Maybe use chiller lah.

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Added on February 7, 2012, 6:07 pmFor easy calculation, i always use 1hp = 1kw, 2hp =2kw. This include losses and buffer.

This post has been edited by weikee: Feb 7 2012, 06:07 PM

For rainy day, setting 25c is actually wasting energy. Why because outside temperature can be lower than 25c.

For much saving, get a ceiling ventilation, and switch it on during rainy day. This will suck in fresh and cooling air. Much more saving.

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Added on February 7, 2012, 7:04 pmAlso my calculation per your reply earlier.

899 1hp
1268 1hp inverter
2199 2.5hp
2699 2.5hp

So let say using http://www.jintexelectronics.com/ pricing, and say all compressor run all the time for easy calculation.


1HP Panasonic standard non inverter = 788
2.5HP Panasonic non inverter = 2199

1HP Panasonic Inverter = 1268
2.5HP Panasonic Inverter = 2699


For Non Inverter:
3x 1hp, + 1x 2.5hp
Total investment = 4563

Assume 1hp = 1kw, 2.5hp =2.5kw
Monthly running bill = (3kw x 8 x 30) + (2.5 x 8 x 3) = 720 + 60 = 780 Kw / month * 0.40 (using 40 cent per watt) = RM 312

If run for 24 months = 312 x 24 + 4563 = RM 12051.00




For Inverter
3x 1hp, + 1x 2.5hp
Total investment = 6503

Assume 1hp = 1kw, 2.5hp =2.5kw
Monthly running bill = (3kw x 8 x 30) + (2.5 x 8 x 3) = 720 + 60 = 780 Kw / month * 0.40 (using 40 cent per watt) = RM 312
(Say 30% saving based on Panasonic website) = RM 312 - 30% = 218.4

If run for 24 months = 218.4 x 24 + 6503 = RM 11744.6


So the saving for 24 months is 306.4

Here some of the things to consider
- Inverter piping are more expensive to install,
- Don't forget, this is as per claim by manufacture, at maximum saving. Which when you set temperature to 23c the saving may not be that much.


So the real saving is maybe after >30 months






This post has been edited by weikee: Feb 7 2012, 07:04 PM

I been using a/c for long, and ventilation too. Fresh air is still the best especially after rain.

A/C need humidifier to make the air humid, if not some people find the throat too dry, and my wife is one of them.

Something must be very wrong with your panasonic. I set temperature of 22 sometime 20 in my previous room a/c and it run like 10 hours a day, and my mom had an old National A/C. House with 1 medium size fridge, and one freezer for business. we pay like 180 to 200 a month. Now that i no longer leave they, they pay about 150+-

Look like your panasonic is running non stop.

A true inverter can go from 100% load to 20% load, it can be 80%, 70% or even 60% depend on room and external temperature. That is why we need signal wire to drive the inverter compressor and motor speed.

I am giving calculation assuming all at 1KW, with per claim by manufacture "Panasonic" giving 30% better efficiency for easy calculation.

The lower you set the temperature, you get less efficiency.

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Added on February 7, 2012, 11:49 pmInverter do reduce power consumption, but not heavy and earth difference for all situation and usage. People like me using 23c lower will not see 30% as claim by manufacture.



This post has been edited by weikee: Feb 7 2012, 11:49 PM

When i use a/c it must be 23 or lower. To me 24 and above is stuffy, i rather use ventilation + outside air. If 24c can work for all, why inverter a/c allow users to set temperature <20c?

The further between Compressor and blower unit, you need to increase the HP. But for house 10 to 20 feet is not much a problem. In one of my office oversea, we had compressor and blower distance of 7 floors. That we need to increase the HP by 50%, as recommend by HAVC expert.

It can be difference if the thermostat is not calibrate correctly.

22c non inverter will flipper around + 2c (maybe more not too sure).

25c for inverter will flipper but less than non inverter. But 25c is still 25c is not same as 22c.

E.g. If i go get myself a inverter fridge, and set it to 1c, ice still melt because is not 0c. You cannot say inverter 1c = non inverter 0c

Fridge and A/C use similar concept. And Fridge still use temperature and Celsius for measurement.

Less pressure use in R22 does not mean longer time to cool, R22 have lower vapor pressure. And R410 or R22 does not made much difference, actually R410 performance degrade when external temperature increase.

Source - http://fire.nist.gov/bfrlpubs/build02/PDF/b02186.pdf

R22 and R410A split air-conditioning systems were tested and compared as outdoor
temperature ranged from 27.8 °C (82.0 °F) to 54.4 °F (130 °F). The R410A system tests were
extended to 68.3 °C (155.0 °F) ambient temperature with a customized compressor. When
outdoor temperature increased, the R410A system performance degraded more than the R22
system performance. While capacities of both systems were approximately equal at the 35.0 °C
(95.0 °F) rating point, at the 54.4 °C (130.0 °F) outdoor temperature the R410A capacity was
9 % below that of R22. For the same test points, the R410A COP (EER) was 4 % and 15 %
lower than the R22 COP (EER), respectively. The degradation trend was linear. Since both
systems employed identical heat exchangers and similar design (scroll) compressors, the
refrigerant and lubricant used in each system had the dominant effect on the measured results.
Operation of the R410A system was stable during all tests, including those with the
customized compressors extending up to the 68.3 °F (155.0 °F) outdoor temperature and
resulting in a supercritical condition at the condenser inlet. No noticeable changes in noise level
or operation of the system was noted.

I been using this method for many years. So far all the a/c still good. Only one die due to old age.

26c, that is way too hot for the compressor to run non stop even slow down. Try set to 23c, you see compressor running constant with variable speed.

26c, better use natural air outside in the evening. Way to stuff for me. Maybe is only me. I use A/c for <=23, else i just off it.

SS2 Legend.

Sharp, so far so good Cheap too. about 800+- when I brought one.

So lucky.

If room is mid size, 1.5 is not bad. It may not use extra electricity.

You plan to use 16c? I think anything below 20c is not easy to achieve unless you oversize your a/c. I have try 20, 19, and 18 all feel the same to me.

All the item I buy at legend using cc no interest. I pay half using cc another is cheque.

He first calculate cash term, than I told them I need best price. He give me the best best price. Than I ask can pay all in C.Card because I can't bring so much money walking around? Cannot woh, but he can cut the deal for 1/2, 1/2 payment. C.Card and Cheque on Delivery. So all my things are c.card 50%, and cheque when they deliver to my door step.