(Solved) How to Separately Meter Air Conditioner Use?

LCusacka on 24/12/2020 - 11:44
Last edited 24/12/2020 - 20:50 by 2 other users

Seeking advice from an electrician:

I rent out a room downstairs that has an air conditioner. I include electricity in the price of the room.

However, some tenants use the air conditioner only occasionally, while others leave it on all summer.

Rather than increase the price of the rent, I'd like to charge for the electricity used for air conditioning.

I want to install a hardwired meter for the air conditioner. I understand that if the air conditioner is separately wired I can put a meter in the sub-board, but this is located upstairs so the tenant won't be able to check their usage.

I would like to install a wall-mounted meter next to the air conditioner itself. I will get an electrician to do this, but I want to work out what is possible first.

Can you please confirm if the following is possible:

Could the electrician install something like this in the wall
Then inside that, install a meter, such as this one

Alternatively, is there another option for some sort of wall mounted meter that can be used to record usage?

Thanks for your help.

Electrical & Electronics

closed Comments

  • charzy on 24/12/2020 - 12:04
    +1

    I include electricity in the price of the room.

    Perhaps share the bills. Then everyone will be more conscious about their usage.

    • Cusacka on 24/12/2020 - 12:06

      Thanks for the advice. One option is for them to pay a % of the bill, but then they would be thinking about how much electricity we are using upstairs and whether we are using too much aircon. I think that makes it a bit too complicated - I don't really want their bill to be determined but how much electricity we are using. Thanks anyway.

  • FoxJump on 24/12/2020 - 12:09

    I had an LG a/c that would tell me its usage in kws.

    • Cusacka on 24/12/2020 - 12:10

      That's useful - this one is getting pretty old so replacing it with one that also records usage could be a good option.

      Did it record cumulative usage or just usage at any one point in time?

      • FoxJump on 24/12/2020 - 13:29

        I am not sure. I don't live there anymore.
        however where I live now, the Daikin does give a graph of usage, per day, per week, per month.

        The LG one would even let me cap the usage to a certain inverter output so .. I could ask it to cool with less power usage - and less cool.

        If I ever buy a new A/C, it having WiFi is an essential feature.

  • MrHyde on 24/12/2020 - 12:34

    I've been in the market for a solar panel installation and one of the options is a Solar Analytics consumption meter that is installed in the switchboard (or thereabouts). It can measure consumption by switch and you can view that information by a website/app. Maybe something like that.

    • Cusacka on 24/12/2020 - 13:19

      Thanks, I think what you are describing is a sub board meter. This option would definitely work, but they don't have access to the sub board so wouldn't be able to track their usage and to check it would need to come into my private part of the house.

  • hothed on 24/12/2020 - 12:53
    +1

    Does the aircon plug into a GPO?
    If GPO. Get a power meter from dick smith/bunnings/kogan/ebay. Super glue to powerpoint so cant be unplugged, superglue plug into face of meter.

    If not, is it on a dedicated circuit (or are other power points on the same circuit)?
    If dedicated circuit, you can install meter at subboard on din rail (if you have space).

    I would go the top option.

    • Cusacka on 24/12/2020 - 13:01

      Thanks for this. It is plugged into a power point but I'm a bit reluctant to use superglue (if one component broke it would be hard to replace/fix), but it would achieve definitely achieve what i'm looking for. I was hoping for basically this result but something a bit more stylish.

      In regards to the sub meter, its located in a different area of the house - I was hoping to install something the tenant could see and be able to track their own usage to avoid any surprises.

      Good tips though - if I could somehow hard wire one of those "dick smith/bunnings/kogan/ebay" power meters so that it cant be bypassed and I don't have to start gluing things together it would be perfect.

      • pjetson on 24/12/2020 - 13:10

        A power meter such as suggested by hothed usually only displays the amount of power currently being drawn by the device plugged into it. I haven't seen one than maintains a running total of power consumed, but it's possible that they are available.

        • Cusacka on 24/12/2020 - 13:15

          Ah yes, it needs to maintain a running total. Also it must not be able to be reset. If it is able to be reset then it defeats the purpose as every now and again it would "accidentally" be back at zero.

      • hothed on 24/12/2020 - 13:19
        +1

        Just so you start getting a feel for costs…

        Power meter $90 to $180
        https://www.sparkydirect.com.au/search-results?q=power%20met…

        Enclosure $26
        https://www.sparkydirect.com.au/c/236739/recessed-sub-board-…

        Cable / fixings $15

        Sparky labour 1 to 1.5 hours - $100 to 200

        Just keep in mind that it will measure kwh only, and it wont include the daily electricity supply charge or peak/off peak rates etc.

        Have a look on the unit to see what the input amps are, multiply by 240v to convert to Power(Watts), multiply Power (watts) by hours per day(watt hours), divide by 1000 for kilowatts, then multiply by days per year. Then finally by your kW cost by supplier. Avg in vic is 23.5c/kwh, NSW, 25.8c/kwh, SA 35.6c/kwh

        Do the same calucation for a "heavy" user, and a "normal" user, to determine what cost difference you're talking about is.

        • Cusacka on 24/12/2020 - 13:33

          Thanks this is useful. I was thinking about the $250-$350 mark and what you've mentioned seems to be around the $350 so I wasn't too far off.

          Using your calculations this is roughly equal to the electricity they would be using for the air conditioner over a year. Comparing my winter and summer power bills this also seems about right.

          So the break even of installing this would be about 1 year.

          • Seraphin7 on 24/12/2020 - 13:51
            +1

            @Cusacka: Why not just up the rent by $5/week ($260/year) and save yourself all this hassle and hoo ha?

            • Cusacka on 24/12/2020 - 15:22

              @Seraphin7: It's seems like a simple solution but the $350 is for normal annual usage and we've had bills multiple times that for just one quarter when the aircon has been left on 24/7. Also I would like to keep the rental price affordable to attract good tenants. This will create an incentive for them to use the aircon wisely where a rent increase won't provide any incentive.

              Actually it's interesting because we have another house and granny flat that we rent out separately and used to pay the electricity for both. Since installing separate meters the annual electricity cost has halved for $200 month to only $100 month, but of course zero for us.

              • Seraphin7 on 24/12/2020 - 15:30

                @Cusacka: Your place, your call, but consider the message you're giving … "great room to rent with air conditioner, electricity is included in the price … but I'm going to sting you extra for actually using the air conditioner".

                • Cusacka on 24/12/2020 - 15:32

                  @Seraphin7: I'm fine with that. Only have to pay for aircon elec, all other is free. The alternative almost everywhere else is to pay the whole lot.

                  • fozzie on 24/12/2020 - 17:37

                    @Cusacka: If people abuse Cusacka has the right to charge extra.

  • c64 on 24/12/2020 - 15:36
    -2

    are you sure you can legally charge for electricity?

  • fozzie on 24/12/2020 - 17:35
    -1

    That is so annoying op….. I would just do a calculation online and then speak to tenant and charge them extra.
    Have a look here http://airconacs.com.au/split-system-ac-running-cost/

  • Bisah1342 on 24/12/2020 - 19:10

    free powerpal?

  • Cusacka on 24/12/2020 - 19:20

    It looks like the way I proposed to do it will work so this can be closed. Thanks

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