I just bought my first home and have a ton of questions. The first
being how do I know if I need a dehumidifier? The previous owner had
one in the basement. The basement is dry but does have a drain in the
floor which goes to the city system. Some days, the air in the
basement is a little damp. The basement is 3/4 finished (of course
with nasty 1950's panelling).

If I do use one, do I need to use it year round? Also, what size
would I need, basement is about 700-750 Sq. Feet.