I have very old and very drafty windows! We do have storm windows but I am wondering if there is anything else I can do to tighten up the wood double-hung part that they cover to reduce drafts? I don’t want to go through the hassles and expense of tearing out my siding to install new ones?
Drafty windows can have a big impact on your energy costs as well as your comfort. There are a number of things you can try to improve the situation short of replacing them. First, check the fit. Many times, windows will warp or twist; or the wall will shift and result in them closing unevenly, leaving space where air can sneak through. To check yours, close them very carefully and look at the alignment where the base of the window strikes the window sill, as well as where the two windows styles (top and bottom frames of each window) line up. If you see gaps, the window would be trimmed to improvement the fit, or you can deal with it by adding additional weather-stripping.
Speaking of which, that would be the next step. Check the gaps around the window to be sure that the weather-stripping seal is intact. If not, you may need to replace it. There are many, many types of weather stripping available. The type that works best for your situation is probably going to depend on which type fits the application the best. I have had the best luck with the sticky backed rubber insulation.
For windows that you don’t need to open regularly, another option is to “caulk” them shut, but not with the usual caulk, but with a temporary caulk. Manufacturers like DAP or Red Devil make a clear temporary caulk that can be applied in the winter to seal drafts and easily pealed off in the spring to once again make the window operable. I have to caution you though to not use this type of caulk for any window that may need to be opened for emergency escape, such as a bedroom window.
Finally, if you are just totally tired of the caulking and weather-stripping chores, you can consider “replacement” windows which can be installed without tearing out any siding. Replacement windows are made to fit the existing windows openings and can be installed by just removing the operable windows sashes and leaving the frame in place.