I am working on a design for a self build house, aiming for 8 or 9 NatHERS rating. Given the design and location I have a peak heat requirement of 3kW, and maximum daily heating of 24kWhrs excluding solar gains.
When I add the solar gains, I believe I could provide the bulk of heat from a shared solar collector (sharing domestic hot water and heating, with electric boost for exceptional cases). 60<=>90 evacuated tubes with inclination optimized for July to minimize overheat in Summer. Looking at using a conventional >400L residential hot water tank with electric boost. And 3x in slab hydronic loops for delivering heat.
So here is my question, how do you share a conventional residential boiler?
- Are open systems (sharing heating and domestic hot water circuits) non compliant in Australia? I have seen these designs on some international sites.
- If so I need to separate the heating circuit by insert a heat exchanger and making it a closed loop. Does anyone have recommendations for local suppliers of necessary components? (plate heat exchanger or boiler with internal heat exchanger / expansion tank system for the closed loop)