not seeing any radiator piping - was air to air heat pump ever on your horizon ? (recently commented in a couple of threads about it's UK heat+cooling application )
LOL - 'U' horizontal cross section, traversing 3 adjacent walls, or pay for a better AI license - aren't no doors risky for any clothing moth liability.
No radiators. We have ducted hot/cold air in the ceiling cavity ran from a Mitsubishi heatpump. Main goal being that it stops guests ramping the AC when visiting and destroying our battery stores, along with no ugly boxes everywhere.
The stupid thing is that the above was from a "home design" platform which had a subscription model. I was just using the free trial. Not something that makes me want to consider a membership. Currently utilising my works co-pilot app.


