I'm finishing my basement and the main room will be the intire length of the house. (apporox 50-60 ft). There are two heating vents directly out of the main heating duct in the ceiling of the basement. Each one is about 10 feet from each end wall.

Will one cold air return near the floor in the middle of that room be sufficient or do I need more? If so, where should they be placed? Should I just use a ceiling fan to get the heat pushed down into the room or is there a better way? Is it better to have the heating vents in the ceiling or near the floor?

Any advice would be appreciated. I would just like to be able to heat the large room the best way I can.

Thanks,

Basements usually take more heating than cooling. I would go with the one vent at the floor in the middle. I hope you started with sealing the basement good. Depending on how old it is, you may need to run a bead of caulk between the foundation and plate, the plate and the band joist, and the band joist and the sub floor above. If you fur out, insulate between the foundation and drywall. A tight, insulated basement shouldn't need that much heat. My unheated crawl space is good enough that it stays about 60 degrees in the winter. That makes my hardwood floor in the house nice and warm.

The only thing I'd add is to have as close to equal square inches of return opening as you do of vent opening.

Thanks for the answers. It leads me to another question. My house is a split level and is 3 years old. The basement is all insulated and there are no moisture problems. The main room in question is 15' X 43'. The stairway coming down is in the middle of that room. The one cold air return I planned on putting in would be right next to the stairway. We are not putting a door on that opening so there will always be free flow from downstairs to upstairs or vice versa. My question now is would a cold air return even be necessary if the room is open to the stairway leading up? Wouldn't the air just go that way instead of in the return anyway or would you think a cold air return running in with the other ones of the house still be necessary?
Thanks

Two opposite thoughts. The duct is already there, may as well put the vent in. Or you could try it without the vent and add one to the existing duct later if you seem to need it.