One person told me I need to change my Registers on the first floor that are in the ceiling because the house was set up for air not heat. They say the Registers I have keep the cold air going a crossed ceiling because cold air falls. Now with the heat pump they say you need a Register to blow hot air to the floor because hot air raises.They say if you don't do this it will be cold where you sat and warm at the ceiling. Does anyone know what Registers I need For the heat pump/A/C ?? Do they make one Register that does both or doing you have to switch it out?
There is something to what you've heard, but it's not like you will get no heating with the current system. It may not be ideal, but it'll work. Unless you live in the Southern hemisphere, you should already know if it's going to be an issue or not. Most registers do not blow flat across the ceiling but at an outwards, downwards angle.
You could change out the registers for those with a more straight down configuration, or even a simple grille with no directional fins. But also consider what happens in the Summer. Air con blowing straight down is not good for the same reason it's good for heating. You should select the dispersion pattern for the most critical condition.
In primarily hot climates, air con takes priority, do what's best for that. It's the other way around for primarily cold climates. Or obtain adjustable registers so you can direct the flow as needed.