After a period of use (approximately 10-14 months, under normal conditions), beanbags filled with polystyrene granules need to be refilled with fresh granules, as the old ones settle over time. The granules inside your Pufrelax armchair will settle over time, meaning they will lose volume, and your beanbag will lose volume too! That is why we recommend purchasing polystyrene granules as a reserve to refill your beanbag and bring it to the right volume for optimal comfort!