sorry if this is a noob question, but the HVAC system in my home (3 story townhome 2000 sf) is distributing heat really unevenly throughout the house. The 3rd floor gets almost all of the heat and the living room and kitchen get nothing.
The distribution is so poor that if you increase the heat enough for the 2nd floor to be comfortable, the 3rd floor is unbearable.
if it is a single furnace system sometimes diverters are installed in the trunk lines that allow you to control the amount of flow to the different floors. I always tried to have these put in while duct work was in rough in. you may see a handle on the side of the main ducts that shows open to closed for air flow. usually near the furnace area.
Running the fan on continous will help some but it will cost $1 a day or close to it. Usually can cut that 10 degree differance between the upper and lower levels down to 4 degrees, depends on the ducting of course.