[kalpeshc]

Is there any recommendation for a 2T split inverter AC for the living room. From initial research it seems that General and Mitsubishi are the top dogs and the second rung probably has Daikin, Blue Star and maybe even Panasonic.

Also, Mitsubishi seems to operate under two different brands, is there any recommendation around which one to go with in terms of service, part availability, etc.?

My two Panasonic split ACs for the bedroom are going strong after 5 years and that brand is also under consideration. Would appreciate some guidance from people knowledgeable about this.

[Dr Alpha]

Originally Posted by kalpeshc

Is there any recommendation for a 2T split inverter AC for the living room. From initial research it seems that General and Mitsubishi are the top dogs and the second rung probably has Daikin, Blue Star and maybe even Panasonic.

I have 4 2T 5star inverter AC from Hitachi for past 1.6 yrs. I’ve serviced it 6 months once and they are trouble free.

Went with hitachi because service centre is nearby and I’ve been informed that since it’s manufactured in India sourcing parts will be easier.

I’ll recommend you to go with a brand which has a good service network in your locality.

[ReventonLover]

Originally Posted by kalpeshc

Is there any recommendation for a 2T split inverter AC for the living room. From initial research it seems that General and Mitsubishi are the top dogs and the second rung probably has Daikin, Blue Star and maybe even Panasonic.

Also, Mitsubishi seems to operate under two different brands, is there any recommendation around which one to go with in terms of service, part availability, etc.?

My two Panasonic split ACs for the bedroom are going strong after 5 years and that brand is also under consideration. Would appreciate some guidance from people knowledgeable about this.

Mitsubishi heavy electric is the one to go with as I got the same recommendation from two different sources in two different cities. Unfortunately, they have only one official distributor listed on their website i.e. IAPL agency. They in turn have their own network spread across the country. Mitsubishi is pretty stable in terms of performance, but their USP seems to be the airthrow in the room. If you are unable to source the Mitsubhi Heavy electric models, then even the Mitsubishi Akabashi (the other one) is not a bad choice either. I am in the process of ordering the same for some expansion work at my workplace.

In case you are unable to source any Mitsubhi machines, I would personally recommend to go for Hitachi. I have dragged my 6 year old AC across three states in the last 6 years, but it still cools down the room in a jiffy. Do make a note of the installation work being done as they don't offer company installation. It will be some agency person doing it. Barring that, I haven't faced any issues with the machine barring a wiring fault, which turned out to be a baby mouse in the indoor unit I am not so confident on General machines as they are still re-building up their network in India again. It may cause some spares or service related issue.

[self_driven]

Hi, what will be the ideal AC tonnage for a 300 sq ft room?

I'm looking for a fixed speed split AC. Room size is 15 x 20 ft. Some salesmen insist on minimum 2 ton capacity while others say 1.5 ton is sufficient. I'm confused.

[neeraj0272]

Originally Posted by self_driven

Hi, what will be the ideal AC tonnage for a 300 sq ft room?

I too want to know about this. My room size is 23 x 14.
I am thinking of going for 2 fixed speed 1 ton ACs.
I think AC salesmen oversize ACs and always suggest higher tonnage. Then these ac short cycle.
Although inverter ac will be more forgiving for sizing issues but I have multiple bad experiences with inverter aircons.

[ReventonLover]

Originally Posted by self_driven

Hi, what will be the ideal AC tonnage for a 300 sq ft room?

I'm looking for a fixed speed split AC. Room size is 15 x 20 ft. Some salesmen insist on minimum 2 ton capacity while others say 1.5 ton is sufficient. I'm confused.

Originally Posted by neeraj0272

I too want to know about this. My room size is 23 x 14.
I am thinking of going for 2 fixed speed 1 ton ACs.
I think AC salesmen oversize ACs and always suggest higher tonnage. Then these ac short cycle.
Although inverter ac will be more forgiving for sizing issues but I have multiple bad experiences with inverter aircons.

Hello to you both. 1.5 ton would be sufficient for both your use cases, subject to the conditions that you don’t live on the top floor or bottom floor (any condition) or you have more than two walls facing the outside. In these three conditions, the salesmen would be right in recommending 2T ACs. Always consider 0.5 to 1 ton extra when buying for an independent house or you are living on the extremities of vertical height.

Again, I would suggest that you go the Japanese route as the machines are more reliable. Their bling factor sure may be less (all drama features may be missing) but you’ll not regret the cooling. Top brands would be Mitsubishi or Hitachi. Daikin used to be the top dog 5 years earlier, not sure why it isn’t being recommended now. Daikin is still a good choice if Mitsubishi or Hitachi are not available. TBH, I haven’t experienced the Panasonic range. If their ACs are as good as their robots, then it can be a good choice. Also, General ain’t pretty bad.

[Aroy]

Originally Posted by neeraj0272

I too want to know about this. My room size is 23 x 14.
I am thinking of going for 2 fixed speed 1 ton ACs.
I think AC salesmen oversize ACs and always suggest higher tonnage. Then these ac short cycle.
Although inverter ac will be more forgiving for sizing issues but I have multiple bad experiences with inverter aircons.

AC sizing depends on many factors :

. Room size - around 1T per 1000 cu.ft
. Heat load - top floors more, lower floors less
. Human load - 4-5 persons per ton

So, ideally a 1.5T would be enough for 180 sq.f room with upto 3 persons on the lower floors. Please note that most of the 1.5T Inverter AC's can deliver 1.8T for upto half an hour, enough to innitially cool down a hot room, there after a 1.5T is enough.

In my case my bedroom is 150 sq.f on the top floor with front and one side facing sun. A 1.5T window was bought initially, but would struggle during peak summers. Then a 1.5T Inverter took over, but that also could not cool the room fast enough (3-4 hours to bring the temperature from 40 to 26). That is because the sun would heat up the terrace and the side walls. This year we got a 2T hot and cold for winter, and till now (at 41 peak) the cooling is much better.

Another thing to note is that modern AC have a lower gap in fins to increase efficiency. That results in the fins; especially IDU; clogging up, reducing air flow hence reduced cooling. So it is imparative to clean the IDU with water at least twice a year.

[neeraj0272]

Originally Posted by Aroy

Another thing to note is that modern AC have a lower gap in fins to increase efficiency. That results in the fins; especially IDU; clogging up, reducing air flow hence reduced cooling. So it is imparative to clean the IDU with water at least twice a year.

Meaning that we may not get claimed efficiency if it is not thoroughly serviced twice a year!

I think it's a debatable point whether consumer benefits in playing this game of efficiency.
20 years back no one bothered about efficiency. Does that mean that premium brands of those years ( like General, National , Hitachi, White westinghouse etc. ) developed and manufactured inefficient ACs at that time?
Also I read that copper tubes are now thinner and grooved inside to increase heat exchange rate but this result in refrigerant leakage as now the wall thickness of copper tube is critically thin at its thinnest point.

Annual units consumption according to BEE star label for 1.5 ton is
1 star - 1230 units
2 star - 1100 units
3 star -1000 units
4 star - 900 units
5 star - 800 units

So per star approx 100 units difference for annual 1600 hours usage which translates to approx Rs 1000 annual savings per star.
One thing that I have repeatedly stressed in this thread from my past experiences regarding inverter ac is that when there is refrigerant leakage and ac is not starting up because inverter ac diagnostic system won't let the machine start then ac mechanic will say that 'sir, there is a probability of other faults like damage to the PCBs or fan motor etc besides gas leakage but we will come to know of these other faults only after we have fixed the leak.'
So we are facing a damage of at least 3000 bucks for fixing gas leak on an already corroded and weakened copper coil with probability of spending anything between 5000 to 15000 more for any more repairs. And mind you these repairs will carry a warranty of only 1 to 3 months at max.
Also inverter PCB of every model even from the same manufacturer is different and how long will that manufacturer keep stock of these PCBs to service old models? In inverter ac there is one more problem that we can not mix and match indoor and outdoor units whereas in fixed speed we can change complete indoor unit and even buy a replacement after market brand.
Now even if we go for 5 star ac and save 4000 rs per year then that will translate to 40000 over 10 years. I don't think this is justifiable amount of savings considering the high maintainace cost of inverter ACs.

[Thad E Ginathom]

Originally Posted by neeraj0272

Meaning that we may not get claimed efficiency if it is not thoroughly serviced twice a year!

Any AC must be thoroughly serviced at least twice a year.

I think it's a debatable point whether consumer benefits in playing this game of efficiency. ... ... ...
Now even if we go for 5 star ac and save 4000 rs per year then that will translate to 40000 over 10 years. I don't think this is justifiable amount of savings considering the high maintainace cost of inverter ACs.

That's not, actually, except for very high usage, the primary reason to favour an inverter AC

I am not saying that you are wrong, and your purchase is absolutely your decision, but there is more to it...

Whilst I don't deny that greater complexity tends towards more-expensive failure, we could apply this to anything in life. As we are talking on a motor forum, how about: cars with starting handles are the best, because batteries have a limited life and alternators can develop faults! We left starting handles behind in the early 1950s.

(Maybe something like turbo would be a less absurd comparison: it is something else to go wrong, but most of us prefer the experience)

It has been pointed out that, unless one goes for some local-shop made machine, all AC systems are under electronic control now, and have been for ten or twenty years. And inverter is becoming the standard, rather than the option, so we could wonder how long the spares for obsolescent non-inverter models will be available?

Leaving aside these issues, there is no doubt that, for most people, the actual performance and comfort of inverter systems is far superior, keeping a more constant temperature/humidity and much greater comfort. And this is what one is living with each and every day. Again with a car analogy: my vehicle may be a humble hatchback, but it is absolutely not the cheapest to repair/maintain, but I absolutely do not regret owning it!

Bottom line. I have both in the house, and they both work. I could say that I have been bitten by inverter technology, having been a victim of the Sharp machine. But it wasn't the technology, it was the company's fault-prone machine and terrible service that led us, in the end, to simply treat the thing as garbage.

Personally, now, I would only buy inverter. But our decade-plus Daikin, bought used because we were short of cash when the Sharp died, is wonderful. Compare to modern machines: they absolutely don't make them like that any more. Don't expect multi-decade lifetime from stuff we buy today!

[neeraj0272]

Originally Posted by Thad E Ginathom

Any AC must be thoroughly serviced at least twice a year.

High efficiency air cons have a much higher rate of clogging so relatively they will need more servicing.

Originally Posted by Thad E Ginathom

That's not, actually, except for very high usage, the primary reason to favour an inverter AC


Leaving aside these issues, there is no doubt that, for most people, the actual performance and comfort of inverter systems is far superior, keeping a more constant temperature/humidity and much greater comfort. And this is what one is living with each and every day. !

You have a very valid point and every one has to find their own balance of comfort vs costs.
But I am sure that every variable speed (inverter) machine will fail sooner than fixed speed and even a minor failure of these inverter machines is catastrophic as I described above and which has already led me to junk 2 inverter machines within 2 years, a 3rd machine within 4 years and PCB of a 4th machine which is 7 years old has been repaired twice.
Also keep in mind that it is not as simple as replacing only machines every five years. When you replace a machine, invariable you will have to get your wall or even room painted where new indoor unit replaces older indoor unit.
When you change your machine after 5 years may be new mechanic will insist on changing lineset as well due to technical reasons or maybe just because they will say that old lineset is suspect and will not last another 10 years more! Same thing goes for wall stand or voltage stabilizers.
I am just highlighting potential issues with inverter machines which a consumer should keep in mind.
As for electronics in fixed speed machine fortunately companies are not developing new models in fixed speed so they keep on manufacturing old basic models.
Personally only thing I want from an ac besides throwing cold air is timer function, air throw swing function and fan speed and thermostat function. To me everything else is a gimmick.

As for people relying on 5 years warranty of PCB, what if company says that PCB is out of stock and they have to get this particular PCB from their central warehouse on order and it will reach in 15 days. I hope these people have extra bedrooms because sure they won't be having extra air cons in a single bedroom.
It happened to me in case of plasma tv when Panasonic and Hitachi both took weeks to repair TVs.

[Gansan]

If we are going to use just one or two Ac machines that too for a few hours a day, very little power will be saved by 5 star inverter units, which will be more than offset by high maintenance/gas/parts charges and associated headache. In such cases non inverter 3 star units make sense.

A neighbor of mine installed a split Ac for his bedroom for the first time and I imparted this knowledge to him. But he ultimately installed a 5 star Votlas inverter unit. Swore that he searched everywhere for the other article but could not find it. I suspect hard sell by the Ac shop.

In my opinion if one is not going to run at least four Ac machines each at least for ten hours a day, stay away from inverter Ac. Life will be simpler and happier.

[Aroy]

The BEE figures for annual electricity consumption are based on some assumptions. These may or may not be valid in a particular case.

That said Inverter AC efficiency depends on two factors
. Thermal efficiency of the IDU
. Thermal efficiency of ODU

The thermal efficiency of a heat exchanger depends primarily on the area of the heat exchanger and the air flow. To increase efficiency the fins are spaced closer. In some case the IDU is wider, but in most cases the IDU width (hence area) remains same for 1T, 1.5T and 2T. That is why the higher tonnage AC have lower star rating in many cases.

Regarding power consumption, as I have written earlier, the Inverter consumes much less and there is no starting load. Here are some figures

1. Hitachi 1.5T window - 11A-12A running
2. LG 2T Inverter - ambient 41 degrees
. 9.6A in turbo mode
. 7.5A normal while starting
. 5.6A after the room has cooled from 32 to 27 degrees (1H)
. 2.4A after 3 hours
. 1.5A at night (32 degrees ambient)
. 0.9A during rains

So on the whole the power consumption of old Hitachi over 15h is 11Ax15x.6 (60% on) = 99 AH

For Inverter it is (9.6+7.5x2+5.6x4+2.4x8) = 66 AH

So the 2T Inverter AC consumes 2/3 the power of a 1.5T old AC

These figures are conservative in the sense that the older AC would rarely have a 60% on cycle more like 80% on hot days, while the Inverter would revert to less than 2A at night.

Also as the Inverter AC have a "soft start", that is the current ramps up slowly, the load on wiring is much less than fixed speed AC. Inverters can easily run on house hold inverters as long as the ratings are a bit higher (as there is no starting current peak).

[Prowler]

Originally Posted by Thad E Ginathom

Leaving aside these issues, there is no doubt that, for most people, the actual performance and comfort of inverter systems is far superior, keeping a more constant temperature/humidity and much greater comfort. And this is what one is living with each and every day. Again with a car analogy: my vehicle may be a humble hatchback, but it is absolutely not the cheapest to repair/maintain, but I absolutely do not regret owning it!

Compare to modern machines: they absolutely don't make them like that any more. Don't expect multi-decade lifetime from stuff we buy today!

Excellent points as always. In the initial stages inverter ACs tended to have higher failure rates but as of now they have improved the electronics so much that the manufacturers have started giving 5 year warranty on their PCB. Compressors have become so reliable in all these years that most manufacturers offer 10 year warranties. So the reliability of Inverter AC has come to the same level as the fixed speed AC.

It is almost difficult to buy a fixed speed split AC these days.

But consider the cost of operating the ACs. I will quote from my own example - A fixed speed AC consumed about 230 units whilst an Inverter AC serving a similar sized room consumed only about 120 units - a difference of 110 units. With the current utility rates prevailing in Tamil Nadu it is a saving of about Rs.1200/- per month (~ Rs.14400/- per year ignoring other factors).

[locusjag]

My furtive, unsuccessful search for a cost-effective home cooling solution
I'm from a simple middle class family background and constantly running an AC at home is still frowned upon in the family. We tend to ration our AC usage, if only to soothe our miserly minds.

On the other hand, Chennai gets to be extremely hot and humid in summer. The humidity bit forbids use of Air Coolers, which people from the dry-hot areas of India would be familiar with as a lower cost cooling solution when compared to Air Conditioners ("ACs"). One is practically solely left with ACs in Chennai for home cooling in the summer.

Or is it?

Radiant cooling for homes - sounds too good...
I happened to stumble across a particular Tamil YouTuber's video on Radiant Cooling technology.

https://www.youtube.com/watch?v=5MqzgFJ7e1A

This is essentially a method that involves embedding of pipes that snake across the floor/ceiling of homes/buildings. These pipes will need to be laid at the time of construction, or existing floors will need to be dug up and the pipes will need to be laid, after which concrete will need to be poured over it. There'd be a simple little water pump in the terrace (or basement) which will pump water from a small water tank across the building constantly. The constant circulation of water across hot and cold zones would wick away excess heat from the building's hot zones and maintain a uniform temperature in the building (around 20 to 25 degrees Celsius).

The only major costs you need to bear are the upfront installation costs. Running costs are very minimal.

...but I didn't quite put my money where my YouTube research led me
I won't adopt the Radiant Cooling solution, for the following reasons-
1) Although the positions of the snaking circulation pipes on each floor will be marked by the contractor who installs the cooling system on engineering diagrams for future reference, one can't be sure if one runs the risk of damaging the pipes later on if the floor is drilled for any reason later on. Plus, you'll need to warn contractors to use some sort of underground detector-sensors (?) to locate the pipes in order to avoid hitting them.
2) If there's a slow leak from the pipes, your floor will have had it. Reinforced concrete will surely fail with slow water leaks from the inside. If you detect it on time though, the repairs can be performed precisely wherever the leaks have sprung from, by digging up the floor concrete at the impacted site alone; you won't need to dig up the entire floor.
3) It seems that moisture collects due to condensation on chilled roof/ceiling surfaces and that eats into the concrete sometimes over a period of time.

Is there any live example of an installed, working Radiant Cooled home/building?
The YouTube video shows a building that's Radiant Cooled. It happens to be the very premises of the contractor in Chennai who implements it. I have also heard of an engineering college in Chennai where this has been successfully implemented.

Bottomline
This technology is very eco-friendly; the YouTube video shows the 1 HP water pump being powered by a small solar panel and that would cost you next to nothing. Even without a solar panel, it will cost way lesser on your wallet, when compared to running an AC (or more) over a number of years.

But it's an unknown technology in the Indian Market and I'm no early adopter with a huge risk appetite to implement this. If you are a risk-taking early adopter with the risk (and financial) appetite, go for it.

For sure, if you're running a business on premises where you're incurring huge bills on ACs and if you can offset certain recurring building repair costs as tax saving "business expenditures", this solution can help you save a tonne of money in the long run.

PS: It seems that the Indian Govt. even provides subsidies for Small/Medium businesses to implement Radiant Cooling, as it is a Green cooling solution - https://www.indiascienceandtechnolog...adiant-cooling

[sandeepmohan]

Originally Posted by locusjag

The constant circulation of water across hot and cold zones would wick away excess heat from the building's hot zones and maintain a uniform temperature in the building (around 20 to 25 degrees Celsius).

Interesting concept. I feel this is more suited for dry weather. Not for hot and humid cities like Chennai, etc.

This should get temperature down to a comfortable level. I am not sure how well it extracts humidity or moisture. Aside from cooling a specific area, the other advantage of air conditioning is humidity extraction or removal. Makes a world of a difference.

If it were easier to implement, the uptake will be higher for such a system. Its so easy to buy and fit an air conditioner these days that you'd rather not head down a complicated path of running water carrying pipes through your walls, etc