[varyouga]

In most climates ductwork is designed for AC mode which if properly engineered is more than enough airflow to supply heat with the same fan/duct. Even at 92F supply (20 degree delta above 72F room temp)

Of course if you slap a heatpump on a duct system that was already undersized for AC, it will definitely not be adequate with 92F supply.

[know.your.why]

Even at 92F supply (20 degree delta above 72F room temp)

My body temp is 98.6. That 92 degree air coming out of my vent feels lukewarm at best. A heater is supposed to feel heat. Heater-heat-heater. See how that works? 92degree air coming out of a vent when its 25-35 outside aint gonna do diddly.