Without skipping a beat, we’re going to move right along with our exploration of heat transfer and the way it impacts the aluminum window and vinyl window manufacturing industry. There are a lot of ways that the design and construction of windows and doors of all shapes and sizes have been modified and improved to better protected against unwanted heat loss and heat gain. There is a saying around the window manufacturing industry that goes something like, “if it looks like a window and feels like a window, but doesn’t keep the outside out, then it’s not a window; it’s a screen.” This is actually not a saying in the window manufacturing industry. Today is probably the first time it has formally been coined, and the ripples of this moment will probably go on to shape the window-manufacturing world and turn the universe on its head. The core message behind this newfangled saying is simple, if you aren’t protecting the sealed indoor environment of the home or workplace from the elements of the outside world, then you’re missing the fundamental purpose and goal of the replacement window and window supply industry altogether.

Last week we talked a bit more about conduction and moved on to convection (a closely related mode of heat transference). Today and tomorrow we are going to broach a new topic. Our term we’ll be looking at is CRF, or Condensation Resistance Factor. This is it people, the culmination of all our heat transfer and condensation knowledge! This rating is a standardized measure of a window’s ability to effectively block the condensing of water vapor on its panes… essentially by being a more efficient product. As we’ve learned recently, heat transfer has everything to do with condensation. If a window is poorly stopping the transfer of heat or cold, then condensation will result if the humidity reaches the proper level. Next time we’ll finish up our look at CRF and move on into the great unknown.