AC buying advice

[champ_rock]

Hi

I have a General 1.5ton AC which I currently use in my room. It is a very old model (10 years old or so). I asked the service guy to service it and he said that the gas had leaked and was charging 2k for it. So, an interesting thought came to my mind .

If I can sell this inefficient power guzzling AC and buy a new one then in how many years would I be able to recover my cost?

Calculations are as follows:

Benefit from selling old ac: Rs. 5k

Saving in gas refilling: Rs. 2k

Net saving: Rs. Rs. 7k

Buy a new AC for 1.5ton for Rs. 20k to 23k.

So, the new AC cost would be Rs. 13-15K.

How much energy saving do you think happens in this strategy in order to be able to recover this Rs. 13-15K investment?

Thanks!

 

[guptavis]

Interesting idea, here is what i think:

It depends on how many hours in a day you run your AC, the cost of electricity in your region and the comparative consumption of your old AC and the one you wish to buy.

On a general idea, IF your old AC is inefficient it could be drawing around 15-16 Amps (i have seen some draw in the range of 20A) which translates to 4 units per hour.

An efficient new AC takes 7-9 Amps which is around 2 units per hour. So taking electricity cost as Rs5/unit you could save Rs10/hour.

So 13k difference would be recovered in 1300 hours of running. That is around 3-4 months if you run it 12 hours a day.

So if you plan on running you AC even 6 hours a day you would recover the cost in two summer seasons.

Also you'll have better, quicker cooling and quieter operation.

Not to mention you'll be doing the nation and the world a favour by saving electricity, so go for it!

 

[mehrotra.akash]

You need to tell the Cooling capacity (in watts), power drawn by the current AC, hours of running per year, cost of electricity per unit to get an accurate estimate

That said, comparing to an equally old Westinghouse AC I had, the savings had come out to 1 unit per hour which meant it didnt really make sense for me to change it for power savings alone

Interesting idea, here is what i think:

It depends on how many hours in a day you run your AC, the cost of electricity in your region and the comparative consumption of your old AC and the one you wish to buy.

On a general idea, IF your old AC is inefficient it could be drawing around 15-16 Amps (i have seen some draw in the range of 20A) which translates to 4 units per hour.

An efficient new AC takes 7-9 Amps which is around 2 units per hour. So taking electricity cost as Rs5/unit you could save Rs10/hour.

So 13k difference would be recovered in 1300 hours of running. That is around 3-4 months if you run it 12 hours a day.

So if you plan on running you AC even 6 hours a day you would recover the cost in two summer seasons.

Also you'll have better, quicker cooling and quieter operation.

Not to mention you'll be doing the nation and the world a favour by saving electricity, so go for it!

You wont have better cooling if the old AC is well maintained, and the savings calculations are somewhat optimistic (compressor doesnt run 100% of the time, so it favours a new AC. Also, doesnt consider the difference in cooling capacity between the old and new AC. Sometimes old AC's have a higher cooling capacity but are rated at the same tonnage. So, an old 1.6 ton and a new 1.4 ton will both be labeled 1.5 ton. To show higher power savings, the chance of an AC being overrated is higher now, so compressor will run for longer in the new one compared to the old one, further invalidating the comparison)

 

[sbhas2k]

Also a flaw in your calculation, No one can sell or buy an 10 year old AC which has problem with Gas for 5k, You can expect at max 3k or even less i guess.. Personal opinion and may be wrong..

 

[guptavis]

You wont have better cooling if the old AC is well maintained, and the savings calculations are somewhat optimistic (compressor doesnt run 100% of the time, so it favours a new AC. Also, doesnt consider the difference in cooling capacity between the old and new AC. Sometimes old AC's have a higher cooling capacity but are rated at the same tonnage. So, an old 1.6 ton and a new 1.4 ton will both be labeled 1.5 ton. To show higher power savings, the chance of an AC being overrated is higher now, so compressor will run for longer in the new one compared to the old one, further invalidating the comparison)

As stated, It was just a rough idea. And most newer ACs do have better cooling than a 10 year old one even if well maitained. Running and climatic conditions do wear out machinery especially compressor and coils.

Also a flaw in your calculation, No one can sell or buy an 10 year old AC which has problem with Gas for 5k, You can expect at max 3k or even less i guess.. Personal opinion and may be wrong..

I sold my ~20 year old 1 ton voltas for 4.5k last year (and 1k for old transformer = 5.5k total). So it depends on which city you stay i guess.