My heat pump was sold as having “700 levels” (that’s 30-100% in 0.1% increments), but the Nexia software shows unit % and also Level 1 or Level 2. Who knows if it’s actually using the fine grain control I paid a lot of money for?
My first thermostat also died in the first year when the power went out. What happens in 10 years when it’s no longer made? I have to dump the whole system and start again?
Also whole features are poorly implemented - Quiet Mode limits speed at night, but not until after startup (or, I think when defrosting)
I’m a bit unhappy with Trane/Nexia at the moment and would absolutely not recommend
The availability of multi-speed or variable speed compressor (inverter drive) is extremely limited in the residential market space outside of anything proprietary because there isn't enough cost flexibility. It doesn't help that American manufacturers are at least 20 years behind the Japanese and Korean makers on developing these.
It generally doesn't make sense for the manufacturers that have the tech to make open hardware systems for this market segment when you're only talking about $1000/ton for residential hardware. The lock in is more valuable than the initial sale is my guess.
I think one could likely home brew an open-hardware variable speed system by retrofitting a standard three phase compressor and variable frequency drive (see Jeremy Fielding's youtube channel—linked below) to their residential unit but it is hard to find a small enough three phase compressor and wouldn't probably be mass marketable because even single stage units are often good enough for most residential applications.
Future building code adoption will probably have an influence on this particularly in the areas where ventilation requirements are tightened.
My first thermostat also died in the first year when the power went out. What happens in 10 years when it’s no longer made? I have to dump the whole system and start again?
Also whole features are poorly implemented - Quiet Mode limits speed at night, but not until after startup (or, I think when defrosting)
I’m a bit unhappy with Trane/Nexia at the moment and would absolutely not recommend