Cost difference - air con fan v air con cooling?

[Pommygranite]

I have reverse cycle ducted and have been running the air con in Fan Mode rather than Air Con Mode at night (all night).

Any ideas of what the cost difference of running them is?

[StefanVXR8]

I would imagine it would be significant as you aren't performing any kind of cooling in that mode, so no compressor etc to run.

Been pleasantly surprised at how effective the ducted evaporative system is in our place, was a bit sceptical but we have run it for a couple of days in the last week and it's been really effective at removing the heat for the night, especially upstairs as our house is open plan and the heat rises up so the upstairs system has done a brilliant job of removing the hot air.

Stef

[Jader1973]

Don't know 100% but I found some stuff on the net comparing Evap with Reverse Cycle. Assuming running Reverse Cycle in fan only mode is similar to running Evap the number I found are:

Evap = 11c to 16c per hour
Reverse Cycle = 63 to 91 c per hour (whole home) or 36 to 54c for zoned.

So say a quarter of the cost to run Reverse Cycle as fan only, maybe less given Evap should include the cost of the water.

[Pommygranite]

Good responses cheers.

The 80c to 90c per hour figure looks right for us. A lot isn't it.

I think the fan matter will work for now but no good once the nights become humid and it starts sucking in hot air.

[caziques]

The outdoor unit will have the amount of power the unit uses shown on a label.

If it says for example 13 amps or 3 kW then it will use 3 kWs of energy every hour (60c in Oz?).

If it is a more sophisticated inverter unit, the compressor will slow down and use less energy when required, and hence be cheaper to run.

A fan itself will use relatively little power - perhaps 1kW overnight.