Have you ever found yourself operating a 200-year-old Georgian sash window and wondering how a 50-pound timber frame can be lifted with such effortless ease? In contrast, the five-year-old vinyl window in your bedroom puts up quite a struggle when being opened and closed – it’s almost as if you’re trying to lift a heavy weight at the gym. However, it is not magic that makes these windows operate with such ease – it is simply the laws of Newtonian physics at play. For Sash Window Repair London, visit https://www.sashwindowpreservation.co.uk/services/sash-window-repair/london/
Modern vinyl windows contain mechanical spring balances that are housed within the jambs of the window. These spring balances create friction between the plastic tracks and the window frame, causing the window to bind over time due to the accumulation of dust and the deterioration of the plastic and springs under extreme heat.
In contrast, traditional sash windows use a frictionless system that was developed during the 17th century, utilising cast-iron or lead counterweights that are connected to the sash by a cord and pulley system. In these systems, the weight of the sash itself is evened out with the weight of the counterweights that are hidden within the wall cavity of the window. As a result, there is no net force acting upon the sash window.
It is not necessary to expend energy to lift the 50 pounds of timber frame; merely enough force needs to be applied to overcome the initial friction that exists between the sash and the pulley system. Unlike the mechanical springs that are utilised within vinyl windows, gravity is a force that does not degrade over time. Should the cotton cord and lead weights remain intact, then the wooden sash will continue to open and close throughout the centuries – another way in which physics proves to be stronger than plastic.
