Vinyl windows are windows that have a plastic (vinyl) frame. There are a few parts of vinyl windows that are not common to any other window types because of the different construction method.
These parts make vinyl windows unique in their construction.
Almost all vinyl windows have a drainage system built into them. This is because vinyl windows are built with a channel the the window sash closes into creating a tight seal.
However, this does not give water the opportunity to escape so it goes into channels that direct the water into the indie of the sill. The water drains out of the two miniature vents in the corners of the windows.
The drains have screens to prevent insects from building nests or living in the empty channel.
Molded Meeting Rail Seals
The meeting rails are the top of the bottom window and the bottom of the top window that meet on a double hung window. This part of the window is very important as it seals the window from air coming in.
On vinyl windows, the seals on the meeting rails are part of the molded rail which is important to note because on other types of windows, the seals have to be added afterwards leaving room for those seals to fail.
Vinyl Window Options
Vinyl windows offer options that other windows can not because the frame of the window is hollow. One of these options is aluminum reinforcement throughout the window frame.
Because vinyl is not a very strong material compared to wood or aluminum, the weight of the glass can make the vinyl window fail prematurely due to seals breaking under pressure. The aluminum supports the window frame and lengthens the life of the insulated glass.
The window frame can be insulated with urethane injected foam insulation. These window frames have an R-value between R-10 and R-20 depending on the frame width.
This option also strengthens the window making it last longer than conventional vinyl windows.