"Is there some way to connect one of the aircon units to the Quattro so it can run off the batteries/solar panels?
Yes the Quattro has 2 x AC outputs:
One is live only when Shore power or generator is on.Call this "Output A"
The 2nd is also feed from the inverter as well as shore power and generator call this "Output B".
"Output A" Should be connected to the Air Con that is to only run on shore/generator power.
"Output B". Should be feed into the boats main AC system. This way you can run everything else from the inverter/shore power/generator as required.
You say you also want to run an existing 2kW inverter (What is it ? Why is the 5kW not enough?)
Interconnection between to sources of Inverter AC could be very problematic, if not interconnected and controlled same style units eg: Victrons are made to link together to give more kW's.
"Where did you fit your 5Kw Quattro, as we are struggling to find a space for it?"
Is your 450 an L or an F?
Places I have seen them mounted under bed
Clear Horizons mounted it in Electrical
cabinet under TV after removing now redundant AC switching panel and relocating still required existing equipment
On an L450 "S" I believe there is space up in the helm
seat area but Dave will know more and hopefully chip in.
"Can you recommend somewhere in Southern Spain or Gibraltar that would be able to install the system for us?"
Sorry no idea on that one, from the other side of the world.
Some other thoughts on installation. When installing panels and MPPT
controllers you will require to put in circuit breakers. Make these easily accessible. I placed under the bed
and there are times when getting at them to turn systems on and off would be so much easier if the bed did not require stripping down to get to them.
Monitoring and switching panels are better mounted on the wall just aft of the Owners side door at eye level. Way easier to stand and program or check on charging
levels than sitting on the stairs with electrical
door open and blocking said stairs.
If not to late go with Victron Colour control, Battery Monitor
and Victron MPPTs as these will all talk to the Inverter and make for a very good combined system.
I have Master Volt Battery
monitoring, Victron Inverter and Outback MPPT
all work well but you need to read each to see what is charging
and what is using power and do some simple math to work it out. Whats what.
The Victron Colour Controller shows in graphical display, what power is being produced and what power is being consumed and what is going into the batteries all at a single glance.
2,700 Watts is not a lot, it's almost perfect (you can never have to much power), combined with 1500 amp/hours of AGM's or similar capacity batteries and you will be a happy camper.
Just my thoughts there is no right or wrong whatever works for you.