Has AC energy efficiency increased drastically in the last decade?


rdst_1

Well-Known Member
Veteran
May 10, 2009
2,523
1,119
253
32
Natural circulation is only good enough between temperatures of 30-35 degrees and then too sometimes an air cooler would be required. As soon as you enter the 40s,you start feeling the need of an AC and then it doesn't matter whether there is air circulation or not. Same goes for high humidity areas/months.
As for the above method, it would be cheaper or at least at par if one gets a false ceiling filled with insulation. It will be much better option, if feasible.
 
  • Like
Reactions: blr_p and puns

technofast

Well-Known Member
Adept
Aug 26, 2011
371
94
67
Chennai
mine is window one only. its not low voltage issue as it cant be low voltage since past 3 months daily right. it barely cools as cold as it did earlier
It might be gas leakage also but since you say it takes time to cool there might be problem with the capacitor or even the fan motor or last thing would be a dying compressor.
 
  • Like
Reactions: RakaKaKaka

technofast

Well-Known Member
Adept
Aug 26, 2011
371
94
67
Chennai
This is like building a shed on your terrace with open sides. So pillars and roof frame made of hollow pipes and sheets on top of it. I would recommend steel sheets instead of cement sheets though. Cement sheets are very heavy and have less life as compared to steel sheets and they will be a PITA to get to the top floor because of the weight.
So basically it is a covered terrace so that sun rays don't directly hit the roof of the room.

Something like this - View attachment 80503
Similar to these I've seen in villages down south they do this with coconut leaves as a temporary shelter during the summer month.
 

adventureguy

Well-Known Member
Veteran
Nov 16, 2015
1,208
554
126
Hyderabad
Leaving aside all the technical discussion and measuring which is the right way to go, the situation right now is so bad in the really hot places that it will be difficult to rely on just on star rating and efficiency. Other factors have to be considered.
To give you an e.g, I stay on top floor and the room temperature is 43 here in Noida. My new 1.5 ton Hitachi window AC ( 3 star ) is struggling. not only during day but night.
My friend who in similar situation, I told him to buy a Ogeneral window no matter what. And turns out it was the right decision as it does a much better job. Sure the investment was higher but its worth the ROI. We couldnt buy split as its rented accomodation so with everything in mind, its best to invest in best possible efficient , tonnage, brand and technology upfront. The situation is going worse heat wise and I see no other way thesedays.
My apartment is top floor so I went 1.5t even though recommended is 1.2T. I bought a voltas 1.5ton 3star inverter AC and it barely takes 10 mins to cool the whole room.
 
  • Like
Reactions: puns

blr_p

Well-Known Member
Veteran
Apr 11, 2007
6,070
1,289
301
Similar to these I've seen in villages down south they do this with coconut leaves as a temporary shelter during the summer month.
Simpler, cheaper, safer, better looking and as effective
 

jujuburi

Member
Disciple
Jul 18, 2017
33
10
11
Have you measured this with some watt meter ?
Nah. My power metre isn't a 15V unit, 5V only. It doesn't set in the AC plug. I checked directly on the installed metre by my electric company. Just kept the AC on with no other equipment for six hours and measured.
Forget what the label says. Their testing conditions and your use case can be very different. As can be the case with the guy in the video. You both could have the same AC but the power consumption values may differ for the same settings. How big the room is, did he mention how big his room is in the video ? How big is yours ? how many times doors are opened. heat sources in the room etc. Which direction room faces, top floor, below, how much sun does it get etc. How humid. How many people in the room. AC's also remove moisture, more moisture longer they work. Many variables can influence power consumption with an AC.
Nah they never say what is their room size and all that. Nor whether the room is on top floor or ground or whatever. You are right, lots of variable here.



A fridge is simpler in this regard and even here i'm finding my power consumption values higher than what the four star sticker claims based on yearly consumption.
Yes, true. I have talked with some friends and relatives with these star rated fridges and they all say that the actual consumption is more than the printed chart. So I am sure for AC it will be same. But what matters to extent the difference will be.


How much did you pay for your window unit. Compared to how much more you would have had to pay for an inverter unit back in 2011 ?
Hard to recall but something like 24-25k I paid for the Windows unit back in 2011. Now even if I opt for the Carrier model it will cost me like 35-36k, and if Daikin or Mitsubishi then north of 46-47k.

In any case, I have done a bit of research, by almost entirely reading the Bijlibachao website and discussing with one relative who works in a top tier international power company. And I have decided to go for the best possible brand I can get in budget (looking at Daikin or General or Mitshubishi), and with the maximum possible ISEER rating. Right now one Hitachi is there with 6+ rating, but not sure about other models. It's 2019. I have been told that in India AC manufacturers don't give a two cents **** about power efficiency compared to western world. So I will get the best power efficient model available in India. I find it rather despicable to pay for high electricity consumption due to old tech. And I really don't need that chilling effect from a AC either. I keep it running whole night and I don't use a sheet or anything to cover myself, I found even 27 degrees cool enough for me.
 
  • Like
Reactions: puns

blr_p

Well-Known Member
Veteran
Apr 11, 2007
6,070
1,289
301
Nah. My power metre isn't a 15V unit, 5V only. It doesn't set in the AC plug. I checked directly on the installed metre by my electric company. Just kept the AC on with no other equipment for six hours and measured.
So that's a reliable way of getting energy consumption. What surprised me is you said it consumed exactly what the label you posted said it consumed. Is this true, something like 1400 something Watts/h ? so times 6 hours is 8.4 units ? Do another test for the same duration and post what you get.

Hard to recall but something like 24-25k I paid for the Windows unit back in 2011. Now even if I opt for the Carrier model it will cost me like 35-36k, and if Daikin or Mitsubishi then north of 46-47k.
ok so my point is how long is the payback time ?

Let's say it consumes half what your present unit is consuming. How much savings is that per month for you ? how many years until those savings amount to Rs.10k and Rs.20k

Because it is only past either of those two points that your savings will accrue

In any case, I have done a bit of research, by almost entirely reading the Bijlibachao website and discussing with one relative who works in a top tier international power company. And I have decided to go for the best possible brand I can get in budget (looking at Daikin or General or Mitshubishi), and with the maximum possible ISEER rating. Right now one Hitachi is there with 6+ rating, but not sure about other models. It's 2019. I have been told that in India AC manufacturers don't give a two cents **** about power efficiency compared to western world. So I will get the best power efficient model available in India. I find it rather despicable to pay for high electricity consumption due to old tech. And I really don't need that chilling effect from a AC either. I keep it running whole night and I don't use a sheet or anything to cover myself, I found even 27 degrees cool enough for me.
See previous question(s), then we will see if it makes sense to change AC. Clearly you are not interested in any features of these new models just the possibility of saving money on power consumption.
 

adder

Well-Known Member
Veteran
Jul 8, 2007
3,391
231
153
It makes sense to go for the most efficient machine at the time of purchase. Electricity prices are only going up and glad I bought a 5 sta 1.5ton daikin with ISEER 5.2 ac back in 2017. Bescom keeps increasing the prices(another 39paisa/unit increase incl tax from next month) and even after changing all bulbs, fans etc to the most efficient ones possible the electricity bill has only increased thanks to bescom.
 

jujuburi

Member
Disciple
Jul 18, 2017
33
10
11
It makes sense to go for the most efficient machine at the time of purchase. Electricity prices are only going up and glad I bought a 5 sta 1.5ton daikin with ISEER 5.2 ac back in 2017. Bescom keeps increasing the prices(another 39paisa/unit increase incl tax from next month) and even after changing all bulbs, fans etc to the most efficient ones possible the electricity bill has only increased thanks to bescom.
Wow 5.2 back in 2017? Kindly mention the model no. sir.
And same here. I live under CESC coverage and the electric bill has only gone upwards in last 5 years. I somehow manage to maintain it under 300 units for the per unit charge to remain at 7 rupees per unit. Above 300 units its like 10 rupees per unit. Jesus.

Wish I had the solar stuffs set up in my home. In fact that's what I am planning to do anyway the moment my financial condition restores.
 

adder

Well-Known Member
Veteran
Jul 8, 2007
3,391
231
153
It was the daikin jtkm series now replaced by jtkj series.

I was looking at mitsibushi heavy srk13yvs-w6 ,1 ton, 5.9 iseer for downstair room, no one has them in stock, same for the hitachi iseer 6.2 model (very pricey compared to daikin and mitsibushi heavy)

Godrej also has iseer 6.15 model but they use r290 which is propane, considering the pathetic installation in our country, thats a potential explosion or fire.
 
Last edited:
  • Like
Reactions: jujuburi