Joe wrote:

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.



"The basement is dry", but "Some days, the air in the basement is a little damp"
Decent dehumidifiers have a humidity detector that turns the dehumidifier on and off as needed. They also can be adjusted for the amount of dehumidification wanted. The dehumidifier would only be cycling on and off on those days when the basement is damp. My basement (~900 sqft) 25 pint Westinghouse dehumidifier hardly ever goes on in the winter, since there is less humidity in the ambient air. Since your basement is somewhat finished, I would spend the ~$130 or so, to keep the paneling, stored items, furniture, and other materials, from absorbing all that damp air.