Inverter or Non-Inverter Confusion!

[prakash14]

@hotshot05 - Yes I agree that there is an electric short fall and whatever little is saved others in the grid can benefit from it. But that is only if each and every household were to convert to inverter ACs. And from what I have discussed earlier, it will save money only if you are running the AC say over 4-5 hours at a stretch. If you run the AC say 2 hours in the afternoon and 3-4 hours at night, I am not sure inverter AC will make any difference to your bills.

For invert ACs the only advantage I see is that it can run at various levels. In my sharp I have 3 options > Full 1.5 > Level L1 at 1 and Level L2 at .8. So if I set the AC at L2 then it will work like a half ton AC.

Inverter will work best only if say the sizing of AC is not correct. Say if the room is small and you install a 2 ton AC it will start stop regularly but if room is large there is no start stop. Non inverter consumes more electricity only when start > stop > start occurs. If that never occurs I doubt if inverter AC can help saving $$$.

 

[hotshot05]

Umm...you did not get my point at all.

What I meant by my post is that instead of thinking about your cost savings and return on investment, think about the greater good. You are still thinking about your cost savings only.

P.S - Usually inverters of lower tonnage can cool a bigger room effectively. If a room requires a 1.5T non-inverter, a 1.25T or 1.1T inverter can cool it effectively. So instead of comparing similar tonnage inverter and non-inverters, maybe you need to change the comparison model.

 

[cranky]

If you urinate in a river, would it be more polluted, less polluted, or just about the same? Since we are talking hypothetically.

The impact of individual savings from the grid do not impact power availability to poorer/weaker sections or areas. Just to take the example of the same state, the problem is not capacity but distribution. Over 50% of rural Bengal has no electricity connections because the grid has not even reached them.

A bigger issue is waste heat, and the generation itself. Most urban centers usually buy power from remote suppliers. I.e the Calcutta grid does not get all its power from the WBSEB, but it buys power from other power corporations as well. And since most of India still uses thermal power - the power generation is heating the environment. Couple that to the fact that power is a totally perishable commodity. If you don't use it now, it is wasted. The idea is noble, but the reality does not support the assumption. Any large scale changes in power consumption takes years to reach effect.

If you look at how the electricity companies incentivised CFLs about ten years ago - the benefits of that change are just about taking effect. Star ratings were introduced with the same idea - to balance increase in distribution consumption with lowering of individual consumption. A bit like trying to desilt a river.

 

[prakash14]

@hotshot05 - I am not sure if the individual savings can do any good to anyone. If you look it the other way most inverter ACs are imported. So by purchasing an inverter AC from a foreign brand you are adding more pressure on foreign exchange. If we purchase the same AC manufactured in India we could save that much foreign exchange! So someones gain is someones loss. Further we all think inverter AC saves power. Is anyone really sure? And if it does, how much does it save? Further how many hours before it actually saves power say if you use inverter for 1 hour and non inverter for 1 hour from start I think both would consume same power. There is a sweet point after which inverter benefits might kick in, so anyone else who could shed some light on this?

 

[rdst_1]

Damn. Should have bought an Inverter 2 years ago when I bought my Samsung 3 Star. It runs for around 20 hrs a day for nearly 4-5 months. The other AC in the house also runs close to 16 hrs and is due for a change. Will definitely get an Inverter for that room. Both rooms face direct sunlight on walls and roof throughout the day. Will it be a good idea to sell off my 2 year Samsung and get a new Inverter. May get a good deal if I buy 2 ACs together. We are really screwed in the summer months due to the electricity bills. Easily cross 6k a month during those days.

So what do you think guys. Should I replace both my ACs with Inverter units. Any idea how much I can get for 2 yr old 3 Star Samsung 1.5T Split. Also will it be better if I go this way to get a single outdoor 2T inverter and 2 indoor units.

 

[prakash14]

So what do you think guys. Should I replace both my ACs with Inverter units. Any idea how much I can get for 2 yr old 3 Star Samsung 1.5T Split. Also will it be better if I go this way to get a single outdoor 2T inverter and 2 indoor units.

If you use continuously at a stretch definitely you would save money on an inverter AC. You might get around 7k for the old 3Star AC. The cost of a single unit split in to two is quite high. Its better to purchase 2 separate with separate outdoor units. Also if you can tell us your room size L X H X B then it will help calculate volume and suggest options.

 

[rdst_1]

If you use continuously at a stretch definitely you would save money on an inverter AC. You might get around 7k for the old 3Star AC. The cost of a single unit split in to two is quite high. Its better to purchase 2 separate with separate outdoor units. Also if you can tell us your room size L X H X B then it will help calculate volume and suggest options.

Are you sure I would get just 7k for a 2 year old 3 Star Split.
I will get back to you with the room dimensions shortly.
The AC in one room runs for 20hrs for 6-7 months and the other one runs for 14 hours at least. Since for most part of the day both ACs run simultaneously wouldn't it be better for me to get a single outdoor 2T unit which once the rooms cool down is capable of idling at 1-1.2T.

If we take MHI as an example 2 1.1T would cost me 83k while 1 2T with addition indoor unit should also cost around 76k considering IDU is for 6-7k. Not much of a saving but it will definitely consume less electricity than 2 Inverter units as I am guessing it will idle to 1-1.2T when both the rooms have been cooled.

 

[prakash14]

@rdst_1 yes most likely around 7k. I think if deal done internally then you may get up to say 10-11k but I doubt if you could get more. Not sure of resale rates though.

Regarding 2 separate v/s 1 combined I think will depend on how both rooms are placed. If say the distance is more then I think the heat loss will be much more than savings because in split they usually mention around 10-15 ft distance between the AC and the outdoor unit. If its much more than that then proper insulation needs to be done. Earlier 2 splits used to cost cheaper than 1 unit but I think prices have reduced now or 2 T are not selling so higher discounts.

 

[rdst_1]

Rooms are 13x10x8 ft. Both rooms are adjacent to each other and the outdoor unit can be kept on the roof with both IDUs placed at same distance from the ODU.

 

[hotshot05]

@hotshot05 - I am not sure if the individual savings can do any good to anyone. If you look it the other way most inverter ACs are imported. So by purchasing an inverter AC from a foreign brand you are adding more pressure on foreign exchange. If we purchase the same AC manufactured in India we could save that much foreign exchange! So someones gain is someones loss. Further we all think inverter AC saves power. Is anyone really sure? And if it does, how much does it save? Further how many hours before it actually saves power say if you use inverter for 1 hour and non inverter for 1 hour from start I think both would consume same power. There is a sweet point after which inverter benefits might kick in, so anyone else who could shed some light on this?

All 2014 model Sharp inverters are manufactured in Pune. Just see the label on the bottom of the IDU.
Even though it says manufactured in India, I doubt how much of it is manufactured here. Most probably most of the components come from abroad and those are just put together in the Pune plant. They save on the tax applicable to completely built units.

Going by your logic, you should not use any laptop/PC as the processor/motherboard is manufactured abroad.

And if most of the companies started production in India, many of us would refrain from buying those and go fore something foreign made. It is just how we are. Most of us don't appreciate the quality of Made In India products. (Just see how much love Voltas/Onida/Whirlpool/Blue Star get in the AC segment compared to Hitachi/Panasonic)


Anecdote: The charger which comes with the Moto G has a label which says Manufactured in India. Many of us have a doubt regarding the quality of the charger. If the charger stated "made in thailand/china", we would not have had that much of a doubt.

 

[prakash14]

Rooms are 13x10x8 ft. Both rooms are adjacent to each other and the outdoor unit can be kept on the roof with both IDUs placed at same distance from the ODU.

Ok I think in that case you can consider the single unit split in to 2 indoor units. I think it would work out cheaper because as you say the 2 T is cheaper than purchasing 2 1 T which was not the case earlier.[DOUBLEPOST=1398048403][/DOUBLEPOST]@hotshot05 Yes agree with your logic about computers
Yes Sharp was to start manufacturing in India because the current one I have says manufactured in Thailand. I agree that it might be that they are getting all parts and say just assembling and maybe manufacturing the outer cover in India. Lets see how my AC purchase goes and will let you know. Planning to buy a 1.5 or 2T AC with or without inverter so checking what best is available.

 

[prakash14]

Ok I visited a couple of stores locally to understand their take between which is better inverter or non inverter. Mostly sellers these days simply say inverter is better than non inverter. But one shop keeper asked me for more details of my usage pattern. I mentioned that it will be used say 2-3 hours a day and he said better buy non inverter 5 Star AC as power consumption will be same as with inverter. Here was his logic. The room takes a while to cool. So first hour consumption is almost same for both. From the second hour or so the actual benefits might kick in. He says that the consumption would drop to around 900 w from the second hour for inverter. As for the non inverter as it start stops we assume it uses the full 1.4 (hence they claim a savings of around 30%). So if I were to use inverter AC for 3 hours a day consumption would be around 3-3.5 units and for non invert it would be around 3.5-4.2. Hence around .5 -.8 units savings per day. If we consider 1 unit savings and say 100 day usage its saving 100 units or max 200 units. But if you are using the AC for say 10 hours a day the savings would be much more as you can set the inverter at a lower Ton after initial cooling. This would result in savings of anywhere from 10%-40% depending on what kind of settings / environment you have.

Has anyone tried the new Carrier Midea air conditioners? They seem to have quite good features and are reasonably priced.

 

[blr_p]

So what do you think guys. Should I replace both my ACs with Inverter units. Any idea how much I can get for 2 yr old 3 Star Samsung 1.5T Split. Also will it be better if I go this way to get a single outdoor 2T inverter and 2 indoor units.

Are there any local inverters. Foreign costs more than local and you will never make up the savings because of the premium. Just ensure you have good a.s.s.

If you go foreign then its for features, reliability etc not savings. And here we enter an interesting conundrum, if you use an ac as long as you do it better be reliable but to be reliable you have to pay a premium which eats into your power savings

Is an inverter more reliable than a non-inverter. How much will repairs figure in by end of life for both. Not much use if its not working, when its hot you want something that works, you don't care about savings.

The inverter equation works out better if its one unit feeding more separate units. This was the usp to replace with inverters but the vendors got smart and decided to make a one unit inverter and then throw in some heavy marketing to push people to pay more. To get the savings the thing needs to run less so you oversize and pay more. Why not do the same with a non-inverter for less. Since you live in the interior you don't need as much moisture to be extracted as those on the coasts. Where the inverter has an advantage is if your heat load varies by how much ? 30-50% and does so on a regular basis. Here the inverter will be able to run at lower power than a non-inverter. How often will you get a heat load that varies this much. It will happen in places where lots of people move around. One minute many in the room next minute nobody in the room. One unit feeding more rooms with regular heat load changes in them is where the inverter savings really come out.

How applicable is this degree of heat load variation in the home environment ?

I'm not convinced by inverters, generally speaking a local 5 star seems the better long term buy.

 

[rdst_1]

I agree and the only reason I am gonna go for an inverter unit is if I replace both my ACs with a single outdoor unit.

 

[blr_p]

This..

Both rooms face direct sunlight on walls and roof throughout the day.

How much heat load variation is that for the rooms ?

I don't think even one inverter for both rooms will make much difference vs a 5 star non-inverter.

 

[cranky]

I'm guessing that there's a lot of guessing going on. Since this is 'Tech'enclave, we need to put some math to it.

In physics, there is a concept called the black box. Look it up. Let's take a black box and put 48000BTU of heat in it. In reality a static load is not what we encounter, but for the math it will do just fine.

Add your choices of airconditioners and work out the amount of electricity you will consume to remove that heat. It's really that simple, and the most accurate assumption you will ever make on energy cost for a given heat load.

For example, Look at the Hitachi catalog on the website, for an apples to apples comparison. You should perform this task between all the ACs you choose.

The Hitachi Ace (inverter) 1.5 Ton will remove that amount of heat in 2.5 hours, requiring 3.72kWH to perform this task. MRP is 54600.

A Hitachi Kaze (non-inverter, 2-star) 2.0 ton will do the same task in 2.1 hours, requiring 4.54kWH to perform the exact task. MRP is 44300.

For these two models the cost differential is 23% premium, the energy differential is 22% saving. Pretty much even keel so far given the same length of ownership. However compressor capacity drops over time so in a 10 year period the larger unit will last longer, OTOH the more efficient unit can start earning its keep after a while. How much depends on the exact heat load.

You can work out the TCO over a 10 year period using these units of information, and derate capacity by 5% each year (the real number is close to 10% for the first few years - and inverters are not immune). Yes there may be other factors and issues that may lead to other choices, but unless you crunch the numbers, you will never know for yourself.

(edited for calculation errors)

 

[rdst_1]

I'm guessing that there's a lot of guessing going on. Since this is 'Tech'enclave, we need to put some math to it.

In physics, there is a concept called the black box. Look it up. Let's take a black box and put 48000BTU of heat in it. In reality a static load is not what we encounter, but for the math it will do just fine.

Add your choices of airconditioners and work out the amount of electricity you will consume to remove that heat. It's really that simple, and the most accurate assumption you will ever make on energy cost for a given heat load.

For example, Look at the Hitachi catalog on the website, for an apples to apples comparison. You should perform this task between all the ACs you choose.

The Hitachi Ace (inverter) 1.5 Ton will remove that amount of heat in 2.5 hours, requiring 4.86kWH to perform this task. MRP is 54600.

A Hitachi Kaze (non-inverter, 2-star) 2.0 ton will do the same task in 2.1 hours, requiring 4.54kWH to perform the exact task. MRP is 44300.

So you have more inefficient, lower rated, lower cost AC that consumes less power at an overall level to cool the room, and yet inverters are supposed to save money. I don't see that as true in this case at least. That's marketing and how it creates 'facts'. This was the exact conclusion I reached a few years ago when looking at the new-fangled '5-star' ACs and concluded that it was all bullshit. Looks like inverters haven't changed anything at all.

You can work out the TCO over a 10 year period using these units of information, and derate capacity by 5% each year (the real number is close to 10% for the first few years - and inverters are not immune). Yes there may be other factors and issues that may lead to other choices, but unless you crunch the numbers, you will never know for yourself.

The calculations might paint a different picture but supposedly the inverter technology comes into play once the temperature has been reached.
Yes it can be all gimmicks and not much real world advantage might be there but we can't just ignore what is being touted as the USP of this technology and that is that it turns out to be more economical when ACs are run for a long period by running the compressor at a lower capacity which is just enough to maintain the temperature of the room when the excess heat has been dumped out.

However thanks for bringing the point that these decision can easily be made by doing the calculations which I am gonna start looking into now.

 

[cranky]

You can rationalise all you want. The fact is that heat is heat. Whichever way you choose to remove it. The only thing that inverters have over 'regular' ACs is the comfort factor because of a more consistent temperature. Also remember that the post compares a 1.5T to a 2.0T and is a completely random selection of models. This is assuming that the load is right-sized at 1.5T and oversized at 2.0T. If a 1.5T is undersized, the picture changes because you have an inefficient compressor trying to cope with a large heatload.

 

[6pack]

I was looking at Voltas inverter AC and found this in one of their links. I think it was the Before buying AC link in left hand side.

What is the most efficient way to use my Air Conditioner?
Ans )
ACs temperature should be set at 25 to 28 degree C. Every degree below 25 will increase power consumption by about 5% and thus cost.
Rooms should be properly insulated
The ODU/ Condensing unit should be placed at shaded place and not exposed to sun. This will save up to 10% energy
Clean filters of your ACs regularly and this can save up to 10% cost.
The optimum efficiency and EER will be at 27 degree C set temperature
Source - Center for Science and Environment ( CSE).

Also on the inverter page
www.voltasac.com/index.php?option=com_catalog&view=product&Itemid=68&id=137&cid=7&vr=302

I found this

These savings are based on 8Hrs of AC running for 365 Days
The Compressor run hour is considered as 70% of the total hours which effectively means the AC runs for 5Hrs 36Minutes per Day
Based on Electricity cost of Rs. 5/- per Unit.

So does it mean inverter saves power only at >5hrs compressor usage per day?

 

[prakash14]

@6pack - yes it might be based on what I found out yesterday and as per the shopkeeper too if you are running the AC for say 1-3 hours a day no major savings can be noticed. Also I think that the AC needs to be sized right. Say if your room needs a 2T AC and you put a 1.5 T AC then irrespective of whether its an inverter or non inverter the consumption will be more or less same. From what I have understood till now based on various interactions with sellers is that if there is start / stop more often in regular AC the savings in inverter are noticeable. But if there is little start / stop and the AC runs on most of the time, the savings are hardly noticeable. I think only if you are the "green" kind and wish to contribute your bit to the environment, will you seriously consider inverter or depending on the usage pattern, say if its 8 hours a day and for say 200 days a year.