Furnace not blowing heat/air evenly

[Jay Y.]

So I have two rental houses built in the early 80's.  The first one I bought about a year and a half ago.  Problem is the upstairs gets super hot while the downstairs stays colder in the winter.  I had 2 different hvac companies come out and was told there's nothing they can do about it.  The furnace is in a hallway closet upstairs and my property manager said usually the vents closest to the furnace will get the most air.

I just acquired another house also built in the early 80's and same thing, upstairs gets all the heat while downstairs is a bit cooler.  This time the furnace is in the attic.  

I assume both the hvac and my property manager are correct?  Is there an actual reasonable fix to this or do I have to install the fancy heat sensing flaps that will close off air flow going to the bedrooms???

Thanks so much!

[Account Closed]

Follow the trunk ducts coming out of the furnace, you will see little damper handles. I prefer to adjust these rather than room vents so tenants are less likely to fool with them. This might be what @Bob H. is referring to but wanted to add some clarity. Good luck.