Functionality

A properly maintained double-hung window opens and closes easily, stays in position without falling, and seals tightly when closed.  Operable upper sash are particularly fine on hot summer nights.  With both sash open on a still hot night, cool heavy air will enter at the sill and warm light air will exit at the head exchanging hot air inside for cool air from outside even without a wind or cross ventilation.

The most common problem is broken sash cords which connect to balance weights inside the window jamb.  These cords can be replaced. After sixty years, it isn't surprising to have a little paint build-up interfering with smooth operation.  This paint can be removed, a new tight coat of paint applied, and the guide tracks lubricated with wax for effortless operation.

With all parts working correctly, the latch will pull the window tightly closed.  With weatherstripping added, the window will have even better infiltration resistance.