A window can be built like a tank and the glass can be as thermally efficient as the wall around it, but if it doesn't stop the wind and weather it might as well be an empty hole in the wall. Furthermore, if the window never needs to open for ventilation, cleaning or egress (emergency), one could merely "caulk" or seal it shut and the problem of air-infiltration is solved. However, it's almost always desirable to be able to open the windows occasionally for one reason or another, hence the need for weather-stripping.
Our Magnum Replica Windows will arrive with our WindowLogic Weatherstripping System included, a state of the art, comprehensive kit that we developed.
In the world of wooden windows, the universal solution to air-infiltration around the vertical edges of the sash are "Jamb Liners". The jamb liners mount on either jamb side and the rigid vinyl "springs" against the edges of the sash to make a seal. As long as the sash edges are smooth and the jamb liners continue to "spring" to make contact, the system works pretty well. If one doesn't mind seeing a great deal of either white or beige vinyl around the perimeter of the sash it's a fairly acceptable solution.
There is essentially no weather-stripping on the edges of most contemporary wooden windows. The Jamb Liners act as weather-stripping by springing to and mating with the wooden surface of the edges of the sash.
This approach works well when the windows are new, and all surfaces smooth.
Some find this "protruding" Jamb Liner concept less than desirable because a great deal of vinyl is visible and the vinyl is usually only available in white and beige.
While almost all windows use jamb liners to seal the vertical edges of the sash, they also almost always use "Hollow Bulb" seals for the horizontal applications like at the Meeting Rails, Bottom Rail and Top Rail. There is a great deal of competition in the replacement window market and to a great extent it's price driven. Therefore, it's critical for manufacturers to minimize their material costs. By far the cheapest type of seal is the "Hollow Bulb" since it's the easiest to make. Unfortunately, the hollow bulb is also the most prone to "extended memory" wherein the material compresses but after time fails to return to it's original shape, effectively diminishing it's ability to seal properly. Furthermore, there is no insulation factor afforded by the hollow bulb style either.
There are several reasons we do not use standard jamb liners in the Magnum Replacement Sash Kit. The primary of which is that they are so intrusive and have such a contemporary appearance. Another is that because they are typically made from standard formula PVC they are essentially un-paintable (considering the scraping action the sash edges would execute on them) and therefore inappropriate for many of our customer color schemes.
While the Magnum uses a jamb liner of sorts, it is, a) very minimal and inconspicuous and, b) paintable so that it virtually disappears into the window frame. Because of the design of our jamb liner, we can utilize a much more appropriate weather-stripping system on the vertical sash edges.
Foam Filled Vinyl Seals (Q-Lon)
Schlegel and Amesbury are the two most well known and highly regarded weather-stripping manufacturers in the world. Their premier product is the Q-lon bulb seal. Here's how they describe the product...
"Open-cell urethane foam core and clad in an embossed polyethylene. UV stabilized, paint resistant liner."
Despite the fact this product is far more expensive than typical hollow bulb seals, the difference is worth it in longevity and performance. These seals are well known for their lack of "memory", always springing back into their original shape to make a good seal year after year.
In some applications the Magnum might also use "Fin Pile" seals. These are particularly appropriate for sliding applications like occurs when double-hung windows are operated. Again, known for their positive seal, lack of memory and longevity, these seals are also a staple in the vinyl replacement window business.
In either case, because we know the importance of good seals that perform for the life of the window, we use only the finest and most high-performance weather-stripping products in the Magnum.