Because warm air naturally rises the chimney flue is a major source of heat loss the chimney flue balloon effectively provides a barrier to prevent cold draughts and heat loss saving you money on fuel bills and naturally making the living area warmer more comfortable and with less draughty it is made to be quick to install yet allows removal for reuse again and again designed for people who like to light a fire at the weekend its completely safe if heated shrivels up and also stops de