Using Loft Circuit for Split AC In Bedroom

[HenryGregory]

I’d appreciate some advice on this.
I’m looking to install a split-system air conditioner in my front bedroom. Accessing the power sockets in the bedroom would be difficult, so I was wondering whether the installer could instead use the loft circuit for power.


The loft has a dedicated 16A MCB on the consumer unit. Currently, the loft powers the following:

• A Vent-Axia MVHR unit (120w/0.12kWh)
• A 12 volt network switch
• A powerline adapter connected to a CCTV NVR
• A TV aerial booster

The total load on this circuit is currently light.
Would this circuit be suitable to supply a typical domestic split-system AC unit?
I am looking at a small units such as the Mitsubishi Heavy IndustriesSRC35ZSP-W, which has a rated input of 1.65kW and a cooling capacity of 3.2kW and a heating capacity of 3.6kW.

I’ve attached a photo showing the powerpoint in the loft. The fused spur in the image supplies the MVHR. The bedroom is just below where the fused spur currently is.

Thanks in advance for your help.

 

[morqthana]

Have you spoken to Vent-Axia to see if there are any cooling options for your system?

 

[HenryGregory]

Have you spoken to Vent-Axia to see if there are any cooling options for your system?

At the time I moved in, yes but you would have to get a third party option and it wouldn't reduce the temp by that much. It seemed it would be more cost effective to put in a proper AC unit which can also heat.

 

[phatboy]

At the time I moved in, yes but you would have to get a third party option and it wouldn't reduce the temp by that much. It seemed it would be more cost effective to put in a proper AC unit which can also heat.

MHRV ducting is nowhere near large enough to be able to provide cooled air, so yes an air-con unit would be required for what you want.

With a split system, the outdoor unit is going to use the majority of the power, the unit inside the bedroom is going to use very little (Except possibly in heating mode, if this is a large convector heater instead of a heating and cooling heat pump. So where you power the outdoor unit from is the important bit, the part in the bedroom would be fine in a 16amp circuit

 

[HenryGregory]

MHRV ducting is nowhere near large enough to be able to provide cooled air, so yes an air-con unit would be required for what you want.

With a split system, the outdoor unit is going to use the majority of the power, the unit inside the bedroom is going to use very little (Except possibly in heating mode, if this is a large convector heater instead of a heating and cooling heat pump. So where you power the outdoor unit from is the important bit, the part in the bedroom would be fine in a 16amp circuit

Thanks, so what I am thinking is run both the outside and the inside from the loft circuit seeing as it is 16a, cable thickness is the same as the 32a circuits and it has minimal load on it currently and won't be having anything else in the future unless someone were to convert the loft.

 

[morqthana]

Let us know how you get on - I'm thinking of running cable(s) into the loft to use for air-con, maybe, in the future.

It's a real double-edged sword though - adding to global heating to counter the effects of global heating. But sacrifices of no more ICE cars, no more flying, no more imported asparagus, no more (or a lot less) meat, in order to drive down carbon emissions are one thing - dying in heatwaves is quite another.

 

[morqthana]

MHRV ducting is nowhere near large enough to be able to provide cooled air

Is it though?

What if the air being pumped into the ducting had been cooled to 5°C?

OK - I'm not saying that air that cold is practicable, but is the problem really the ducting? If, all the time, the air being distributed around the house was at, say, 15-20°, then in conjunction with window shutters or closed curtains, would that not achieve a useful lowering of the temperature indoors, even if not to the extent of "real" A/C?