In Melbourne’s climate where piped methane costs 1/3 per kWh that of electricity, but heat pumps are 300-500% efficient and you remove the duct loss, for most people their heating bill drops by 2/3. Add solar self consumption and you are way ahead.

My limited understanding of the defrost cycle is that it’s most a problem around 0c? If it’s a colder or warmer it doesn’t get triggered as often?