Split Aircon Deal - Central Aircon Is Killing Us

justanick on 16/01/2024 - 03:14

Hi All,

We have over 10 year old ducted Mitsubishi Mr Slim aircon which is currently sucking up 53kWh from our usage of 7pm - 10am. Our 13.2kW solar panels aren’t producing anything during this period.
Our main use is in our bedroom during the night.
We are now considering installing split aircon capable of cooling the master bedroom during majority of the months and keeping warm during winter. It needs to be energy efficient.

We really can’t fork out a lot after Christmas vacation and need to use our Latitude Card for 36months interest free purchase.

What are our options? Which brand shall we pick and from where? Ideally need installation on double brick single storey house which has three phase power.

Please help us before our power bills become too much to bear.
My wife has a condition that requires certain temperature.

Electrical & Electronics Air Conditioner

Comments

  • Malik Nasser on 16/01/2024 - 07:39
    +9

    So you are using 53kWh in 15 hours, which is an average power use of 3.53kW.
    The issue is not your aircon system but your insulation (or you leave all your windows open whilst the aircon is running).
    You aircon should only come on if the temperature rises above a set point. The only reason the temperature rises is due to thermal energy coming into your house.
    You need to look for the root cause of the issue, and not blame your aircon system. It is only doing what you have asked of it. Sort out your houses thermal inefficiencies, and the rest will take care of itself.

    • Lichen6420 on 16/01/2024 - 08:05
      +8

      This does not negate the fact that a central A/C is cooling/heating the entire house, or the minimum amount of zones for that unit.

      A split can cool/heat just a single room (the master) which is all they need and is inherently more efficient.

      In my experience Mitsubishi Electrics are bulletproof.

      Get quotes through an installer for supply and install and compare with buying a unit yourself and paying someone to install.

      • boomramada on 16/01/2024 - 09:03

        This issue can easily fixed by adding zoning + adding an extra temp sensor to the master bedroom or somewhere that needs more cooling.

        • djkelly69 on 16/01/2024 - 14:52

          Genuine question - is it easy/expensive to add zoning and/or temp sensors? We have ducted with no zones, and it is definitely something I would consider if plausible.

          • boomramada on 16/01/2024 - 15:07

            @djkelly69: Easy .. , not cheap.. depend on the brand. Just get a quotation from the installer.
            Then installer point out, if no one in the room, just close the vent lol

  • Lord Fart Bucket on 16/01/2024 - 08:02
    +3

    You're based in Sydney, according to your profile. The night time temps in Sydney aren't such that you need to have an aircon on, in my view. Yes, it's been warm a few nights… but i just blast the aircon for 30 minutes before going to bed… when i am asleep, it is off.

    As Malik said, your aircon is fine. Check your insulation or adjust your comfort level. It's cheaper than a new aircon.

    • Jimothy Wongingtons on 16/01/2024 - 08:34

      His misso has a health condition he said so maybe the need to run it mega cold

    • CyberMurning on 16/01/2024 - 08:49
      -2

      blast the aircon for 30 minutes before going to bed… when i am asleep, it is off.

      correct and set timer to on again at 3pm for 30mins then off. enough

      • knobbs on 16/01/2024 - 10:14
        +1

        My friend what are you getting up at at 3pm in the bedroom?

        • Chandler on 16/01/2024 - 12:07

          My friend what are you getting up at at 3pm in the bedroom?

          I think you know what they're getting up… (☞ﾟヮﾟ)☞

  • FezMonkey on 16/01/2024 - 08:07

    Somebody posted the other day about being able to borrow a thermal camera to help show the spots around the house you are losing efficiency.

    • bargaino on 17/01/2024 - 10:52

      Not as quick, but an infra-red thermometer will do it too. Kind of like a 1-pixel thermal camera :)

  • payless69 on 16/01/2024 - 08:21

    Central units are usually the dead quiet ones. Drawbacks are duct buildups.
    Insulation works if your window stays shut.

  • geekcohen on 16/01/2024 - 08:43

    You need to weigh up the costs of running your current unit vs the investment of a new unit that might be more efficient plus its running cost.

    You might be better to buy a portable unit which could cost less to run plus a smaller investment.

    If you are already struggling and having to use a credit card, then buying a new unit is going to be a big cost, so could stretch things even further.

  • Dollar General on 16/01/2024 - 09:07

    Maybe a battery for your solar is a better option, depending on rebates in NSW

    • JimB on 16/01/2024 - 09:18

      50kw of batteries are expensive.

      • Mechz on 16/01/2024 - 13:15

        New Ford F150 Lighting on a novated lease? Two birds one stone etc.

  • JimB on 16/01/2024 - 09:35

    unless your bedroom is exceptionally large, a small 2.5kw split system will be sufficient.

    For long term reliability, I've had good experience with Fujitsu, Mitsubishi and Panasonic, e.g. any Japanese brand.

    It may cost a couple of hundred more, however when installation is so expensive, it's worthwhile to buy a good unit.

    I remember you were able to purchase 2.5kw units for $600 after cashback.. these days there are no deals, they are circa $900

    • netjock on 16/01/2024 - 10:16

      I think few OzB people might have a uni lying around. Buy now, questions later type of thing

      • JimB on 16/01/2024 - 10:18

        lol… it's gotta be cheap cheap to buy a unit just in case you want to use it in future.

        Then again, I've more than a few unused power banks and USB chargers.

        • netjock on 16/01/2024 - 10:21

          LOL. Get a 5 year warranty unit. Buy it at year 4 for the current unit and see how goes. Air cons are like the Teslas of the cooling world.

          • JimB on 16/01/2024 - 10:24

            @netjock: I think all brand split systems have 5 year warranties.. even the cheapest Kogan units.

            Getting spare parts/repairs for a no-name air cond out of warranty is another matter, hence why it's worth paying more for a good brand.

            • netjock on 16/01/2024 - 10:25
              +1

              @JimB: True.

              But when you think the call out charge is $200 then they will charge you another $400 to come back with spare parts etc.

              Might as well get a new unit.

    • bargaino on 17/01/2024 - 10:53

      unless your bedroom is exceptionally large,

      Or window open, or no insulation. Something like that is happening for OP to be using so much power.

      • ozbs25 on 17/01/2024 - 11:47

        They are setting it to 19C though. Surely that will make a difference compared with say 25C.

  • BiotBargin on 16/01/2024 - 10:20

    get the filters cleaned and shut off the ducts to the parts of the house not requiring air-con. your current unit might also be down on refrigerant or has non-condensables in it - both will causing it to work harder so regasing might also help.

  • netjock on 16/01/2024 - 10:20

    53kWh from our usage of 7pm - 10am

    We have our air con at 25C, we also check the temperature at what time it cools down, open the correct doors and windows, use cheap $50 fans to move air around the house to cool down. Then we close all our windows around 8am to keep the heat out. (Melbourne)

    That said since you have ducting in place maybe consider putting in an evaporative unit as it might be cheaper (I am from Melbourne so not sure if it would work in Sydney)

    We have 2 aircons. 2.5kw and 3kw. Only a 8 sq house (3BR) at both ends and with don't have to use both units on 30C days, use a few fans to move the air around. Aircon fan at 2 (out of 4) uses about 1kw per hour.

    You really need to look at your floor plan to see what is best for your house. Maybe find a similar plan and throw it up for people to give an opinion.

    • MS Paint on 16/01/2024 - 11:22

      Only a 8 sq house

      Surely you mean 18 at least?

      • JimB on 16/01/2024 - 11:44

        It could be a 8sq house.

        They were fairly common back in the day, just don't expect an ensuite.

        A 3 bedroom 72sqm apartment would be considered large here and a mansion in many parts of the world.

        • netjock on 17/01/2024 - 11:48

          Built 2000. Luckily the owner built it a bit small on a 720m2 block.

      • Stewardo on 16/01/2024 - 12:24
        +1

        8 Squares = 74.5 m2

      • netjock on 17/01/2024 - 11:48
        +1

        Nah. Why do you need any bigger? You fill it with more stuff?

        I use like 5kwh in winter (with 1 air con to heat rather than gas central)
        2kwh a day net in summer

        This year my electricity cost will be zero after OVO pays me 10c/kwh with a 6.6kw (solar with hated Growatt inverter)

        Home insurance is cheaper to because cost to rebuild is low. Also 100m above sea level and not near a river, no flood insurance or opt out required.

        • JimB on 17/01/2024 - 12:09

          Yeah, I've lived in houses from 13 squares to 50 squares.

          I was just as happy in the 13 square home as I was in the 50 square home.

          Now, current house is somewhere in between. Too much cleaning in the 50square home.

          • netjock on 17/01/2024 - 14:41

            @JimB: My parents live in probably 15 squares maybe 20 squares. They just end up filling the space with crap because they think they have a use for basically anything and everything

  • justanick on 16/01/2024 - 12:58

    Let me elaborate our problem a bit more here. Our aircon only cools when the temperature is set at 19 or 20 anything above it just works as a fan. I called two different companies costing me $300 each time they said the unit is very old better to replace which will cost $10-15k. Where the temperature sensor is I’m not sure and it only has two zones either all bedrooms or the entire house.
    They also cleaned the filters and checked the ducts there are no leaks. It’s a double brick house so insulation isn’t a problem.

    It seems the aircon is always on full blast which is causing the electric bills to sky rocket.

    I called Daikan they gave me a quote of $2000 for a split unit Alira 2.5kw $2150.

    What are my options folks? Sorry the option of turning on for 30mins and turning it off isn’t an option for my wife.

    • Mechz on 16/01/2024 - 13:17

      Do the duct openings in the ceiling not have a close function? So you can stop the air coming in unnecessarily.

      • justanick on 16/01/2024 - 16:46

        Nope. They are like square vents always open. I looked online if I could get a cover to block the rooms that doesn’t require cooling but couldn’t find them.

        • Mechz on 16/01/2024 - 17:16

          Get those replaced with ones you can screw or twist to close. Much cheaper than another unit.

    • ozbs25 on 16/01/2024 - 13:18

      Is there a way for you to add this info to your main post? 19 or 20 seems very low. It probably changes a lot of things? You don't want to know what we set ours to when we use it.

    • boomramada on 16/01/2024 - 14:19

      Buy a small thermometer, put it where the duct is, right at the entrance. Then set the AC to 18c and check how cold it gets.
      If it's not 18c, that's mean AC need re-gas//fix/service/replaced etc.

      Otherwise, you need a new house with good insulation.

      Or you could just buy a split system to your bed room. Choice is yours, just pick the option cheaper for you.

    • netjock on 17/01/2024 - 11:51

      Our aircon only cools when the temperature is set at 19 or 20

      Something wrong with your aircon.

      I'd look at getting smaller units and figure out your air circulation as it is sub optimal.

      $10k - $15k to replace. That is what puts me off buying a property that has it. Some people see value but fingers cross it doesn't go wrong then you need to lift the roof and crane the thing out.

      Kogan was selling 2.5Kw units for like $500 a pop. Try to get it $600 installed each. You'll have like 9 units with spare change. 1 for each lounge, dinning, kitchen, study, 5 bedrooms. If you only have 4 bedrooms chuck one in the garage!

  • zoob on 16/01/2024 - 17:17

    Would a ceiling fan work for you overnight? DC fans are dead quiet on lower settings and use very little power. Also, what sort of insulation do you have in your roof? These would be far more cost effective things to try compared to new splits or running the aircon all night

  • justanick on 16/01/2024 - 17:26

    This was already done. The aircon doesn’t get below 19C. Some of the rooms get 19C but others vary specifically the master bedroom.

  • justanick on 16/01/2024 - 17:27

    Can you guys let me know the average cost for installing split aircon and aircon?

    Is it going to be possible to get an aircon and installed for $1000? Daikan was $2100 it seems a bit too much.

  • GourmetFoodie on 16/01/2024 - 19:52

    I never found split system cheaper.

  • justanick on 16/01/2024 - 20:43

    Ya it seems more but we just need this for our master bedroom.

    Any clue on price and installation? I’m getting a quote of $1800-2400 - Daikan

    • ozbs25 on 16/01/2024 - 23:05

      I've helped organise the installation of two split systems in the last few years. Sorry not sure on the size but they were for two different master bedrooms and both were about $1800 installled.

      • justanick on 17/01/2024 - 02:46

        Each unit was $1800 installed? Do you have the brand and model number?

        Option 1:
        I got a quote today for installation $650+GST
        The same guy quoted me $1550plusGST for Daikan Ftxf25w.
        Option 2:
        Buy the unit from Goodguys or Harvey Norman with Latitude card and pay $650+GST for installation.

        Is there an efficient aircon unit that I could buy through either of the two retailers?

        • ozbs25 on 17/01/2024 - 10:45

          Sorry not sure on the model numbers but:

          $1925 Mitsubishi Heavy Industries 2.5kw inverter, reverse cycle high wall split system.

          $1769 Mitsubishi 3.5kw air conditioner

  • yolohobo on 16/01/2024 - 23:26

    Our main use is in our bedroom during the night.

    It's worth keeping in mind that the noise level of the average split system would be difficult for most people to sleep through.

    Especially given you're coming from a ducted system where noise isn't an issue.

    You'd want to focus your search on a low to very low noise unit.

    • justanick on 17/01/2024 - 02:47

      The noise should be okay. We both grew up overseas which has high dependency on split aircons.

    • bargaino on 17/01/2024 - 10:58

      What noise? Are you installing the compressor indoors? :)

      The only indoor noise should be the barrel fan, which is very quiet, and soothing white noise. You don't need it on high speed.

      I prefer a ceiling fan, but Sydney can be humid in summer.

    • lgacb08 on 18/01/2024 - 12:11

      Only if you have bad installation (back to back with the compressor right behind the wall where your bed head is. Once it reach the temperature (15 min) it will be dead quiet.
      Ducted will be noisy if you close the bedroom door due to positive air pressure pushing through the door gap.

  • justanick on 18/01/2024 - 00:38

    Thank you for your kind suggestions. It really helps.

    We re-gased when the mechanics came in November and cleaned the filter.

    We don’t know how to replace those square vents with replicas that can be shut.

    The Daikan model which I gave is it a bad unit? I can’t get it cheaper than $1550+GST.

    The problem with our ducted system is that the compressor doesn’t cut off at all.

    • lgacb08 on 18/01/2024 - 12:17

      You can't get any cheaper for a decent unit, simple. MHI unit is around $900 at Bunnings, $650 for installation is about right.
      You should get your priority in life sort out properly because at the current rate the ducted cost you $500 a month to run, get a family loan, sell your kidney or do whatever it takes because you can recoup the cost in 4 month time.

  • justanick on 20/01/2024 - 22:55

    Thanks mate. Are you recommending split AC in our bedroom or changing the current system?

    If you are recommending split unit then this guy quoted us Daikan Ftxf25w $1550+GST. Is it good enough and shall we get it?

    • lgacb08 on 22/01/2024 - 13:53

      That is the lower end model from Daikin, cooling only. Why don't you go back to him and get the one with heating too. Daikin is a good brand but if it were me I'd just up it to the cora series.

      • justanick on 22/01/2024 - 23:50

        Thanks mate. I went back to him today and he responded that model has both heating and cooling. I’m happy to use him as an installer if he can’t give me good deals.
        How much is the Cora series? I went to Daikin site they will refer to their technicians.

        Is there a place where I can find Daikin aircon prices?

        The model he gave me shows reverse cycle not sure if I’m not looking at the right number.

        https://www.daikincatalog.com/das_0010/book/#target/page_no=…

        Most importantly with a split aircon how much kWh will it consume over the evening/night let’s say 10 hours?

  • justanick on 23/01/2024 - 14:39

    Guys we are closing in with our decision. We will use our existing Latitude card and purchase the aircon. I called Harvey Norman and penciled the below two models. Installation back to back is $499.

    1) Is Mitsubishi or Fujitsu a better choice? The Fujitsu has pollen filter etc not sure if it’s gimmick.
    2)
    https://www.harveynorman.com.au/fujitsu-2-5kw-lifestyle-rang…
    3)
    https://www.harveynorman.com.au/mitsubishi-electric-msz-ap-2…

    • lgacb08 on 23/01/2024 - 21:28

      If money is tight, why don't you go for something cheaper? There's a Panasonic unit of similar size on sale at Harvey Norman for $960 and that one also has wifi built in. All those Japanese units are good choice with enough reliability behind their name.
      Also can you use that card at someone else other than HN? Bunnings sells Mitsubishi heavy industry unit around $900 mark.
      Also not going to have a ditch at you but you're picking a terrible credit card to go with, if I'm not wrong that card is a scam devised by Gerry Harvey and you'll be paying a decent chunk of monthly fee just to get that interest free period.
      As for energy consumption a 2.5kw unit will consume at most 0.9kwh in the first hour and depending on your house insulation it won't be over 0.5kwh after that.

  • justanick on 23/01/2024 - 22:25

    Bunnings unfortunately doesn’t take Latitude interest free card.
    Latitude card is accepted in many stores including GG, HN, Amart etc. We bought furnitures and pay $10 a month account keeping fees. The only good thing is they offer 60 months interest free so we just have to pay $19/month provided we ensure we pay every month (which we do).

    What’s the difference between Mitsubishi Heavy industry unit vs the one I posted from HN? Does heavy industry mean a higher grade?

    We would like to stick with Japanese units as they would run for years. My experience with Panasonic and Samsung aircon were bad.

    • lgacb08 on 24/01/2024 - 07:21

      I've had both Panasonic and Mitsubishi heavy and they're excellent. If your experience is relating to ducted then it might not be the case for split, all Japanese brand splits are much of a muchness anyway. Ducted issues is more because of installation and incorrect zone controller than the unit itself.
      unless you're already paying $19 a month due to on going balance with latitude (which is bad financial practice in itself), spending $1000+ on the card is the worst decision right now because that translate to 20% annual interest, there are many other better credit card products with lower fee and you don't get tied up to buy overpriced products from Harvey Norman and keep supporting that guy.

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