What is an Inverter AC?

While most of us are conversant with the term ‘inverter AC’, what is exactly it is? First of all, why the word ‘inverter’?

In electrical terminology, there are two types of current, first is alternating current and the other one is direct current. The process of converting alternating current to direct and vice versa is known as inversion. Usually, all our domestic appliances work on alternating current. While all electronic gadgets work on direct current.

In an inverter AC, the alternating current which comes out of our domestic power supply is converted to direct current and then further utilised thus the name, ‘inverter AC’.

All ACs consist of a refrigerant (called as gas) which is fed to indoor unit of AC in liquid form. Here, the liquid vaporizes and cools off the air which comes in contact with it in indoor unit.

These vapors then are sucked by a compressor, compressed, cooled and again converted to liquid and fed back to indoor unit and the cycle continues. A compressor is the heart of any AC and also a consumer of about 85-90% of the power consumed by AC. As long as the compressor runs, the cooling action is achieved.

A normal AC works on an on/off mechanism. It means when we give a set point of say 25⁰C, a compressor runs till the room temperature fall below 25⁰C.

As soon as the temperature falls below the set point, the compressor stops and starts back only when, the temperature of the room reaches above 26⁰C. This way the temperature of room swings between 24 to 26⁰C.

The compressor runs at its full capacity and speed when it is in ‘on’ state, consuming peak power. Due to intermittent operation of compressor, every time a compressor starts, the AC has to compress the refrigerant again back to peak pressure which is very energy consuming process followed by refrigerant circulation.

An Inverter AC works on variable compressor speed. This means that when we first start AC, its compressor will work with full speed which in turn, cools down the room way faster.

As the room temperature reaches near the set point, the compressor starts to slow down and finally runs with a bare minimum speed such that, it just maintains the room temperature precisely to the set point. The pressure of refrigerant remains constant all the times thereby eliminating that peak power surge factor in normal AC. This also makes inverter AC very quite in operation.

The alternating source of current coming out of domestic power supply is converted to direct current (DC) and then fed to compressor motor at variable voltage which operates it variable speed. Due to this conversion of alternating current to direct current, it is called as inverter AC.

Due to such smart utilization of electrical energy to work, these ACs are very energy efficient. While normal 1.5 ton AC with  5 star BEE rating will consume around 1150 watts of power, an inverter AC shall consume around 815 watts which is about 26% less. However, Inverter ACs come at cost approximately 20% higher than normal AC. So, one has to find the right balance between the one-time cost and the regular operational costs.