Why down items lose their insulating properties when they get dirty and wet...
Down filled items are used to provide lightweight insulation to keep you warm. The structure of down allows air to be trapped between its filaments and warmed by body heat to provide insulation for the user.
Through use, dirt and body oils build up on down items. This effects both the fabric and the down fill. Dirt attracts water; if the fabric absorbs water, rain and condensation can easily transfer into the down. If down gets wet it clumps together. This causes it to lose loft and insulation as it can’t trap air effectively. When wet, down loses all of its insulating properties, as water conducts heat away from the body up to 25 times faster than air. It will also gain weight and its breathability will be significantly reduced; leaving you feeling cold, wet and uncomfortable.
Down filled items are most likely to get sweaty and wet inside when used in damp or wet conditions. Therefore it is important to stop down filled gear from getting wet by maintaining Durable Water Repellency (DWR). The outer fabric of your down filled item, as well as the down inside, must be maintained to ensure comfort. Nikwax Down Wash Direct will revitalize the insulation and restore DWR.
