We finalized the design for the heating and cooling system today.
Heating will be supplied by a 30Kw Baxi Condensing Boiler with 16 panels throughout the house. The panels, and the AC ducting are marked in the drawings below.
The refrigerated cooling / AC will be supplied by a Toshiba mini-split system, with 5 indoor units, and a compressor outdoors. See the below Toshiba schematic for more detail
Cummins Contracting will be doing the all the work for both the heating and cooling.
The things that surprised me most was (a) the overall expense of the cooling system (2x the cost of the heating system), and (b) the oversizing of the cooling system.
My own heat load calcuations show that the 5.6kw units could be 3.5kw (and still 50% oversized) and the 8kw bedroom could be 5.6kw. The cooling contractor however tells me that it will barely make a difference in cost to go with smaller units, and if it gets hot, the bigger units will cool down the house faster after the AC has been turned off for a while.The units are "inverters", and only run at the load they need to run at.
I'm also looking to integrate all this into the home automation system. We're using an HAI Omnipro security/automation system. We'll be pairing the boiler with an HAI omnistat2. Controlling the cooling system is more complicated, and I'm looking into using the Coolmaster 3000T to achieve this.