Recommendations for Ducted Reverse Cycle Air Conditioning Units

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  Overclocked91 on 15/08/2025 - 07:35

  Daikin, Mitsubishi Electric or HI. All have good after-sales service/in-house warranty and generally easy access to replacement parts.

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  KillBotFactory on 15/08/2025 - 10:12

  I've read in a few places that the high capacity ME units can be unbearably noisy.

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  Carussell on 15/08/2025 - 11:59

  We have had our Mitsubishi Electric reverse cyle ducted installed in 2000…it still runs sweet today.
  It is an old school 3 phase system NOT a single phase inverter type.
  Based on that performance I recommend a Mitsubishi.
  ** we do get it serviced every 2 years

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  JimB on 15/08/2025 - 13:39

  Other than Haier, the above brands are all good, it's just based on preference and the quality of the installation. I'd pick one that can ramp down the lowest.

  Personally, I'd ask the recommendations of the installer you are using, e.g. how often they install them and if they are warranty agents for that brand.

  Could be the best brand in the world but if they haven't used it before, you're better getting a brand they install frequently.

  Personally for a 173 sqm house, I'd go 18kW because they generally can ramp down lower than a 20kw model can. a 18kW should be able to do the whole house at the same time too.

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  AaRodz on 15/08/2025 - 15:56

  +1

  Thanks everyone for your helpful insight,

  Was looking at ramp downs
  The ME models ramp down to 4.9 kW (EER 3.20 / COP 3.92 combined average - 3.57) and (EER 3.07 / COP 3.75 combined average 3.41), which is impressive but as can be seen the EER and COP numbers are not as good which is weird as you think the EER (energy efficiency reading) and COP (Coefficient of Performance) would be better as it ramps down to 4.9 kW which equates to 27.2% and 24.5% ramp down for cooling / 24.5% and 21.9% ramp down for heating for the the 18kW and 20 kW models.

  The next best is Panasonic ramping down to 5.5 kW cooling and heating (EER 3.32 / COP 3.75 average - 3.53) for 18kW model and 5.7 kW for cooling and 5.5 kW for heating (EER 3.33 / COP 3.67 average - 3.5) for the 20 kW model. The ramp down percentages on these are 30.6% (18kW) and 28.5% (20kW) for cooling and for heating it is 27.5% (18kW) and 24.6% (20kW)

  The MHI goes down to 6.9 kW for the 20 kW (EER 3.46 / COP 4.12 average - 3.79 ) - these have the best EER and COP but not so good on the ramp down percentage of 34.5% (cooling) and 30.80% (heating).

  For all the talk on the market that Daikin are one of the best as they only specialize in air cons, it only ramps down to 9 kw (18kw) and 10kW (20 kW) models.

  Wondering what figures to consider, the ramp down percentage or the EER/COP numbers to make an informed call on choosing the right unit.

  In addition do I need to be concerned about the air flow on these models as in the minimum and maximum l/s for when using only a single zone and vice versa when using a lot of the zones at the same time. Again some brands give you these numbers but not all of them - some have nominal and maximum airflow.

  What rating for the ducting is recommend and does is make much difference, R1.0 is recommended but is there any real value in using R2.0 or more, it will be understandably more expensive for the higher R2.0 but is there a real value for the added cost of upgrading to this higher rating ?

  Also understand the need for a good installer and easy parts availability plus proper warranty on not only the unit but also on workmanship and other parts like the ducting used.

  I have put a lot of questions forward but trying to make the most informed decision before purchasing, look forward to more insight from the wonderful ozbargain community on the above, thanks.