DaveLee1688

Well, sounds similar. Note that the reply from brand M says that the heater turns on when temperature is above 21 degrees. This is my problem with the heater - In Singapore climax, it hardly falls below 25 degrees, so the heater is ON all the time in standby mode. The Daikin reply seems to be targeted at counties with 4 seasons, which then, I do understand the heater is necessary in that climax. However, in Singapore, if the temperature gets below 21 degrees, the world will be a very different place, and by that time, my worries will not be about aircon but where to get a boat when polar cap melts further to sink Singapore

Those standby power numbers were excerpt from confirmations right from the horse's mouth, via their Singapore office, copied to NEA. On the pre-heating - at no point during the exchanges with the brand M people did condensation came up as a reason. The only reason quoted was the pre-heating is needed for keeping some oil properly separated from coolant, something like this. So it is speculation. On the R22 / R410 tingy- I fully support R410 but I am sure brand M is not the only with using R410. The only reason brand D is not using is because Singapore's law does not mandate it until recently, and probably consumer do not want to pay more. At no point did brand M Japan people quote the type of coolant is the reason too. So it is speculation. I have tried to be very objective in my investigation by first getting NEA to confirm my findings that the condensers are really the culprits. Then, I wrote to brand M people, kind of insisted that they take up the issue with their Japan designers. The findings are their answers to observations I had and they do indeed explain the phenomenon. I did told them that I may share some findings with Singaporeans for the sake of getting to be more energy conscious. Therefore, whether the additional $10-25 per condenser per month means anything to you, matters to you is entirely your call. What I am saying is that all manufacturers should be honest about their green statement, and be true to it, and not just merely appear to be legit quoting some regulations that have not caught up with time.

You interpreted the crux of the issue here wrongly, let me put it another way. Now, if you have brand D & M inverter aircon, if D cost $3200, and M cost $3000, both are inverter aircon. Now, let's calculate based on manufacturer recommended life-span of a condenser, which is 5 years for both brand D & M. Now, if each month, M will consume additional $10 per month because of the need to pre-heat the condenser, it will be $120 per year, and $600 for 5 years. Therefore, brand M will effectively cost you $3000 + $600 = $3,600, compared to brand D's $3200. Now, all inverter aircon will give you 20 to 30% savings in energy usage compared with non-inverter. So, the logic of "inverter aircon from brand M reduce energy by 30% compared with non-inverter, therefore, the standby power can be ignored" is flawed. This logic is flawed for following reasons: a) Not comparing apple-with-apple ; one should compare the installation cost of inverter aircon against another inverter aircon. b) If we argue based on energy saved by using inverter-aircon, then if other manufacturer's technology do not need the pre-heating in a tropical climax to work properly, then, the one that requires it is not environmental conscious as compared to others in the same category. This is especially so because almost all inverter aircon makers advertise their product as environmental friendly. Getting 4 ticks but burning energy in the background is certainly not 'gentleman' like. To give you a feel of what is 80W : When you turn on a Pentium 4 3GHz computer with 1 harddisk, and leave it idle, it consumes about 70 to 90W, not inclusive of energy used by monitor. So, the pre-heating is like leaving your Pentium desktop computer on for 45 (40 + 20/4) minutes each hour, for about 15 hours/day (depending on how long you do not use the condenser) . Do you think this makes sense ? If yes, leave your computer on then, nothing we do to try save the environment will change your thinking.

Confirmations are in: a) The air-condition contains a heater that consumes average 80W for 40 minutes, 20W for 20 minutes each hour when in Standby. b) The past two months of electrical bills reduces by about $50 by switching off the power to 2 units of condensers in the morning before leaving the house, and turning on only at night. There is no confirmation whether this technology which require pre-heating the condenser is specific to Mitsubishi or across all Inverter-based aircon. For me, this thread of investigations helped me identify the source of mysterious energy consumption in my house. For people who are considering installing a new aircon, this is the moral of the story: the amount of standby power consumption need to be factored into the total cost of installing the aircon. If one were to do that, you will realize that over 5 years (the expected life of a condenser) aircon with this technology that requires pre-heating will be at least 20% more expensive than any other Inverter - you need to add in the standby energy consumed. The other thing that I have learned in this investigation is: Singapore's green energy policies are still in stone-age. Manufacturers are conforming to standing policies that are not in tune with the global trends in energy policies. Our government has openly stated the support of green energy, but policies are in the infant stage. Unless citizens proactively encourage policy makers to step on the gas, we will end up being deceived by cleverly crafted advertisement. Unless you are prepared to switch on and off the mains power to the condenser everyday, you better make a wise choice and not take the image projected by advertisements at face value, and ended paying the bills.

NEA used the clamp to measure. However, without actually measuring the voltage and current at the same time, the clamp only indicate RMS value of the current waveform sensed, which include both the real and reactive current (because phase information is missing). What we (NEA and I) did eventually is to use a digital watt meter, which measure real-power only because both voltage and current are measured for calculation. BTW, Singapore mains' voltage is 240V. The current limiting is to meet HDB limits, thereby limiting cooling effect, which does not affect standby power. The problem with Starmex is not only high standby power, but high reactive power at standby - this result in high circulating power. Though Starmex resulted in savings in active usage, for those installations which are not heavily used (infrequent turn on), the high standby power may end up using more energies than, say a non-inverter aircon. Reading some responses here, I come to another conclusion: For those rooms which will have aircon turned on most time of day, inverter aircon may still make sense - the bills saved may well make the high standby power comparatively acceptable. For those rooms where the aircon is for occasional use, inverter aircon may not make sense - you will end up paying and wasting energy for nothing.

Do not bet on this. You need to ask your supplier. Or try googling harder, or go to Toshiba web site and submit an enquiry. The simplest way is this: Switch off all other circuit breakers carefully on the distribution board, go to your utility meter, and read how much energy it is eating up for a few minutes. You will get at least an idea in the order of magnitude on whether it is 10's of watt-hour or just a few watt-hour. Note that the energy meter accumulate in kWh, so, it may not be so easy to see the change if your aircon is good to the environment. For my case, I spend few hundred dollars getting an energy monitor from Efergy to measure. It will pay back in less than 6 months from savings from cutting off the standby power (for me, with 2 condensers, it is S$10 per month). The Efergy eSocket cost S$55 at Sim Lim tower. Be warn that to really measure, you need an electrician to help you. In my case, I am trained to mess with the distribution board 20 years ago during university course, but I do not suggest it to anyone who is not trained to take a wiring apart. Also, for HDB, it will be against HDB rules to mess with the DB. Have a nice weekend, do something than staring at your energy meters :-)

What copper wire size? Okay, I am not an expert in these wire stuffs, but google I can help a bit: For wire gauge, see here Wire Gauge. So, if you read the table, what you should really notice is that for the same wire gauge, the current capacity is dependent on the insulation. For example, number 10 (the usual size for condenser) can carry 30/35/40 Amperes, depending on whether the insulation is rated for 60C/75C/90C respectively. The next larger capacity is number 8 (there is no metric size for number 9), which carries 40/50/55A for the 3 temperatures. So, it will be easier to ask your contractor for better insulation, 75C, than thicker wires because copper wires are very expensive now. If your cable run through the roof like mine, and the copper wire goes through twist and turns to get to the compressor from the distribution board, you need to be a bit 'kiasu' because every twist and turn may reduce the cross-section area of the wire. This is what probably happened in my case, resulting in cable snap under high load. Better get advice from a qualified electrician to have reliable second opinion. Which one has lowest? I really do not know which one has the lowest because none of them specify it clearly. Your best bet is to ask the supplier. However, from hints I get, going for Daikin seems to be a good bet, but again, I am not certain.

Well, I do research for a living ! I always believe in looking for facts. It quite simple, just google with the keyword : +"energy label" +"standby power" and google will do the rest for you.

Based on preliminary findings by NEA staffs, I was told that it has something to do with the design of Mitsubishi's Inverter, having a heater inside to separate some oils. Not sure exactly what this means. I did some research on Internet and retrieved some reports from agencies equivalent to NEA that are responsible for Energy Label in other countries. Based on reports from Australia, Hungary and Czechs, it appears that non-Inverter should not have this problem, but depending on how the electronic controller is designed, the standby power will still vary among products, but should certainly be below 5W. Please also note also that if you have a private house and the copper wire path is quite long, then, it is also safer to use thicker copper wires if you are using Inverter aircon due to the low power factor. One more point: Some might rush off to buy a power factor correction (PFC) device in the market that claim to save energy. Please note that this is largely a scam, it does nothing much to save your energy bill for low-tension household. I found a report by NIST scientists (USA's equivalent of SISIR) dispelling the myths of using PFC to save energy. The real benefit is that it will reduce the large circulating reactive current in the copper wiring, thereby reducing the need for large diameter opper wire. However, for this to be effective, the PFC must be installed right next to the aircon condenser. Therefore, those small PFC device from China on makeshift markets are not going to work, and in fact, may be fire hazards if improperly used. So, be warend.

Well, the problem is not with NEA because all except one equivalent agency in the world has made standby power declaration a mandatory requirement. However, NEA on knowing about this issue has immediately taken action. The problem is really with aircon manufacturers exploiting holes in the system. However, let me also say that apart from the unusually high standby power of Starmex, I am actually very happy about the performance in cooling and savings as compared to the 1-to-1 non-inverter units I used to have. I am caught by surprise on this high standby partly because of my high expectations on "3/4 ticks" systems, expecting them not to waste unnecessary energies. However, I found that those expectations are ahead of most of the world's energy labeling efforts, and hence alerted NEA, and did the posting here so that others will not be similarly surprised. On the issue of turning off the MCB/isolator when not in use, it will work, but carries with it some dangers. I will not recommend it, and suspect why Mitsubishi retracted the suggestion is from a safety point of view (the person who reply is a PR person, most probably their technical people sounded the alert for the suggestion to be retracted to avoid dragging Mitsubishi into legal problems if any electrocution happens as a result). So, installing a separate switch, such as that for the heater, is safer because those switches are designed to be operated by ordinary people and free from leaking switching sparks to the user. Isolator and MCB are designed for technically trained personnel. Not all switches are the same, chose one approved by SISIR capable of switching 20 to 30 Amperes. Having said the above, it is really not a good idea to begin with of having a switch for purpose of cutting off standby power wastage. For new installations, I will suggest to avoid choosing those brands which cannot assure you of low standby power. For those like me who had already installed, we either collective urge Mitsubishi to give us a solution or we help others to avoid getting trapped.

How to select an inverter air con that is really efficient I recently found out that two air con condensers of my house each has standby power of 140VAR, and 25W. This is extremely surprising for a 3/4 ticks energy labeled product. What this means is that even when the air con is not turned on, there will be about 0.8 Amperes circulating in the wiring, which eventually will end up as heat losses. 25W also means that about S$5 per month per condenser will be wasted for nothing per condenser. How I realized this fact is when the utility bill showed significant power consumption end of last year when we went for vacation, even with all applianced turned off. This was about 1 year after I changed 3 Pansonic non-inverter and 2 LG aircons (all one-to-one) to 2 Mitsubishi Starmex inverter aircons, one with 2 fan coils and another with 3. So, recently I bought an energy monitor (e2 from Efergy) and a watt meter (eSocket, also from Efergy) that measures the power of appliances. With these, I discovered the culprits. I wrote to NEA and they were very helpful and responsive, came to my house to confirm the measurements this morning. Last week, I wrote to Mitsubishi, and they finally responded 2 days back to inform that the 140VAR is reactive power that is not being charged by Singapore Power. Nevertheless, the measurements show that the standby power consumption is significantly higher than other manufacturers, basing on my researches and initial data that NEA has collected on this standby power. Based on what NEA staffs tell me this morning, NEA is considering making declaration of standby power necessary for obtaining energy label (the ticks each product gets). Only Australia has made standby power as part of their energy labeling process. If you are planning to install an inverter air con, be aware that you cannot switch off the power to the aircon condenser easily, only way is to go to the power distribution board. Doing so too frequently may be dangerous. What are the alternatives: a) Ask your aircon supplier for information on rated standby power, in terms of real-power and reactive power. The real-power is the wattage that you are going to pay for. A reasonable standby power for electronic controlled appliance should be way below 5W. For example, my Sharp microwave oven consume just below 1W on standby. The way to calculate how much you pay per month for standby power is : (Real-Standby-Power-Rating-in-Watts / 1000) x 24 x 30 x $0.26 $0.26 is the current amount you pay per kilowatt of power consumed. The standby reactive power determine how much current gets circulating in the wire when the aircon is in standby. This has implications on how thick the copper wire must be to prevent fire hazards. For example, two weeks ago, one of my condenser unit refused to start, and the service man discovered after about an hour that the copper wire to the condenser is open circuited. Fortunately, my house has a spare isolator (used to have 5 condensers, now 2), so, he just switched to alternate isolator to fix the problem. In my case, not being aware of the high reactive current issue, the old copper wire for non-inverter condenser was used, probably causing it to snapped during the hot June month when we turned on more frequent and for longer period. b) Ask your aircon installer to install a separate switch for switching the power to the aircon condenser, something like the switch for the water heater (hight current type). When you do not use the aircon, switch it off, just like the water heater. In fact, this 'was' the initial suggestion by Mitsubishi, but they quickly retracted this suggestion by sending another email within a minute. So, the lesson I learned is that saving energy by switching to inverter aircon is not as simple as "buy brand X and reduce $Y", there are some hidden $Z dollars around, and it is going to increase the diameter of copper wires for safety. Hope this sharing will help Singaporean make some wise choices. UPDATE: See Confirmation of findings and Further clarifications