KW usage

[Tbird650]

The question came up recently about how much power my Fujitsu invertor actually uses. It's 4.8KW on heating but the thought was once it gets the room up to temperature does it begin to save electricity? So the thought was maybe the fan and the compressor can go into reduced power consumption modes. What can one expect? Thanks

[Deano240]

If it's inverter the compressor will ramp up and down pulling less amps

[install monkey]

put the indoor fan speed in auto- will slow down when it reaches setpoint

[Tbird650]

If it's inverter the compressor will ramp up and down pulling less amps

Thanks. Yes, I can hear the compressor ramping up/down... and that should equate to less amps as you say.

put the indoor fan speed in auto- will slow down when it reaches setpoint

Thanks for the thought. Yep, mine is set to that now and yes the fan speed varies I suppose dependent on the work load. Actually the fan speed can be right whacky in behavior, sometimes it starts racing for no apparent reason.

Are we talking my 4.8KW figure halving on light load or could it get down to say 1KW when it was doing almost no work, like effortlessly maintaining setpoint? I suppose I'm trying to understand in what situations I'm better off turning the thing off altogether.
Thanks!

[mikeref]

A/c's are there to Cool or Heat just to satisfy the indoor temperature sensor via a resistance value. Air-conditioners have no idea of their current power consumption.

[still learning]

I think. The sales blurb. Used to say in heating one kw spent gave. Two kw free.
As it is a very. Efficent way of heating .
But in cooling. It was one kw spent one kw used .
i have a multi split. One wallmount in lounge and one in main bedroom, only heat. The lounge in winter as. We have heat recovery too, a all electric house ,no gas , wife home all day
so she want to be toasted,and only £400 ish. For our worst quater of electricity.
the walls are rammed with insulation too.
best thing we ever did was aircon the home

[Tbird650]

Somewhere I have a digital power usage meter. It's a Chinese made item that fits over the feed wire and records current use. If I fit this to the heat pump wiring it will tell the full story... no bull, hype or sales blurb.
It would be interesting. Hoping to do it soon. Now where is that thing...

[Magoo]

Tech Rentals hire out accurate Kwhr certified check meters. You will have to compare indoor and out door temps as well as power consumed for an effective efficiency performance.
The latest model blurb for heat pumps is a 4:1 average COP on heating.
Let us know how you go with results.

[Goober]

I've always had an interest in this sort of discussion. Always, sort of, maybe, when I get round to it, which will probably be never, wanted to carry out an exercise on this. Possibly get 2 exact same rooms and put a fixed speed AC in one and an inverter in the other, both same nominal kW rating, wire them up for monitoring and see what they produce, draw amps etc.

But as I say, when I get round to it.....

[Tbird650]

Turns out my meter doesn't work so I can't monitor it at this time...