I generally like the product as described, but definitely there are tricky challenges for you, and no-product launch at HN is perhaps a bit premature. (You can't do a launch like this on HN, you need to hype it up in the media and then to it a-la Tesla).

As specifically for the product:

All-electric is no-go in many locations. I live in the (outside) Seattle suburb, electricity goes out few times in the winter. In this case I can still heat from the gas running controls from the generator. I.e. back-up furnace is an important add-on.

It's unclear what is your production strategy: if you repackage existing devices with better software and integrations, then it's a viable option since repairs can be reasonably done (i.e. I had control board on the AC unit replaced in a day and failed water heater replaced in 3 days). If you produce new hardware, then it's hard to justify: when it fails in the winter, what exactly is the repair plan?

In addition to that ducted heat pump with smart controls is not exactly a new concept, I can buy one right now. It looks like yours is going to be integrated with better sensors, humidifier and ERV? Are they part of the system? Are they separate install?