They can also be major sources of heat lossin the winter and heat gain in the summer. However, when properly selected andinstalled, windows can help minimize a home's heating, cooling, and lightingcosts. 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.