Hugh Wong wrote:
I would like to improve the air flow to the master bedroom in my
house. Presently, the air is not as cool as it should be. It's about
5 degrees warmer than the other rooms. Physically, this bedroom is
the farthest distance from the main unit which is a Day and Night, 5
ton A/C. The house is 1700 sq ft. All the other rooms have sufficient
flow and cooling. There are about 7 vents throughout the house. I
tried temporarily installing a stove exhaust fan just outside the air
duct but that didn't seem to help the air flow or the cooling. Any
ideas on how to rectify this problem?

Put in a window unit. You can get a new one for less than $150.

I did that and cut my cooling bills by 2/3rds, saving the cost of the unit
in two months.

That was three years ago.

I'm gonna buy a mongoose with the money I saved. Or maybe something else.