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Prices of the main brands such as Daiken, Fujitsu, Panasonic, Toshiba all vary depending on where it is purchase from; however Daiken and Panasonic seem to be the most expensive.
Found a few place that have good prices on Fujitsu, plus they also have a $200 redemption deal on each unit making them good value.
Are all the brands similar, is Fujitsu cheaper for a reason?
i asked this question to one of the maintenance guys at work who deals with all the split systems [there's at least 100, and all are heavily used]. he basically said that all the Japanese ones are the best, nothing else comes close. mitsubishi was top of his list, it was easy to install and after that they never have any problems.
A lot of people focus on the up front purchase price whereas they should be looking look at the total cost of purchase and operation. The cheaper ones might only cost $10 a month more to run , but over 10 years that more than makes up for price differences. BTW the cost of electricity is also only going to go up. Also, don't trust what the sales staff or the brochures say about energy use. Go and find the Choice magazine reviews, the energy saving costing is one of the few things they do reasonably well.Quote:
Originally Posted by Williamstown
FWIW, We have 3 Daiken split systems and they have run flawlessly over 10 years.
Another oversight, an inverter model running at 100% uses more juice than a constant speed.
I prefer Daikin and the newer Mitsubishi Heavy industries.
Also, make sore you look at the Kw rating for heating and cooling, don't go on HP rating. HP is simply a measure of how powerful the motor is, whereas the Kw rating is a measure of how good it is at heating and cooling, so is far more useful in the real world. When we bought a cassette-style split system, it was more important for us to have heating than cooling, so we bought a Fujitsu system that had a good heat Kw rating.
I also find the difference between a good one a cheap one is the sound it makes. Our current house had a cheap A/C installed before we bought it, and it makes a racket! it creaks and groans as the fins swing back and forth, and even on the lowest setting the fan makes a noise like an airplane taking off!
thats because they have a massively higher output avaialable for shorter periods - my 2.4kw rated fujitsu will do over 5kw heating for short periods - same for cooling - that does not mean they arent efficient - it means they are more flexible and faster at cooling /heating a space than inverters that dont have the facility or versus std's of the sam rating.Quote:
Originally Posted by Timmo
back OT - if its for a bedroom, i would get the most expensive you can find - we got a fujitsu for the bedroom and the fan noise is very quiet, so is the compressor, but the plastic thermally expands and contracts with a cracking noise that sure makes em useless for me while asleep.
there would be no way of measuring this - just depends on how good a quality plastics they use - my guess is that my moms daikan is better in this regard.
for living areas, it doesnt really make a difference - just go for best value - probbaly fujitsu or panasonic.
Our tech people said do not even consider a non-inverter model - its redundant technology and gives much less comfort as it gives a cold blast every time it cycles on and off in heater mode.Quote:
Originally Posted by Timmo
They gave brand preferences as Daikin, Fujitsu, Mitsubishi Heavy Industries, Panasonic, in that order with a strong preference to Daikin. Also commented that Mitsubishi Electrical is a totally different company and inferior to the above.
They also said to look very closely at the efficiency factor and said you should strive for a number above 3.5. This is the amount of heat output per unit of electricity used.
Cheers
Graeme
Inverters, don't believe the hype. Correct sizing of the unit is the single biggest factor that will effect performance. Non point buying a under sized inverter as it will always being running 100%Quote:
Originally Posted by GraemeCook
Also you have to remeber that the main figure you want to be looking at is a unit's COP, this is gives the best indication as to a units efficience. The other thing that you must remebr is that star ratings and the units efficience are based on computer models not real testing. As far as I'm aware only one brand, and they don't make high wall splits use real test results to asatain thier star ratings. Many chinese units have very high star ratings making consumers think they are very efficient, but there is no one regulating or testing these ratings. The only way to test them is in a specifically designed chamber of which there are only 3 of in Australia, 1 which is owned by the company mentioned before. This same company plans this year to use there chamber to also test other brands and prove that many of the star ratings are false, there is a maximum fine of 1 million dollars for a company providing false star ratings.
In saying that I would agree whit above that if you can afford Mitsubishi and Dakin are the top brands out for high wall splits.
Also if you are looking at a cheaper unit remember that R22 is being phased out and supply of the gas will become less as years progress, this has implications if in say 5 years you have a problem with the unit, as the quota will be very low and the gas in short supply the price for servicing these units will be very high and you will prob end up replacing. Spend the money now to buy a R410a unit.
I was referring to the efficiency losses running a dual conversion inverter. DC inverters are not as bad.Quote:
Originally Posted by pharmaboy2
But as stated sizing is critical.
I'm not convinced about Fujitsu, at least not for heating in a cold climate (eg Tas).Quote:
Originally Posted by GraemeCook
Bottom line is at work we have a Fujitsu and last winter it was constantly cutting out on the coldest mornings. I would estimate that this 6kW unit was, after allowing for all the cutting out to defrost, barely producing 2kW average heat output. And with the defrost cycle taking up to 20 minutes the room temperature dropped like a stone.
Everyone I know who has a Fujitsu, with the exception of one massively oversized unit, tells the same story - heat output goes into freefall once it gets down to zero.
Meanwhile at my previous address there was a somewhat undersized 4kW Panasonic. Sure, it ran very hard on the coldest days but the heat ouput never really dropped much. Worst case it would do a defrost for 6 minutes then run flat out for an hour. It was a bit small, but it sure delivered the promised 4kW even with the outdoor unit surrounded by snow.
Others say much the same. Panasonic units work when it's really cold. Run hard, stop for a short defrost then straight back up and running at full output. No messing about, icing up and so on like some of the others do.
End result is that the 4kW Panasonic puts out far more heat when it's needed most than the 6kW Fujitsu does. The air is much hotter and it doesn't grind to a halt for 20 minutes at a time, only to be followed by at best luke warm air.
I know that Daikin also work properly. Not sure about Mitsubishi but most seem to think they are fine.
fair enough. but as with anything, judging an inverter at 100% when its not supposed to run at 100% very often, compared to a unit that only can go at 100% is destined to produce results in line with the std model.Quote:
Originally Posted by Timmo
Personally, i cant believe they are not all required to be tested in a proper controlled room to test output for energy stars - makes the label a little dodgy i'd say
Here are the test requirements for MEPS
As you can see simulations can be used in place of physical tests, a simulation is only as good as the accuracy of the input data. There are only 3 main Chinese factories for generic air conditioners, I garrantee that if these units were put through a physical test many would fail both meps and would be shown to have false energy ratings. This has all ready been shown by 4 corners on units produced by one of the largest factories, Chuan Laung (sp?). The problem is no body is regulating this. Companies are free to make any claim they want about a units performance with the chance of being caught being minimal. To my knowledge LG are the only ones to be caught and that was only after huge amounts of public complaint.
- one unit has to be tested (or simulated) and results supplied with the MEPS application
- a physical test in a calorimeter or the enthalpy method is acceptable
- a simulation to AS/NZS 3823.3 is an acceptable alternative to a physical test where this standard covers the product type and configuration
- cooling capacity and energy consumption is determined to condition T1
- heating capacity and energy consumption is determined to condition H1 (ISO condition "high")
- for each unit tested, the measured capacity shall be > 0.95 of the rated value
- for each unit tested, the measured energy consumption shall be < 1.05 of the rated value
Agreed they should be tested.Quote:
Originally Posted by pharmaboy2
One problem with some inverters though is that the thermostats are outright dodgy.
Say you set it to 22 and it's in heating mode. Obviously if the temp drops to 21 then you want the unit to do whatever it takes to bring it back up to 22. If that's running at 100% constantly then so be it, you want 22 not 21.
But some cheat. They'll never run at 100% unless there's a big gap between the setting and actual room temperature. And so the only way for the consumer to get the unit to work properly is to set it warmer than they really want - with some you literally need to set it at 28 just to get full output in a 21 degree room and warm it to 22.
All split systems ought to be limited to a normal operation temperature variation of +/- 1.5 degrees otherwise they fail MEPS. That is, if it's set to 22 then at the very worst it ought to be at full output at anything below 20.5 and at full cooling output at or above 23.5
Ideally, a narrower range is desirable as this will reduce energy consumption - most people set thermostats to maintain comfort at the minimum point in the cycle (in heating mode) so the less accurate it is, the more over-heating takes place. Given that a simple bi-metal thermostat has a range of less than 1 degree for a quality unit it's not difficult to do. For that matter, a simple Dick Smith kit keeps my fish tank within 0.1 degrees. So a $2000 air-conditioner ought not have temperature variation of 6 or even 2 degrees from the set point.
3 degrees from hottest to coldest (that is, hottest point in cooling mode to coldest point in heating mode including the changeover) is pretty well accepted as being about the limit for comfort. Hence +/- 1.5 is the practical limit from the set point for a reverse cycle air-conditioner. And since most measure the temperature quite close (or in) the machine itself, that reduces the margin even further.
I was sold on Fujitsu given the price and $200 cash back at the moment, esp their 9kw multihead unit. I'm now thinking about Daikin or other given the comments. Daikin have a multihead unit that can take upto 9 heads (18kw cool, max) which would be enough for the whole house. Would add just 2 heads now (8kw and 2.5kw) then add more as required. The heads are relatively cheap (converter around $4.5k), so for 2/3 heads price is similar given dont' need electrician to run separate circuits, etc.
Only thing I' m not sure about, is what happens if I run a single 2.5kw head from a 18kw inverter unit (when other heads are not on), will this use more much more power then a 2.5 inverter condensor?
I don't like the idea of having 3/4 condensers outside.
Multi head systems don't have to meet any MEPS standard what so ever as they are yet to draw up regulations for them. Im not saying they are bad just something to be aware of.
The shortfall of proportional only control loops. Inverters really need to be driven by P.I or P.I.D control to make the most out of their capability.Quote:
Originally Posted by Smurf
Installed a 4 1/2 star 7.1kW MHI unit in Jan, runs like a dream, very powerful and quiet - also got a great price on it so was very happy.Quote:
Originally Posted by BobL
Until....... I copped the my first power bill of $550. :oo: Up from about $120. Now there were a few hot weeks in melbourne but most of the time I had the thing on economy mode and set the temp to 24C, only had it on once overnight.
Since the power fees are going up 17% I would advise people to rethink. Spend the money on isulation. Im thinking of replacing the doors with vaccum chambers and boxing in all my windows.
From reading the posts it seams to come down to a decision of invertor or not
As an Engineer who has dealt with serviced and maintained ac units for over 30 years , (though much of that was before invertor systems) and having both a split system ( for the extensions) and a fully ducted system for the main house I am yet to be sold on the economic advantages of the inverter Ac units.
As for brand there is obviouslly little between the top brands so my advice would be to go with the best and easiest remote controle unit, Now this may sound silly but a remote that is easy and simple to use is proberly more important than a complex one when the output of the AC is close to the others :2tsup: