My master bedroom is consistently 8+ degrees warmer than the rest of my house. The thermostat is in the hallway, which is on the other side of the side, has normal ceilings, and is in the dark...The master has huge vaulted ceilings, two floor to ceiling windows and to get it to 75 in there the rest of the house has to be 68.

Not efficient.

The windows are new. That helped. But other than the new windows and black out shades. How can I cool the room down?

Open to all thoughts here. Would not want to go straight neck and install a window unit... but I know that might be the cheapest and most effective option.

What else might I look into?

Solar shades or tint the windows?

Have an AC company balance your system.

This seems to be the best idea. You may need another vent in that room.

Mitsubishi makes self contained, free standing ac units.

Get a remote thermostat and put it in your room. Then partially close off the vents on the other side of the house to restrict the air there. Also keep ceiling fans on 24/7 to circulate air throughout the house.

One thing I enjoyed about our San Antonio house was that it had 2 HVAC units. One for the 2nd floor that was all bedrooms and one for the first floor. Might have cost more initially, but it cost less per month to keep the house the way we liked it. Plus when one of the compressor fan motors burned out we had a section of the house that was still cool until the unit could be repaired.

There are ways to balance the air flow like stated previously. Our current house has a good balance during most of the year, but middle of the summer the only thing that keeps the southwest corner room as cool as the rest of the house is leaving the ceiling fan on and lowering the Roman Shades. The new portable room AC units would probably be the cheapest route up front, but will add to your energy cost.

Of course, you could always make one of these.

Probably the duct work going to your bedroom is crimped and not allowing the air to flow through unrestricted.

I use a oscillating floor fan at night. $17 at Walmart.

I'm thinking of getting Yeti to insulate and do the walls on my next house. Throw a few ice cubes in the bath tub and stay cold all summer.

That just reminded me of the one bedroom in our San Antonio house that stayed warm. Went up into the attic and they had the strap holding the flexible duct not only so tight that it was only allowing half the air flow to that room, but it was strapped up to the bottom of the roof. We cut the strap so the the tube was laying across the insulation (on a couple 2x4's to keep it elevated a bit) and the room was then like the rest.

This. You need a greater amount of air blowing into the bedroom. This will help balance.

I have black out shades as far as that part goes. And the ducting looks fine. Its just the last run on the line. The farthest from the unit.

I think to see a big difference, i might have to go redneck and get a little window unit. But I hate that then you have to use those plastic panels to close off the windows. With the airport being so close, the noise is a bear. Part of the reason I replaced all the windows was to cut down on that rumble.

Keep the ideas coming. I am going to look into all of them.

How old is the house and what kind of duct work do you have rigid or flex? Mine is flex and has dampers installed on a few of the trunks to different rooms so that I can control the air flow to each room. Yours may not be set correctly. Do you have powered turbines in the attic? Is the attic ventilated well? There are tons of videos on youtube about this topic. Is the Master bedroom on the west side or east? Evening sun is a killer. If you think heat is being transferred through the windows, they make insulated drapes that could help. I dunno, just some ideas.