The last option is probably the cheapest and easiest. Here’s a tutorial focused on replacing glass in steel windows. You’ll want a hard-coat Low-E glass for this just like the storm windows and installing it is just a matter of digging out the old putty and glazing points and swapping the glass then re-glazing the window. I don’t want it broken out or even swapped if possible, but if it’s a matter or trashing your windows or swapping the glass I see this option as a win because it saves historic windows. I will preface this by saying that I am a huge fan of saving and preserving historic wavy glass. If you don’t have storm windows or your windows won’t accommodate them like with historic steel windows then the next best option is to replace the glass in the windows themselves. It is often just a matter of swapping out the existing glass with a Low-E substitute and for a very minor cost you have a big gain in efficiency. You don’t necessarily need to build new storm windows. You’ll need the hard-coat Low-E glass for this application and it can be very effective at upping the efficiency of your windows, often even beyond that of new replacement windows with double-paned Low-E! The most effective way to use Low-E glass in a historic window is by adding an exterior storm window with Low-E glass. I believe that in historic buildings there are two ways for Low-E glass to be used effectively. However, it can be used very effectively in single-paned form as well so that’s what I’ll be focusing on here today. It is used heavily in double-paned glass applications which if you’ve been a reader for long you know I am not a fan of due to their short lifespan and high failure rate. Low-E has some definite benefits whether you live in a hot climate or a cold climate. Even if you use a hard-coat Low-E in south Florida or Phoenix you will still enjoy the benefits of decreased heat transfer. Hard-coat Low-E can be used in single-paned applications and is still very effective for all but the most southern climates. Soft-coat is usually more effective at blocking heat than hard-coat but it can only be used in double-paned applications. You may hear your glass supplier talk about soft-coat and hard-coat Low-E and be wondering which one you need. In double-paned windows, the Low-E coating is typically applied to the sides of the glass that face each other in the air space so that it is protected from any exposure at all. In single-paned applications you always want the Low-E coating toward the interior of the building to protect it from hazing and premature wear. So knowing which side is coated is imperative to good performance. The Low-E coating is a micro-thin layer of reflective materials like tin or silver that is applied to the surface of the glass. In the summer it keeps the heat from getting in and in the winter it keeps the heat from getting out. I could get very science geeky here but Low-E glass is basically good at preventing heat from passing through it. Low-E glass attempts to block high amounts of UV and IR light while allowing as much Visible Light in as possible. Infrared Light (IR) Wavelength: above 780.Ultraviolet Light (UV) Wavelength: 310-380.The sun’s light comes in a few forms and they each have a unique range of wavelengths. It works by blocking certain wavelengths of light but allowing others through. So, a low emissivity glass will emit less heat than one with high emissivity. Emissivity refers to the amount of heat that the glass is able to emit. Low-E stands for “low emissivity” and has become a standard material for windows and doors since it first arrived on the scene in earnest in the 1980s. I get a lot of questions about making old windows energy efficient and when the temperatures start to dip the questions ratchet up. I’ve talked about the Different Types of Glass before and their relative energy efficiency but I wanted to dig into Low-E glass a little today so you can see if it is right for you.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |