Ask Allan: Conventional vs. Inverter A/C Units
Allan explains the pros and cons of the current air-conditioning options
Hi Allan, I have three mini-split air-conditioners that are 10 years old and may need to be replaced. I have been hearing a lot about the new inverter air-conditioners. I would like to know if you have any information that would be helpful in making my decision to go with an inverter or not. What do they cost, and will it save me some expense on my electric bill? Thanks, Alex
Hi Alex, thanks for your question.
The inverter technology is the latest evolution of technology connected to the electro motors of the compressors. An inverter is used to control the speed of the compressor motor, so it can continuously regulate the temperature. A micro-controller will sample the ambient air (room) temperature, and adjust the speed of the compressor.
Compared to conventional air-conditioners, inverter air-conditioning units have increased efficiency, extended life of their parts, and the sharp fluctuations in room temperature are eliminated. An inverter unit, therefore, would be much quieter, with lower operating costs and fewer breakdowns. The inverter units might be more expensive to purchase than the conventional A/C units, but this will be balanced out by lower electricity bills. The payback time will be less than two years, especially in areas where the energy costs are high.
In layman’s terms, I understand this to mean that with a conventional A/C unit, if you set the temperature to 72 degrees, it will sense the room temperature. When it gets to 74 degrees it turns on the compressor until the room reaches 70 degrees. It turns off the compressor when the temperature reaches 74 degrees again before turning it back on. With the new inverter units, if you set the thermostat to 72 degrees, the micro-controller will set the compressor to this temperature and it will run continuously at 72 degrees. It won’t turn the compressor on and off to maintain the desired room temp. It is the constant turning on and off of the compressor that causes noise, and use of parts and electricity.
I hope I have answered your question. I do have a few friends who have bought the new inverter units and are very happy with them. If you keep turning the inverter units on and off, you will probably defeat its purpose. FYI, my next A/C unit will be an inverter unit.
Thanks again for your question and your interest in my column. Allan