[Sherlocked]

Originally Posted by Aroy

LG 2T AC are all 3 star. If you can manage get their 1.5T 5 star ones, much lower power consumption. As far as cooling goes a 5 star 1.5T inverter AC will have similar or better cooling than a 15 year old 2T window unit.

The room in which the AC will be installed has two parts:
-one 12*13 feet area and another 8*8 feet area so a total of around 220 sq.feet area. Do you think a five star 1.5T AC will be sufficient for the given room size? One wall with the 70% almirah area is south facing and the roof is exposed to sun with white tiles flooring. Rest none of the wall is exposed directly to the sun.

What I can do is partition the two areas with thick curtains and install the 1.5T AC in 12*13 room which will be mostly occupied as the AC will majorly run during the night only when the 8*8 room will not be used at all.

The other option is getting a 2T AC without any partition being made.

Which one do you suggest?

[anupmathur]

Originally Posted by Sherlocked

... Do you think a five star 1.5T AC will be sufficient for the given room size? ...

I would recommend you go for a 3* AC rather than a 5*.
These 5* ACs with their very fine/small condenser fins pitch get clogged within a few days. What that does is make your AC less efficient and thereby increase the power consumption. There is no real saving with a 5*, particularly in cities that are dusty!

[Guite]

Originally Posted by anupmathur

I would recommend you go for a 3* AC rather than a 5*.
These 5* ACs with their very fine/small condenser fins pitch get clogged within a few days. What that does is make your AC less efficient and thereby increase the power consumption. There is no real saving with a 5*, particularly in cities that are dusty!

I beg to disagree. We have 5 star AC for the last 9 years, added few more in recent years. Noida is dusty, even more so than Delhi because of construction work around. Our power bill during summer is usually half of our friends living in same type of apartment, them using 3 star AC. For us the saving in recurring cost has far made up for the initial capital cost difference.

[anupmathur]

Originally Posted by Guite

I beg to disagree. .... Our power bill during summer is usually half of our friends living in same type of apartment, them using 3 star AC. ....

Oh, I see. About half, hmm. Difference between a 3* and a 5* AC. Great to learn this. Thank you.

[Behemoth]

Originally Posted by anupmathur

Oh, I see. About half, hmm. Difference between a 3* and a 5* AC. Great to learn this. Thank you.

The difference between the COP (or ISEER) for 3* and 5* AC is 3.5 vs 4.5 so the energy consumption difference should be around 25% and will not be more than this. 50% is quite unreal and may be due to other usage patterns or outside weather variations.

[anupmathur]

Originally Posted by Behemoth

The difference between the COP (or ISEER) for 3* and 5* AC is 3.5 vs 4.5 so the energy consumption difference should be around 25% and will not be more than this. 50% is quite unreal and may be due to other usage patterns or outside weather variations.

Thank you, Behemoth; I too calculated about the same. But who will tell those who think otherwise?

[Behemoth]

Originally Posted by anupmathur

Thank you, Behemoth; I too calculated about the same. But who will tell those who think otherwise?

Yup I guess there is generally a euphoria factor when people buy 5 star ACs! No pun intended (I am also one who prefers high efficiency equipment!)
But that said the difference above in consumption could be because one apartment faces North side and the other one faces South side. The solar heat gain of the South wall side is almost 40% higher.

[Aroy]

Originally Posted by Sherlocked

The room in which the AC will be installed has two parts:
-one 12*13 feet area and another 8*8 feet area so a total of around 220 sq.feet area. Do you think a five star 1.5T AC will be sufficient for the given room size? One wall with the 70% almirah area is south facing and the roof is exposed to sun with white tiles flooring. Rest none of the wall is exposed directly to the sun.

What I can do is partition the two areas with thick curtains and install the 1.5T AC in 12*13 room which will be mostly occupied as the AC will majorly run during the night only when the 8*8 room will not be used at all.

The other option is getting a 2T AC without any partition being made.

Which one do you suggest?

Install the curtain. If nothing else it will give the main room a semblance of privacy.

I think you said that you will be replacing window AC with split. That gives you at least 25% advantage in cooling. Here is my experience
. Had a window AC in our bedroom - 16' x 12' (nominal) minus walls so around 15.25 x 11.25 ~ 170 square feet. Two sides plus terrace get full sun during the day.
. Last was Hitachi 5 star window. During summers it would cool just about adequately.
. Within a month of wet cleaning, the cooling would start dropping and within three months it would barely cool at night.
. As the rear side is on sheer wall there was no method of cleaning the AC except by taking it out and washing. This was done at least two time and normally three times a year.
. Got LG 5 star split, with the ODU on the terrace. Within two days after a dust storm the AC cooling started reducing. Called the engineer who just banged the ODU and loads of dust fell out. Washed the ODU fins with a couple of mugs of water and AC was back in business.
. The service engineer advised me to wash the ODU fins at least once a week, and after each dust storm. I have been doing this and the AC works perfectly. Where the new 5 star 1.5T window used to achieve 28 degrees in two hours, the 5 star Inverter split achieves it in 15 minutes. When it was 42 degrees recently, it achieved 25 degrees (with Himalaya Cool option) in less than one hour and maintained it in normal mode. A thing that the window AC could never achieve.

In conclusion
. Split Inverter AC cools at least 25% more than a similarly rated window AC.
. In dusty NCR environment, the ODU has to be cleaned regularly; compared to coastal region; to maintain peak efficiency.
. 1.5T 5 star Inverter compared to window AC; at least in our case; reduces the power consumption from 1900W peak to 1400W peak, a clear 25% saving. At lower power level - after the room has cooled sufficiently, the absolute power consumption difference would be much less, but still there.
. What is alluring about current 5 star inverter AC is that they are normally stabiliser free (a source of reduced efficiency), and less prone to power related failures.

[sgiitk]

Originally Posted by Guite

I beg to disagree. We have 5 star AC for the last 9 years, added few more in recent years. Noida is dusty, even more so than Delhi because of construction work around. Our power bill during summer is usually half of our friends living in same type of apartment, them using 3 star AC. For us the saving in recurring cost has far made up for the initial capital cost difference.

A nine year old 5* will now be at most a 2 or 3. Ratings are changing all the time - I think once in 2-3 years max. This is technology. When looking at the ratings also check for which year!

[Sherlocked]

Originally Posted by Aroy

Install the curtain. If nothing else it will give the main room a semblance of privacy.

Mom is against those PVC/plastic curtains which I am coming across internet to have partition in AC rooms. She says they'll not look nice in a bedroom and might require frequent cleaning. Any idea if thick fabric curtains would be useful in this scenario?

I think you said that you will be replacing window AC with split. That gives you at least 25% advantage in cooling.

Even I'm insisting on a split unit only. Thanks for sharing your first hand experience and those points. They have made my decision for the split unit only. The question now remain either 1.5T (with partition) or a 2T unit without partition. AC will run maximum 8 hours a day.

[sandeepmohan]

Originally Posted by Aroy

Split Inverter AC cools at least 25% more than a similarly rated window AC.

How old is your window aircon?

I have not found any difference in cooling ability of an inverter split vs non inverter window. Splits quite obviously operate a lot quieter as the noisy mechanical bits are separated from the main unit. The former is also easier to install and then off course, aesthetics are generally better with a split. From a power saving perspective, an Inverter unit is sure to consume less power when used right.

[Lobogris]

Originally Posted by Sherlocked

Mom is against those PVC/plastic curtains which I am coming across internet to have partition in AC rooms. She says they'll not look nice in a bedroom and might require frequent cleaning. Any idea if thick fabric curtains would be useful in this scenario?

Can you share a link for these PVC/ plastic curtains? I am looking for them as well.

[Aroy]

Originally Posted by Sherlocked

Mom is against those PVC/plastic curtains which I am coming across internet to have partition in AC rooms. She says they'll not look nice in a bedroom and might require frequent cleaning. Any idea if thick fabric curtains would be useful in this scenario?
.........

I agree with your Mom. Get thick fabric curtains stitched at the shop. Here in Delhi, most shops selling upholstery material have a tailor who will stitch curtains to your size.

Before you get the curtains you will have to decide on what sort of a curtain rod you like and install it, as the curtain stitching is specific to the rod.

[Guite]

Originally Posted by Sherlocked

Mom is against those PVC/plastic curtains which I am coming across internet to have partition in AC rooms. She says they'll not look nice in a bedroom and might require frequent cleaning. Any idea if thick fabric curtains would be useful in this scenario?

In our house we have managed with a thin sheer curtain between living room and dining room. It is semi transparent not because of big gaps in the curtain but because of fine fabric and tiny gaps between the threads.



In my opinion it serves the purpose of isolating air of one space from another. Its is not air tight but air does not pass freely through the curtain unless you blow directly at it with a fan. For us it is a good compromise between aesthetic and air isolation.

[Sherlocked]

Originally Posted by Aroy

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Originally Posted by Guite

.

We dumped the idea of curtains and eventually got the LG 2TR dual inverter AC installed today. Thanks for your advices. Much appreciated.

Originally Posted by Lobogris

Can you share a link for these PVC/ plastic curtains? I am looking for them as well.

You will find plenty of them on Flipkart or Amazon with search keywords as PVC curtains.