I had replacmemt windows put in my house 3 yrs ago .This was to take care of a drafty house. It didnt work . I never thought that the new replacment windows could be the problem until the other windy day I noticed that cold air was leaking past the window stripping and coming threw the sides of the sash . I talked to the manufacturer of my windows who told me all double hung windows leak air . That because I was overly sensitive to the cold that I noticed it ,and to give him a week to figure out how to fix this problem. I did talk to other window manufacturers who told me that you should not feel any wind leakage until around 50 mph sustained winds. I told this to my window guy and he said they are lying to me, that all windows leak air at low mph winds . Who is telling me the truth? The day I noticed my windows leaking air, the wind was blowing about 20 mph gusts. HELP!!!!