AC vs Ceiling Fan — Conflict Resolved
For a long time now, this conflict between usage of air conditioners and ceiling fans are on. From power savings to thermal comfort, these cooling appliances are at war since the invention of AC. In a country like India, where ceiling fans are the predominant cooling appliances, ACs are slowly taking up their place.
How it all started?
Ceiling fans have a long history and they are evolving from 4000 BC. The early ceiling fans were made of palm leaves and the manual ceiling fan originated in India by the name of Punkahs in the 17th century. With the development of electric motors, electric ceiling fans came into operation in the 1880s. During these years, the USA was taken up by ceiling fans.
Ceiling fans ruled for a century, and the downfall of ceiling fans in the USA began in the year of 1950 by the invention of AC. Slowly ceiling fans became extinct in the USA, but in India, it was a boon. More and more ceiling fans were manufactured in India and today over 500 million are in operation. You can read more about ceiling fan history in India here.
Evolution of ceiling fan technology was not much in the following years. A wave of revolution in the ceiling fan industry began in the year 2012 in India after introducing super energy-efficient ceiling fans. Between the years 1950 to 2012, there were so many crises like 1980s energy crisis, air pollution, ozone depletion and health issues caused by coolant usage. Many deliberations went on describing the hostility in using the AC. For nearly a century now ACs are debated in terms of comfort and air pollution.
How was it resolved?
ACs are energy predators who damage the atmosphere. A single 1.5 ton AC will consume 1676 W/H adding up to 7 k Units of electricity demand in a year. Apart from power consumption, AC’s coolants like R410A and R32 are global warming potential and ozone depletion potential.
On the other hand, better thermal comfort and quieter operation (indoors) are the influential perks in using an AC when compared to ceiling fans. We need to compromise either thermal comfort or power savings. This too much to ask for, right?
Isn’t there a solution to maintain the same thermal comfort of AC at reduced power consumption? Yes, there is. The optimised solution is by using a ceiling fan together with AC.
How using ceiling fan with AC will reduce power consumption?
Ceiling fans promote air circulation while AC maintains the room temperature. By using AC with a ceiling fan at speed step 2 or 3 will give you the thermal comfort of 27-degree setting at 24-degree setting. The three-degree comfort will be taken care of by the ceiling fan. This is the sweet spot.
This concept is proven and has been promoted by government agencies like BEE in India.
There is a misconception that the electricity consumption increases if the ceiling fans are used along with ACs as they push the sultry air down. It is far from the truth when ceiling fans are used at low speed with ACs, there is a breeze effect which can reduce electricity consumption. The breeze provides evaporative cooling on top of the temperature cooling of the AC. This double cooling allows the occupant of the room to set the AC temperature higher than the normal 24 degrees and experience the same comfort. It is revealed that each higher degree setting in the AC saves 5% electricity consumption as the AC compressor works for a lesser duration.
It is a rule of thumb to set the AC at 27 degrees and run the ceiling fan at speed 2 to enjoy the most savings for the best comfort.
This strategy would work best if the ceiling fan generates the least amount of heat during operation and consumes the least electricity. A regular ceiling fan motor heats significantly above the room temperature. The AC compressor has to work against this heat to provide comfort. But a BLDC ceiling fan like Superfan runs cool and generates less heat even after hours of operation. Hence Superfan with your AC can save thousands over a year than a regular fan with AC.
I recommend you to opt for super energy efficient ceiling fans to be operated with AC. The following section will say why.
Why Super Energy Efficient Ceiling fans?
Super energy efficient ceiling fans like Superfan, consume 56% lesser power than regular ceiling fans. This is possible with the BLDC technology that reduces the losses in commutation. Read here to know the difference between a regular ceiling fan and super energy efficient ceiling fan. Let us find the sweet spot to optimise the thermal comfort and power savings by using Superfan with AC through the following calculations:
Regular fans consume 39 W when running at speed step 3 and Superfan consumes only 14W. In an entire night, i.e. 12 hours of operation for a year:
Regular fans → 39 x 12 x 365 = 170 Units of electricity
Superfan → 14 x 12 x 365 = 61 Units of electricity
Superfan ceiling fan with AC
Besides monetary benefits, 1 kg of CO2 emission will be avoided per day per fan by choosing super energy efficient ceiling fans like Superfan.
Hurray! That’s how the conflict is resolved, optimise both your AC and ceiling fans for thermal comfort and power savings. Choose wisely for a better tomorrow.
Originally published at https://medium.com on June 15, 2020.
