Split Air con

[montymint]

£600 is 600 at the end of the day. Not sure any difference between brands will make up for that.

How big are the rooms you are putting these in? They seem rather large for a typical U.K. bedroom/office room.

The heat loss/gain of my entire 4 bed detached house at a temperature difference of 23c is only 5.5kw.

That doesn’t include any solar gain shouldn’t be massive unless the room is covered in rubbish glass. Practically in the summer, the most you’ll see is a temperature difference of 10 (30 outside vs 20 inside).

That said, there may not be a suitable multi split unit which is smaller than 5kw as that’s a pretty small unit in reality.

Just two standard double bedrooms, however one serves and mine and the wifes office space, which with two pcs, laptops and ultrawides has been getting very toasty, especially as the room is South>south East facing

 

[montymint]

I did get a quote for a single, larger unit for that office, which may be strong enough to keep upstairs cool on it's own:

as I have cats, my internal doors stay open

 

[b0rn2sk8]

You probably won’t need to run them above low for the two rooms once you get into it - check the unit quoted is an has an inverter compressor, they can modulate their outputs.

Once you get them, the way to get the best out of them is long cycle times. It takes a shed load of energy to start up the compressor but once it’s running it will consume a modest amount of electricity.

What you don’t want is for the unit be on too high, cool the room rapidly, go past the set temperature and shut down. 20 mins later it starts up again, rinse and repeat. When people complain about energy consumption of AC, this is how they are normally using them.

Most AC tie their compressor outputs to the fan speed so sticking it on low fan speed for long periods of time is the way forward, you just want to keep it running continuously to prevent compressor shutdowns.

 

[montymint]

You probably won’t need to run them above low for the two rooms once you get into it - check the unit quoted is an has an inverter compressor, they can modulate their outputs.

Once you get them, the way to get the best out of them is long cycle times. It takes a shed load of energy to start up the compressor but once it’s running it will consume a modest amount of electricity.

What you don’t want is for the unit be on too high, cool the room rapidly, go past the set temperature and shut down. 20 mins later it starts up again, rinse and repeat. When people complain about energy consumption of AC, this is how they are normally using them.

Most AC tie their compressor outputs to the fan speed so sticking it on low fan speed for long periods of time is the way forward, you just want to keep it running continuously to prevent compressor shutdowns.

Yeah, that's ideally how I want to run them. Basically just maintain an ambient temperature between the rooms throughout the day, and hoping the solar (once installed) will cover the running costs. They're not being brought in to cool / heat quickly in a pinch - I spend too long in the office (WFH) to do that.