Well don't hold your breath! Just like home solar heating ,the technology is out there, yet the public just isn't buying it! 20 year ago I offered solar/woodstove /gas hydronic heating systems in my business, I sold/installed a few of them but mostly I got a lot of hot air from people who like the concept but refused to put their money where their mouths where! I know they work I installed one in my home, hydronic being the most efficient medium to transfer heat from the sun to the home but people where more concerned about the initial cost input not the return!
Besides HVAC was cheap although expensive to run and unhealthy and made cooling the home cheaper and easier despite the lack of efficiency!
People who build new homes look at the $2000.00 HVAC system and compare it to the $10,000,00 or more Solar/wood stove/gas hydronic systems and choose the former consistently! Its a shame I know I was very disappointed in this reality!