Author Options:

electrical Answered

Why does an AC of 1.5 Ton with 1 to 5 Star rating differ in power consumption though they all have the same compressor. I fail to understand how a 1 Star AC consumes more current than a 5 star rated AC?


I am not talking about the running of the AC.

Before the AC is installed and running it is rated 1 Star to 5 Star. How is that possible?

I don't think we get your question. Maybe you can link us to the a/c units you are comparing? They usually have the complete units installed in a test room/house to evaluate them. If you are saying the unit states a rating with a range of 1 to 5 stars, then the unit will perform poorly in drafty uninsulated house to well in a modern energy efficient home and the marketing people gave it to the lawyers to write up the ratings..

Or is it a sales gimmick? The cost of a 5 Star is more than a 1 Star, so why not make all 5 Star and save the world of Electrical energy.........

I still don't see what you are questioning. Think of the Star ratings like the mpg or (kilometers per liter?) estimates for a new car. You have not driven it so how can they figure out those numbers? Some cars are good, some better. The ones that get better gas mileage will cost more because they have more advanced engines and components of the car are more expensive. You try to buy the best for your situation. Someone will still buy that low end car because there is a market for it. They will still make more. They created Star ratings so you as the consumer can compare models without doing the lab work yourself. Consumer ratings are for the general public so as an engineer or scientist you would want a more detailed report.

Maybe this is of any help...
As I said earlier: Devices are tested and rated and it has nothing to do if it is installed at your place or not.
The testing is done before a new device actually is available for sale.

Nobody has got my Question yet...Same company, same Compressor, same AC but rated 1 to 5 star ...Why. Why not make all 5 star rated AC's.

Same company, same compressor...but not the same A/C unit. There are other (more numerous and expensive) components that increase the efficiency and the cost of the 5 star units.

It's not so much a "sales gimmick" as a manufacturer trying to meet two different "price points." People with a tighter budget will opt for the cheaper, less efficient unit. Does not save them money in the long run, but those are the economic realities...

May be you are right, you can't make fools of all the people all the time......Thanks

Energy rating is a thing of running costs, not the rated power of a device.
As you noticed some use the same compressor but fail to get a good rating.
This can be due to a number of facts:
cooling cycle period
size of the unit itself
rated room volume to be cooled - the "same" aircon but rated for a bigger room size will get worse ratings as it uses more energy

The list can be expanded but it is a similar story with a fridge...

I think you need to look into how your air conditioners are rated or evaluated for efficiency and energy consumption. I am guessing on a scale of 1 to 5, 5 is the best. Given that the range of models use the same compressor the other parts of the equation are how they control and sense the cooling, how much or what kind of refrigerant cooling liquid/gas is used. Radiator fan or size of the heat sinks(those metal fins on the pipes that always get dinged). Is the fan continuously running or is it electronically throttled. A lot of variables, simple thermostat or electronic control...did VW provide the software...