Recommendations for a good HVAC system for ADU?

[Bruce P.]

Hi,

My friend is building an approx 610 sq foot ADU in southern california. It looks like the new standard for air conditioners is freon free.

Any recommendations on a good A/C (as well as heating system)? For an A/C, it looks like I need about 14,000 BTUs per hour for a 610 sq foot ADU if my Internet research is to be believed.