When air leaks around windows, energy is wasted. Energy is also transferredthrough the centers, edges, and frames of windows. Eliminating or reducingthese paths of heat flow can greatly improve the energy efficiency of windowsand, ultimately, of homes. Before applying new caulk, old caulk or paint residue remaining around awindow should be removed using a putty knife, stiff brush, or special solvent. After old caulk is removed, new caulk can then be applied to all joints in thewindow frame and the joint between the frame and the wall.
Low humidity is important during application toprevent cracks from swelling with moisture.
Warm temperatures are alsonecessary so the caulk will set properly and adhere to the surface. Weatherstripping is a narrow piece of metal, vinyl, rubber, felt, or foam thatseals the contact area between the fixed and movable sections of a windowjoint. It should be applied between the sash and the frame, but should notinterfere with the operation of the window. The type and quality of the window frame usually affect a window's airinfiltration and heat loss characteristics. When properly installed, fixed-pane windows are airtight and inexpensive andcan be custom designed for a wide variety of applications.