Tag Archives: low E glass

Low E Barndominium Windows

Being a life-long baseball fan, my first introduction to “Low e”, was former Mariner, Ranger, Angel, Indian, Blue Jay and Tiger relief pitcher Mark Lowe, who could chuck a rock as high as 101 miles per hour!

OK, not so funny, but it does illustrate how little I (and most people) knew or understand about low e windows.

For decades most post frame buildings were either cold storage, or rarely heated structures. With more and more post frame buildings being used as climate controlled homes, barndominiums and shouses (shop/houses) more efficient windows are needed, if not required.

What exactly is low e glass? Here are a few key technical terms about low e glass:

Low-emissivity: Low e glass coatings work by reflecting or absorbing infrared light and ultra-violet rays. A window with low e glass does a better job of keeping heat in during winter and out during summer.

Trickle VentU-factor measures how easily heat flows through a product. Lower numbers keep heat or cold exactly where you want it. Each state has its own set of U-factor ratings within its Building Codes.

Solar Heat Gain Coefficient (SHGC) tells how much heat radiation – due to sunlight – a window lets in. If heating your barndominium is your main concern, a higher SHGC can help offset some heating costs. In warmer climates, where air-conditioning costs are a bigger factor, look for a lower SHGC number.

Windows manufactured with low e window coatings typically cost about 10-15% more than regular windows, however these windows can dramatically reduce energy loss by as much as 30–50%.

A low e glass coating is a microscopically thin, virtually invisible metal or metallic oxide layer deposited directly on surfaces of one or more glass panes. This low e window coating reduces infrared radiation from a warm pane of glass to a cooler pane, thereby lowering U-factor. Simply put, a lower U-factor equals a more energy-efficient window.

Different types of low e glass coatings have been designed to allow for high solar gain, moderate solar gain, or low solar gain. A low e coating can also reduce a window’s visible transmittance (visibility through glass) unless you use a spectrally selective coating. Spectrally selective coatings are optically designed to reflect particular wavelengths but remain transparent to others. Such coatings are commonly used to reflect solar spectrum’s infrared (heat) portion while admitting a higher portion of visible light. They help create a window with a low U-factor and solar heat gain coefficient but with a highly visible transmittance.

Spectrally selective coatings can be applied on various types of tinted glass to produce “customized” glazing systems capable of either increasing or decreasing solar gains according to aesthetics and climatic effects desired.

All new windows have National Fenestration Rating Council technical labels applied, making it easier to understand above information.

If you live where heat/cold fluctuations are minimal, low e windows are probably not high on your list.  Living here in Northeast South Dakota where summers hover around 100 degrees and winters -20 to -40, you can bet low e windows are always on my shopping list when constructing a new post frame building.

Double Hung Windows

True confession time….. (‘most everyone loves it when I fess up to something, don’t they?)….

Double Hung Pole Barn WindowI have never sold a double hung window to a client, installed one as a builder, or owned a building which had double hung windows.

Whew – I feel so much better having gotten this off my chest.

There are lots of choices to make, when it comes to deciding upon windows for a new post frame building. Often times it comes down to the two Bs (not B.S.) – benefit and budget.

The style of the window is going to play a large part in the Bs. Sliding windows and single-hung are going to be very similar in price per square foot of glass.

For a traditional style with many other benefits, consider double hung windows. Double hung windows are designed to open from the top or the bottom. The top sash slides down and the lower sash slides up. Single hung windows look similar, but only the lower sash opens. Due to more moving parts, double hung windows will cost more. For a fairly standard size, such as three foot wide by four foot tall, this cost difference is about $50 per window. The versatility of double hung windows provides for a wide range of ventilation options, but the benefits don’t stop there.

Most modern double hung windows are designed for ease of cleaning. Both the upper and lower sashes tilt in. This means that you can clean the outsides of upper story windows from the inside, eliminating the need to hassle with ladders, scaffolding, or long-handled tools.

My wife’s experience…she tells me she had double hung windows in the last house she lived in, and LOVED them.  She said she could clean the windows totally from the inside, and didn’t have to run outside, and drag a ladder around to clean the outsides. If the weather was cold, windy, same thing…cleaning from the inside went faster and with less hassle.  She also could reach the interiors of the window frames much easier.

Modern double hung windows are designed with double or even triple panes with an air pocket sandwiched between. This provides for energy efficiency without the trouble of putting on storm windows or plastic sheeting.

There are some valuable features to look for when choosing double hung windows. One of these is low E glass, which restricts ultraviolet rays. In warm climates, heat-absorbing glass may be desirable. Look for a specially designed balance system (such as the Silver Line® 3000 Series) which eliminates the weights and pulleys of older double hung windows. For just a few extra dollars double pane windows can be filled with inert argon gas instead of plain air. Better manufacturers offer a limited lifetime warranty on their windows, valid as long as the original purchaser owns the pole building.

For opening windows on the second floor of a pole barn, double hung certainly appears to be a choice worth considering.