Gas Ducted or Daiken Inverter?

Discussion in 'Renovation & Home Improvement' started by albanga, 1st Jun, 2016.

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  1. albanga

    albanga Well-Known Member

    19th Jun, 2015
    Hi All,

    Wanting some advice.
    I am finalising my build contract and am unsure what heating/cooling option to go.
    My current quote includes split systems but for various reasons I want to steer away from these (OK my wife thinks there ugly, lets move on :p)

    House is around 26sq double story.

    My builder's heating/cooling guy has given me two options:
    Ducted with Add On: Braemar TQM5X30 5 Star = $3,400 additional
    Daikin Inverter FDYQN160LAV1/RZQ160LV1 16kW (Single Phase) unit with the same zoning schedule (Common + 2 Zones) = $4,000 additional

    The price difference on installation is not drastic, I am probably more concerned with the costs to run it so i asked and got the following response:

    Ducted Reverse Cycle

    Assuming electricity tariff of 27.7 cents/kWh

    Daikin FDYQN160LAV1 Cooling Input = 4.97 kW

    Heating Input = 4.83 kW

    Cooling in Summer = 27.7 * 4.97 = 137.67 cents/h

    Heating in Winter = 27.7 * 4.83 = 133.79 cents/h

    Gas Ducted

    Assuming electricity tariff of 27.7 cents/kWh and a gas tariff of 1.50 cents/MJ

    Braemar TQM5X30 Gas Consumption Rate = 122 MJ/h

    Lennox LCS-18C-12X Power Input = 5.45 kW

    Cooling in Summer = 27.7 * 5.45 = 150.97 cents/h

    Heating in Winter = 1.50 * 122 = 183.00 cents/ h

    However you need to keep in mind that these figures do not take into account the power input to the heater’s fan which will be operating also.

    It is evident from these quick calculations that reverse cycle does offer lower running costs, in both heating and cooling modes.


    I was under the impression that gas would be cheaper to run? This obviously says different.

    I would appreciate any feedback. Ideally if i could save $600 on install and its cheaper to run then it is a no brainer :)

    Thanks in advance!