The chimney effect occurs when warm interior air rises and escapes over improperly installed window treatments. This creates a continuous cycle of heat loss that negates the insulation benefits of natural textiles.
Warm air naturally rises due to its lower density. When window treatments don't create a complete seal, this warm air flows over the top of the material, creating a draft that pulls cooler air from below, establishing a convection current.
This effect can reduce the effective R-value of insulation materials by up to 40% if not properly addressed. The key to eliminating this problem lies in creating a complete thermal seal around the window perimeter.
Proper measurement and installation techniques prevent air movement over, under, and around window treatments. This requires attention to detail in both material selection and installation method.