Heating a house

[crc_error]

Just got a question, we have a 5 star ducted heating system which heats our 20sq house.

My question is would it be cheaper to use a Fujitsu to heat only the living are which is been used, or heat the whole house with gas ducted heating?

Does anyone know where I can find out the running cost of these items?

the Fujitsu is running on electricity, and the ducted is gas.. isn't electicity usually more expensive to use than gas?

 

[HiEquity]

The Fujitsu is a heat pump (aka "reverse cycle air conditioner"). It takes heat from outside and pumps it inside, like a fridge for your house when cooling or in reverse for heating. It is actually about 400% efficient as it is just using electricity for moving heat around that already exists instead of creating new heat.

Normal resistive heating (ie bar radiator or oil radiator) is just electricity turned into heat so isn't very efficient and yes electricity is more expensive than gas when used this way.

When I do the numbers in Perth, the Fujitsu and the gas work out about equal for cost and efficiency. Conversion from gas to electricity is around 25% efficient by the time it gets to your home x 400% in the unit and you are back on par with gas again.

The clincher for me is the ability to run the Fujitsu in cooling mode, which is a bit difficult with gas! But that is a Perth decision and in Perth also, evaporative cooling is more efficient again than a Fujitsu (but doesn't work for heating of course!) as you are just running a fan really.

Hope this helps.