(04-25-2020, 07:33 AM)blackhat Wrote: Roly, this is a plan for replacement, not a done deal. Several factors will come into play. Most critical will be the airflow I can get from the system. With an ECM motor on the main blower, the fan speeds are programmed with limited adjustment available. I will only have the systems continuous circulation airflow available, I won’t be able to access heating speeds. Supposition is that I will be able to run the heat pump and meet the house’s  needs to approximately 40 F. That is still a good chunk of the year I can take advantage of. My heat pump would be sized to the cooling load of the house which is lower than it would be in more southerly zones. There is some noise about increasing fan access or new models more flexible in the future but I haven’t chosen specific equipment yet.