ton||Nil|
|1051-1250 Watts||5 star 2 Ton|
3 star 1.5 Ton
|5 star 1.5 Ton |
3 star 1.5 Ton
2 star 1.5 Ton
1 star 1.5 Ton
|1251-1450 Watts||4 star 2 Ton |
3 star 2 Ton
|5 star 2 Ton|
|1451-1650 Watts||Nil||3 star 2 Ton |
2 star 2 Ton
1 star 2 Ton
Winner: Inverter AC
Which air conditioner has a low operational and maintenance cost?
Factors that decide the operational and maintenance cost are power consumption and service. How often do you have to clean?
When the compressor inside needs to be changed?
How much electricity does it consume per unit?
All these questions define the operational cost.
Electricity bills can take a toll on your monthly budget. So, it would be best if you went for an air conditioner that will help you to save money on your electricity bills.
In case study #1, the power consumption to run Voltas 1.5 Ton 5 Star Non-Inverter Window AC for 6 hours is 6.84 kWh. If the electricity unit rate is Rs 6, then electricity cost= Rs 41.04/day or Rs 1231/month (approx.).
Similarly, in case study #2, the power consumption to run Sanyo 1.5 Ton 3 Star Inverter Split AC for 6 hours is 5.65 kWh. Assuming the electricity unit rate to be Rs 6, power consumption=Rs 34/daily or Rs 1017/month (approx.).
Thus, electricity cost during operation is the lowest for inverter air conditioners. From the case studies, we can see that a monthly savings of Rs 214 can be done. Though the cost of inverter compressors is high, they are less prone to damage.
Winner: Inverter AC
Generation of Noise and Vibration
As mentioned earlier, an inverter air conditioner uses less power than the non-inverter air conditioners. Due to this factor, they run in slow making low noise while working. Dual-inverter air conditioners work more silently and have significantly low vibrations. The compressor rotor rotates at a phase difference of 180° allowing the dual-inverter compressor to run at a slower speed.
Another factor contributing to less noise is that inverter ACs function and adapts according to the room temperature. It will not turn on or off all of a sudden.
So, you will also not hear the loud noise of AC starting or stopping. The non-inverter air conditioners stop functioning when a predetermined temperature is achieved. This will make a lot of unnecessary noises that will annoy the people present inside that room. These sounds will become more annoying when you are working or sleeping.
Winner: Inverter AC
Inverter or Non-Inverter AC – Which has more Longevity?
While choosing an air conditioner, it is natural to think about how long the product will last. Inverters air conditioners are often considered the best investment option. This happens because of the adaptability and durability that they offer. It will last longer than its non-inverter counterparts.
So, you can rely on the inverter ACs to last for a longer period. The same thing cannot be said about the non-inverter ACs. As these ACs turn on and off several times, the system may start malfunctioning after heavy use for a prolonged time.
Winner: Inverter AC
FAQ about Inverter AC
The Inverter AC is built for lower electricity consumption than the non-inverter air conditioner. Despite a little higher maintenance cost, it is good to use for all rooms, including small bedrooms and large halls for events. However, it involves a much higher cost than normal air conditioners. So, if you want to focus on electricity savings and a higher budget, Inverter AC can be a perfect choice for you.
Yes. It is good to use at home. It has higher performance, efficient cooling capacity, faster cooling time. Though the price is in a higher range, the extra cost can be recovered within a few months due to the lower running cost.
Some reputed brands claim that inverter AC saves up to 60% of electricity compared to the commonly available AC. Electricity consumption by inverter air conditioners depends on the working load. Higher is the load, more is the cost of electricity. But it does not cost the user unnecessary consumption of electricity.
Most of the inverter air conditioners are built to perform in a wide range of voltage. Many of the inverter ACs from reputed manufacturers work in a range of 100-290V voltage so that the fluctuation of voltage does not affect the performance. Because of this, a stabilizer is not essential for inverter AC. But, you should use one for frequent voltage fluctuation and the machine does not feature “stabilizer-free operation“.