Hello. I am a new member here.

I live in a 5700 sq ft home (including the basement which is about 2200 sq ft) right outside of Atlanta, Georgia. The house has three HVAC systems - one for each floor. A 2 ton system serves the upstairs which is about 1400 sq ft, a 3.5 ton for the main level which is about 2200 sq ft, and a 1.5 ton for the finished basement. The main level and upstairs systems are fine, nothing wrong with them. One of the rooms in the basement never gets warm in the winter, and that's the game room where my teenagers are hanging out in all the time. The basement system is a Trane XR11 heat pump which was installed back in late 2003. Three of the rooms in the basement have 7 foot ceilings and the main theater room has an 8 inch supply duct going in to it from the air handler. There's only two returns in the whole basement, one 10 inch return in the theater room, and one 6 inch return in the man cave. The thermostat is located in the theater room. The man cave has a 6 inch supply going into there. There's also an unfinished workshop which has a 6 inch supply and also an unfinished bathroom that has a 4 inch supply. Both of those rooms will be finished in the future. One finished storage room has a 6 inch supply. There's a 6 inch supply going in to the game room. Air flow is very week in there, and my teenagers are always complaining that it is cold in there all the time in the winter when the heat's on. The other rooms get OK heating in them.

My question is, what can help the game room get good heating? What changes can happen in the future to improve the heating in there? What would you recommend? Sorry about the long post.