We've recently moved into a bungalow. Ripped out old fitted wardrobes in main bedroom which were on an outside wall and noticed damp on the wall. Went in the loft and the roof felt above the bedroom was soaking with condensation. We bought a de-humidifier and put it in the bedroom. I was staggered how much water it collected. Same in all the other rooms. Ventilation seems to be the key to dealing with condensation. January and February are the worse months. I put some lift vents in the roofing felt overlaps, and we keep a small window slightly open in the bedroom and bathroom. The difference now is remarkable. No more wet roofing felt or damp walls. Still use the de-humidifier though and I think they are worth every penny. I would urge you to ventilate your home though as you do produce a lot if condensation when sleeping and drying clothes on radiators. Sorry about the long post but in answer to @RedM question, then yes I would say definitely get one.