[sagarpadaki]

Originally Posted by Prowler

Set it to 21 and set the fan speed to auto. Set the sleep mode also which would quietly increase the temperature settings by one degree every hour(most ac will allow you to set the temp/hour as per your convenience). If you sleep for 8 hours, it will end up at 29 degrees by the time you wake up.

21 degrees is too cold I feel, especially when the AC has removed all the humidity from the room. From a energy point of view as well, 21 is very inefficient.AC will consume a lot of electricity to bring down the room 21 degrees - unless the room is has minimal air leakage.

[Prowler]

Originally Posted by sagarpadaki

21 degrees is too cold I feel, especially when the AC has removed all the humidity from the room. From a energy point of view as well, 21 is very inefficient.AC will consume a lot of electricity to bring down the room 21 degrees - unless the room is has minimal air leakage.

I agree 21 degree C is a bit too cold. But the idea was to give sufficient headroom for the 1 degree/hour sleep mode.
As for the energy efficiency, the thermostat sits on the intake side and decides it has cooled the room to the set temperature even if the far corner of the room is hot. As a result, the compressor winds down after some time as if the entire room is cooled. We can see this in our office hall - where the AC is at one end and when set to 18 degree C, it winds down to maintenance mode of around 600 VA after about 30 min.

[IamNikhil]

I have a Panasonic Inverter Split AC 1.5 ton in our bedroom. We set it to 24 Degrees and Fan on auto mode. The room gets chilled in no time. More often than not, we increase the temp to 25 Degrees. Our practice is letting the AC make the temp comfortable to sleep and then switch it off after around 3 hrs and switch on the ceiling fan for the rest of the night. Works wonders and sleep is never disturbed.

[Gansan]

I don't understand what is going to be achieved by setting the AC at 20 degrees instead of 24 degrees. In the current climate it is not going to matter. For the initial couple or three hours both will make no difference because the compressor will be running whether the set temperature is 20 or 24. The difference will come only after the room has cooled to 24 degrees.

Whatever temperature we set, the air that comes out of the AC will be at 18 or 16 degrees, according to the lowest temperature of the particular Ac. It can't be varied even if we set the Ac at 26 degrees. It is just that the thermostat will cut off once the desired temperature is reached. 24-26 is achievable in a few hours given the current climate. I don't think 20 or 21 will be achieved even if the compressor runs throughout the night. So it will never cut off.

[harry10]

This is where I am enjoying our new Panasonic wifi AC.
It's default sleep profile works perfectly at night. At times I use my own custom profile too with 1 degree less than default profile.

Also the power consumption graph is doing justice to this sleep profile. Attaching screenshots for both.

AC is on cool mode and Fan speed is at Auto for the same.

[sirius]

The outside temperature is 41 degrees and I kept my AC at 28 and ceiling fan at 4 (out of 5) speed and feeling quite comfortable. Also, it is the topmost floor (actually the only floor). Location: near Hyderabad. I think people in coastal regions are at a disadvantage in this regard.

[Gansan]

^^ Not really. I keep the Ac at 27-28 when the temperature outside is at high 30s or 40+, with ceiling fan on, and feel comfortable too.

Know what? The issue at coastal places is the high humidity. It is actually the humidity which bothers one more than the temperature. And once the Ac reduces the humidity inside the room to half, one will feel super comfortable. And it will take only about 40 minutes for that to happen.

[thanixravindran]

^^^ There is difference between outside temperature and ambient room temperature. It can be 41degC outside under hot sun but room temperature may be lesser around 35degC influenced by building structure elements like RCC roof, plastered walls, glass windows and ventilation.

And room ACs just don't take outside hot air but recycle inside air. So the temperature difference to bring down to set point like 25degC is quite normal. Even this higher ambient temperature difference matters only during initial condition. Once the room is cooled, it is the rate of heat addition that matters as it is just hysteris curve to manage within few degC.

Most of these parameters are well controlled in night condition (lower room ambient temperature at start up, no frequent opening of closed space, fixed number of people, metabolism rate of human body during sleep) and any brand ACs can easily handle them.

[Gansan]

^^Agreed. When outside temperature is 35 or 36, inside the room it will be 27-30. I have a wall clock in the bedroom that has a hygrometer and a thermometer. Can't say very accurate, but it serves the purpose. I set the Ac temperature a few degrees less than the temperature it indicates. When the hygrometer needle falls to half it's previous level, one feels very comfortable.

[Mortis]

@Thad

My fourth and last Sharp AC has finally died after 11 years. PCB died due to electrical fluctuations and obviously repair or replacement isn't possible.

[Thad E Ginathom]

Originally Posted by Mortis

My fourth and last Sharp AC has finally died after 11 years.

Condolences!

I would have been so happy if mine had lived that long. It was my favourite AC machine!
Looks like you had a better experience of four than I did of one