Replacing Windows? Ask About Condensation Resistance.

Posted by: Ken Mariotti

Most people know about the National Fenestration Rating Council (NFRC) rating system and label that shows consumers how a window performs in several areas, such as, thermal insulation, solar heat gain, visible light transfer and air leakage. What most people don’t know is that the NFRC also rates a window’s condensation resistance (CR). While, the U-Factor, which rates thermal insulation or how well a window prevents heat from escaping, is most important. For cold climate like Illinois, another important rating, maybe CR. Since this rating is optional for manufacturers to include on their Energy Star label, it may not be available, however it is important to consider when purchasing new or replacement windows.

Condensation on your windows can be worse in winter when the outside temperature is below the dew point of the indoor air. Water or frost appears when warm moist air comes in contact with colder dry air.

Maybe your windows have a single pane of glass, which provides no insulation. Since condensation is more likely to form on cold surfaces than warm surfaces, there are water droplets or ice on the glass. If this describes your windows, be aware that upgrading your windows to today’s technologies will make a significant difference.

Early double-pane wood windows with aluminum spacers can experience condensation. The aluminum spacer separating the two panes of glass is very conductive, thereby transferring in the cold from the outside. Spacers are located around the glass edges and so conduct heat from the inside pane to the outside pane. The area where the wood meets the glass can develop condensation, freeze, thaw, and eventually rot the wood.

Today’s windows are engineered differently. Frankly, the most important part of the window to resist condensation is that spacer that keeps the panes of glass apart and seals in the gas. Today’s spacers are made of less conductive stainless steel, U-shaped tin steel, and foam polymers. Low-E and gas filled glass panes reduce temperature transfer between the inside and outside. Add the frame, to this list of improved materials, and you essentially have the features that are measured in the NFRC U-factor ratings. The NFRC recognizes three parts to a window: the center-of-glass, the edge-of-glass, and the frame. The lower the U-factor, the better the window is at keeping heat in – particularly important during winter’s heating season.

Some condensation is expected and can result from any number of variables, including a homeowner’s lifestyle. Dryers that are not vented to the outside, gas cooking without using the vent, room humidifiers or forgetting a boiling teapot, our lifestyle choices all contribute. However, sloppy, wet, sweaty windows are unsightly and left unchecked, the constant moisture can lead to serious damage of the windows, window coverings and walls.

If you’re in the market for replacement windows remember to ask about the features that contribute to condensation resistance. For example, our colder climate makes aluminum frames a poor choice, but if you must have this for your modern home make sure the window you choice has thermal breaks. Second, opt for Low-E and argon or krypton gas fills between double or triple panes. Third, ask about warm-edge spacers, which are no-metal or spacers made of less conductive metals.

With so many window choices out there, it would be nice to have a simple rating system, like the U-factor to compare windows for condensation resistance. The NFRC  and others, have attempted to articulate a common measurement for manufacturer’s to use, which is called the CR scale of 1-100, with a higher number representing more resistance to the formation of condensation. A single pane wood window might have a rating of 15, while a triple-pane wood window may achieve a rating of 75. A cold climate, like Illinois, ideally would opt for a rating over 50.

So why aren’t window manufacturer’s required to include the CR rating on their windows? In a nutshell, while it’s a valuable metric to obtain, there are still multiple ways to measure condensation resistance and limitations to either rating method.  It may come back to the homeowner’s lifestyle choices contributing to indoor condensation. For example, shades, curtains, and blinds tend to reduce the amount of airflow across the window. This allows the window to cool and increase the likelihood of condensation.

Woodland Windows and Doors have done the research about condensation resistance and have discovered that a single rating probably isn’t a particularly useful number. However, selecting new or replacement windows that reduce the relative risk that you will have condensation is a very worthwhile pursuit. If you need to maintain a higher interior humidity during the winter months, for health or comfort reasons, you want to pay attention to the edge-of-glass details. Or maybe you just want to be sure you understand the important features and specifications of the windows you buy. Ask Woodland -Woodland knows. 

What are the Benefits of Argon Gas Replacement Windows?

When it comes to purchasing replacement windows, one of the main concerns for most homeowners, besides the style and the design selected, is how efficient the windows are. It is obvious that most people purchase replacement windows for energy saving purposes. Argon gas is used in modern replacement windows. Argon provides energy-efficiency, hence reducing heating and cooling bills.
 

Argon is one of the noble gases that make an important part of energy efficient windows. Argon gas is about 30% heavier than air and transfers approximately 48% less heat than air. For this reason, it is used to make a barrier to prevent heat transfer. Noise, as well as heat energy, has a difficult time moving through Argon.
 

Argon gas makes about 1.28% of the air we breathe, and is the third most common gas in the atmosphere. It is inflammable and nonreactive. Argon is odorless, colorless and absolutely nontoxic as a liquid, solid, or gas. It is totally harmless. Even if the window breaks, there is no need to panic at all since the gas is completely safe.
 

Xenon and krypton are also noble gases, but they are slightly heavier than argon. Although Krypton is also used in windows, it is quite expensive to produce. Thus, when it comes to replacement windows, Argon is the most preferred inert gas. The measure of thermal resistance or incremental R-Value that shows the level of energy efficiency may improve the performance of your windows. Adding an Argon gas to the panes of the window may help top boost energy efficiency as it minimizes solar heat gain.
 

While replacement windows filled with argon gas are expensive, the extra costs for these windows are usually offset by their long term benefits. In other words, the energy savings you will enjoy in the future will eventually cover the huge money used to purchase these windows. The amount you will save on heating costs over the course of their lifetime is more than worth the initial cost.

Unlike other systems of measurements such as U-value and R-value, windows with argon gas are capable of limiting leakages. For example, during the summer, windows featuring argon will keep the air inside the house cool. In the winter seasons, these windows will keep warm air inside the home saving on cooling bills.

Argon Gas Replacement Windows

Today, many replacement windows include argon gas as an insulating material which is filled in between the panes of a window. Adding argon gas in replacement windows increases the overall efficiency of your home.
 

Technically speaking, argon gas is an odorless, colorless, invisible noble gas that occurs naturally in the atmosphere. It is non-toxic, nonflammable, and completely safe. This is an inert gas, meaning it doesn’t form true chemical compounds as opposed to other noble gasses (krypton, neon, xenon and helium).
 

In addition to improving the thermal performance of replacement windows by reducing heat transfer between the panes, argon is also used in radio tubes, gas-filled electric bulbs and in production of metals such as zirconium, uranium and titanium.
 

Originally, the space between the window panes was filled with dry air or nitrogen. The panes were airtight in the window sash. The double-panes or triple panes provided a form of insulation. Nevertheless, this method proved ineffective as air currents in the panes pushed any heat to the top of the unit, leaving cold air at the bottom. But argon gas is a slower-moving and less conductive gas. When pumped between the double or triple panes, it reduces conduction and lowers the convection currents through the glass. 
 

Argon windows are super-efficient because it is a heavy gas (about 195% heavier than air). Thus, argon gas is better at retaining heat in your home during the long winter months and keeping cool air in during the warmer months.
 

Argon-filled filled are becoming a more and more popular choice for many homeowners due to several reasons. The following are a few benefits of installing argon-filled windows in your home. Number one, windows filled with argon gas will increase the thermal transmission or U-Value of your windows. The rate of heat transfer is usually measured by what is known as U-Value. The lower the U-Value of a window, the lower the rate of heat transfers through that window. Number two, argon gas can help in limiting condensation in your windows. Number three, it will improve the soundproofing features of your house as well as ensuring the working efficiency of your heating and cooling systems.
 

Reasons to Choose Argon Gas Replacement Windows

Argon gas is an odorless, tasteless and colorless gas that is extensively used in making fluorescent lights, light bulbs, photo tubes and now replacement windows. It is denser than normal air and has a very low level of chemical reactions. In other words, unlike oxygen, argon gas will not corrode or react with any type of window material. These windows include a vacuum-packed unit that is filled with argon gas between panes of glass to improve energy efficiency.
 

Argon is a non-toxic and inexpensive gas that is typically used to make replacement windows in order to stop frost from forming at the bottom of the windows. Argon windows also help to increase sound proofing features of a home, preventing unwanted outside noise from entering the house. Today, argon windows are gaining ground and are becoming a more popular choice for many people in the greater Chicago area.
 

There are double-pane glazed and triple-pane glazed argon filled replacement windows available. In order to place the gas between the panes of glass, the manufacturer sucks out air from between the glass panels, leaving a void, then pumping in the argon gas to fill the area. Since it is denser than normal air, it will redirect inside heat back into the home. Also, this can help to minimize condensation on the window as the inside part of the glass will remain warmer throughout the winter season. Additionally, argon gas can help reduce drafts and cold spots..
 

As said earlier, the noble gases are denser and heavier than air, so their particles do not move freely. Having inactive gas molecules between the panes of glass prevents warmer inner air from escaping in the winter seasons, saving money on heating costs. With the reduced heat loss, the R-value of the window is increased. A window’s R-value measures its ability to prevent heat from escaping. A double-pane glazed window without an argon gas has an R-value of about 1.8. A double-pane glazed window with an argon gas has an R-value of about 3.0, making it more energy efficient.
 

If you aren’t sure of whether or not to invest in argon filled replacement windows, consider your constantly rising energy costs for the last few months. Now try to imagine how much you’d save with argon replacement windows. Besides saving you money on utility bills, argon gas replacement windows protect your furniture against fading since these windows have the ability to block UV-rays. This, again, will save you more money on replacing furniture, carpeting, curtains, and other similar items.