Will a dehumidifier help with my sinusitis?

NO: A dehumidifier generally is not a good idea to help with sinusitis... It will dry your nasal secretions.. Not a good thing. However, if you have a mold issue (and allergy) related to a damp basement... Then a de-humidifier may help.

Might not: Sinusitis is in part excess secretion to rid the nasal passages of noxious material. A dehumidifier might help by lessening the mold count but it might also harm things by drying out the sinuses and making them more irritated. You must evaluate your particular circumstances.