Hot sultry summers and high electricity bills due to air conditioners are synonymous to each other. Air Conditioners are no longer a luxury in our twin cities. It is a necessity today, courtesy - global warming. It is one of the biggest consumers of electricity in homes and offices. The in thing in room air conditioners’ efficiency now is Inverter ACs which promise to save around 20-30% on running costs than similar 5 star rated(by Bureau of Energy Efficiency-BEE) ones too.
In traditional air conditioners, the compressor operates on cycles of on (maximum capacity) and off. In inverter driven ones, the compressor motor’s speed is varied according to the cooling demand using a variable frequency drive. This eliminates on-off cycles and hence increases efficiency and life of components. Uniform temperature is maintained as the compressor operates continuously on lower speeds as per demand. This results in a more comfortable evenly cooled room as there is no sharp rise and fall in temperatures like traditional air conditioners. Sharp fluctuations in the electrical grid are also prevented. Outdoor units are also quieter in comparison. Another advantage is that inverter ACs can operate at over capacity, that is a 1.5 ton AC can run at 1.75 ton when required. Typically they operate at higher capacity in the beginning to achieve cooling faster and then the speed is reduced to fractions of the rated capacity when the required temperature is reached.
How
it works
In the variable frequency drive, first the alternating current is rectified to Direct Current which is then pulse-width modulated in an inverter to produce alternating current of required frequency. This drives an induction motor or a brushless motor, and the speed of compressors is varied proportionally to the frequency of the alternating current.
A DC inverter Air conditioner usually costs more than normal
ones. The savings in running and maintenance bring the payback period of the
initial extra cost to less than two years depending on usage. The technology is
robust too – all air conditioners in Japan are inverter driven being a
testament to it. Next time you go shopping for ACs, look for 5 stars and ‘variable
speed compressor’ ticked on the BEE labels. You will save electricity and hence
the environment too.
