Received my new thermometer and tested with it again. Readings are coinciding with that of old cheaper thermometer. If I summarize it in one line what Panasonic does is it raises the temps by 1.5 C over set temp but it has the corresponding power draw as well.
With new thermo I tested 1st eith 26 C. Room temp dropped at 25.4 C in 15 minutes only. On 20th minute motor slowed down to 1.5 amps to let room temps raise to 27.6 C remained constant there. Sensible cooling difference felt a lot and the feel was as if AC had tripped but it wasn't the case. Real 27 plus room temp doesn't quite feel like AC chilled room as per our people expectations. Better call a neutral situation as per room temps where you can sit and talk but if you move around you feel slight heat at your face then you look at AC if its working ? Kind of like that... Tried to explain in best possible way...
Then 2nd test at 25 before last night sleep. Took max 9.1 amps in acceleration. Temps dropped to 24.2 C fast in max 20 mins. Motor kept slowing down and by 25 minutes past it was at 2.0 amps. Room temp read at 26.4 C and sometimes fluctuate to 26.6 C. Both tests were without fan. As I was preparing to sleep I switched on fan on low speed. Ceiling fan causes sensible cooling to very good just as per expectations. In the morning today, amp draw was at 1.6 amp but room temp was solid 26.6 C before I turned ac off. Reason: walls, ceiling had been cooled down just enough.
I have also done cooling at 16 C few days ago. It just didn't stop as Ac was not able to reach set temp even in an hour. It went max 9.5 amps and after an hour it was still at 8.8 amps. Room temp it achieved was 18.2 C. I aborted the test then. Room felt freezing cold though.