What is probably happening is the cold air produced by the floor vents is not able to cool the air at the top of the vaulted ceiling. This is because cold air is denser than warm air. You are going to have to install supply vents near the top of the vaulted ceiling. You should also install a return at the top so warm air can be pulled out of the space. The supply and exhaust vents should be placed on opposite sides of the room.

A fan can help mix the warm and cool air masses. I would think the fan blowing air on you would make it feel cooler due to the wind chill affect. In the winter you can reverse the fan so that you won't feel cool air blowing on you.

The other strategy is to lower the heat load of the room. How much insulation is installed in the attic above the vaulted ceiling? Depending where you live you want at least R30, and ideally at least R40 insulation value. Closing blinds when the sun is out will help. You could also apply a reflective film to the window glass to help reflect the sun's rays. You may like that look instead of closing blinds and drapes.

@mike_home there is insulation throughout the entire vault. Not sure which type. We do not have shades yet and plan on buying 3% solar shades . So you are saying we will benefit more with the supply being at the top then where they are on the floor right now.

If you could supply cold air near the top, then it will naturally "fall down" towards the fall. This should create some convection air currents.

If you are going to buy new HVAC equipment then find someone who will do a load calculation. Vaulted ceiling are very nice but unfortunately they present heating and cooling challenges.

"but unfortunately they present heating and cooling challenges."

That is true so make certain anyone you hire understand's how to address said challenges.

Vaulted ceilings tend to trap heat at the top, but placing a return vent is typically not pleasing aesthetically... same thing with supply vents.

So you have your work cut out for you.

A lot of people do not like to be able to see beyond the grill. Due to the angle of the vaulted ceiling this is very challenging.

Vaulted ceilings are a statement... that statement gets clouded is about the best way I can describe it.

Another option would be to place a ceiling fan in the center of this room and reverse the fan to blow upwards. This will pull air off the floor and push air up to the vaulted ceiling which creates a cascade effect. Depending on the room size you would want a ceiling fan with a wide wing span so you don't have to run it on high speed for it move a generous amount of air.

The idea is to just keep hot air from getting trapped in the vault of the ceiling and pull up the cooler air off the floor. This is aesthetically pleasing as well.