For those that live in the colder states, it is well known that window heat loss is the biggest drain on your home heating
bill. Plastic window covering kits work ok, but they are tedious and unsightly. Then you have the mess to remove in the sprintime. Thick curtains stop some wind, but are not always practical.. Living in northern Michigan I have tried several different methods, and finally found one that is excellent. the springtime reversal is simple also.
The first thing you do is wipe the window off along every gap area. Both sides of the moving sahes, and the top and bottom as well. Anywhere there are moving sahes there are air leaks. These areas are the places we are sealing up, so they need to be free of all debris.. I use caulk. A $1 tube of caulk seals about ten windows. White windows, use white caulk. There are plenty enough colors available to match just about any color windows you may have. Clear caulk is also available if you choose.
Snip the end , so there is a very small hole, and just a fine bead of caulk emerges from the tube when you sqeeze. Go over all the areas of the window that has moving parts with a very fine bead of caulk. Just enough to seal the cracks. keep a wet rag handy in case you need to wipe some excess off, or just to smooth the caulk flat if you wish..
Seal up one window, and give it a candle or incense test to see for yourself that the wind is stopped, and the smoke just goes straight up. Upstairs windows are the biggest heat loss areas of the whole house, so this would be a good place to start. One window will take about five minutes of your time. So, in about an hour, you can do all of the upstairs windows, if you have them.
Opening the windows in the springtime is easy. Take a razor knife, and just slice the blade through the caulk, and the window slides like it used to. You do not have to remove all the caulk, as long as it is cut to permit the window to move freely.
So, for $1, and an hour in the fall and spring, you will be amazed at the results. At least do yourself a favor, and do one window for a test. I promise you will be pleased with the results.