The Truth About Thermal Replacement Windows

With all of the ads out there, it's hard to tell what is true and what is somebody selling something. So what is the truth about thermal replacement windows? Here are straight answers to the most commonly asked questions about windows:

Q. What's the difference between the windows I have now and thermal replacement windows?

A. You may already have thermal replacement windows. The easiest way to check is to see if there is more than one sheet of glass between you and the outdoors. Thermal windows are always double- or triple-paned. Traditional windows are single-paned. Thermal replacement windows allow far less heat to escape your home in the winter and less heat to get in during the summer, lowering your fuel bills considerably. Most thermal windows also eliminate the need for painting.

Q. Do thermal windows really save enough energy to pay for themselves?

A. Windows and doors are typically responsible for about 40 percent of your home's heating bill. Thermal windows are typically two to four times more efficient than older single pane windows. That means you can expect your winter heating bills to drop on average about 20 percent to 30 percent. The bigger your fuel bills and the draftier your old windows, the quicker your new windows will pay for themselves.

Q. Are the telemarketing firms that call me scam artists?

A. Both legitimate firms and shady firms use telemarketing as a way to get business, so it's hard to generalize. Although telemarketing is annoying, it does not mean the company is crooked.

Most telemarketers set up appointments for free estimates. Expect to be put under considerable pressure to buy during the free estimate. Never buy windows without getting more than one estimate. Whenever hiring any home service firm, use a contractor referral service or thoroughly interview references and check records with area consumer agencies.

Q. I've seen some pretty good deals on windows at a local home center store. Is that a good way to get windows?

A. Sometimes you can get a good price at a home center, but there are several pitfalls to watch for. First of all, the best prices are typically for "bargain" windows that may not be built well and may not last long. Second, it is difficult to get a pro to install windows you buy from a home center.

Most pros realize that if something goes wrong and it is due to a shortcoming in the window, they will likely shoulder the blame. That means either you or a handyman will have to do the installation. If thermal windows are not installed exactly plumb and square, with all the appropriate insulation, you may get little or no energy savings.

Q. What is "low-E glass"?

A. Low-E glass has a special coating that blocks certain kinds of light that we can't see. The result is that it looks like normal glass but insulates better.

Q. What is argon gas?

A. Argon is one of the most popular gasses used to fill the space between the two (or three) panes of glass in a thermal window. Argon is a good insulator.

Q. With all the technical terms, how can the average homeowner make comparisons?

A. The best way to compare windows is to check for a rating from the National Fenestration Rating Council (NFRC). Most major brands of windows have a sticker on them that lists their NFRC rating. The lower the number the better. To achieve a low score the manufacturer has to build the window carefully and incorporate a variety of energy saving features.

Q. Are "maintenance-free" windows really maintenance-free?

A. Most thermal replacement windows are made of wood, vinyl or a combination of the two. Vinyl windows require no painting, inside or out. Windows are the most difficult and expensive part of any painting project, so by eliminating the need to paint windows, homeowners can usually save a huge amount of money. Switching to "maintenance-free" vinyl windows may cut your painting bills by 50 percent. Vinyl windows still have to be cleaned, so they are not completely maintenance free.

Q. Is it a good idea to buy one of the well-known brands of windows I see advertised on television and in magazines?

A. All the well-known brands make at least one line of highly rated windows. The problem is that the well-known companies may also make other lower quality lines of windows -- including some of the so-called bargain windows that are built to be cheap.

This means that you have to look beyond brand name. Many contractors install what are called "no-name" windows. Actually, the windows have a brand, just a brand no one has heard of. If you are working with a truly reputable contractor, he is not going to steer you towards a bad window -- after all, his reputation is on the line. There are many well-made no-name windows that offer consumers bang for their buck.

Q. Is window replacement a big project?

A. In terms of dollars, it's a big project. Doing the whole house may run many thousands of dollars. However, the work itself is pretty straightforward. A whole house can be done in as little as a day or two, with little disruption to interior spaces and household routines.

Q. Given the high cost of windows, does it make sense to borrow the money?

Borrowing to replace windows makes a lot of sense. You get your cozier, better-looking windows now, and the energy savings and maintenance savings will help offset your monthly payments. For most homeowners, a loan can be arranged wherein the interest costs are tax deductible, yielding additional savings. The savings will continue long after the payments have been completed.

Krypton gas is almost three times more dense than Argon. It is also much more expensive to get than Argon is. Krypton is considered a specialty gas where Argon is an everyday gas we breath. In most cases one blocks sound better and the other blocks heat better.

What is a replacement window?

Simply put, a replacement window is designed to fit into the same opening that the old window was removed from. A properly installed energy efficient replacement window will lower your heating/cooling costs, add curb appeal to your home, reduce outside noise, and operate more easily than an older window. When choosing a prime replacement window, it is important to precisely measure the existing opening and order a customized window thus reducing the chances of heat loss or air infiltration.

What window frame options do I have?

Vinyl: A vinyl window is the most popular form of replacement window due to its energy efficiency, low cost, and wide variety of options. A vinyl frame is easy to maintain and available in many colors. With vinyl frames, insist on fully welded sashes for the strongest structural integrity. Fully welded sashes reduce air and moisture infiltration.

Aluminum: Aluminum frames have become less popular since the introduction of vinyl windows. Aluminum frames more readily conduct heat and cold. Aluminum frames are also usually mechanically fastened allowing infiltration of air and water.

Wood: For elegance, wood is difficult to beat. Wood frames usually cost more than vinyl and require painting or staining. To minimize maintenance, many manufacturers cover the exterior side with maintenance-free aluminum/vinyl clad. The combination of wood and plastic resins (vinyl/aluminum clad) offer the best of both worlds - the durability of wood and the low up-keep of plastics.

What is Energy Star?

ENERGY STAR is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy helping us all save money and protect the environment through energy efficient products and practices.

Results are already adding up. Americans, with the help of ENERGY STAR, saved enough energy in 2007 alone to avoid greenhouse gas emissions equivalent to those from 27 million cars — all while saving $16 billion on their utility bills.

What is the NFRC label?

The National Fenestration Rating Council (NFRC) energy performance label can help you determine how well a product will perform the functions of helping to cool your building in the summer, warm your building in the winter, keep out wind, and resist condensation. By using the information contained on the label, builders and consumers can reliably compare one product with another, and make informed decisions about the windows, doors, and skylights they buy.

NFRC adopted a new energy performance label in 2005. It lists the manufacturer, describes the product, provides a source for additional information, and includes ratings for one or more energy performance characteristics.

NOTE: All energy performance values on the label represent the rating of windows/doors as whole systems (glazing and frame).

The information contained on the label is also available in the NFRC's online Certified Products Directory.

U-Factor

U-factor measures how well a product prevents heat from escaping. The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. U-Factor ratings generally fall between 0.20 and 1.20. The insulating value is indicated by the R-value which is the inverse of the U-value. The lower the U-value, the greater a window's resistance to heat flow and the better its insulating value.

Solar Heat Gain Coefficient

Solar Heat Gain Coefficient (SHGC) measures how well a product blocks heat caused by sunlight. The SHGC is the fraction of incident solar radiation admitted through a window (both directly transmitted and absorbed) and subsequently released inward. SHGC is expressed as a number between 0 and 1. The lower a window's solar heat gain coefficient, the less solar heat it transmits in the house.

Visible Transmittance

Visible Transmittance (VT) measures how much light comes through a product. The visible transmittance is an optical property that indicates the amount of visible light transmitted. VT is expressed as a number between 0 and 1. The higher the VT, the more light is transmitted.

Air Leakage

Air Leakage (AL) is indicated by an air leakage rating expressed as the equivalent cubic feet of air passing through a square foot of window area (cfm/sq ft). Heat loss and gain occur by infiltration through cracks in the window assembly. The lower the AL, the less air will pass through cracks in the window assembly.

Condensation Resistance

Condensation Resistance (CR) measures the ability of a product to resist the formation of condensation on the interior surface of that product. The higher the CR rating, the better that product is at resisting condensation formation. While this rating cannot predict condensation, it can provide a credible method of comparing the potential of various products for condensation formation. CR is expressed as a number between 0 and 100.

What type of glass should I buy?

Choosing the correct glass can be very confusing for homeowners. Windows units can be made with a single-pane, double pane or the most expensive triple-pane glass system. A single-pane is normally what is being removed from a typical home. The single-pane piece of glass is not energy efficient and does not have the ability to contain a low conductive gas minimizing the overall transfer of heat. The double-pane glass system is the most common for its affordability and ability to hold energy efficient glazing's and gases. The triple-pane is the most expensive option and holds the most energy efficient ratings.

Low-E

Low-emittance (Low-E) is a coating that increases a window or door's ability to diminish heat transfer, thus saving on heating and cooling costs. In addition to energy savings, Low-E also effectively reduces the amount of transmitted ultraviolet light which can damage carpets, fabrics, and drapes. We encourage all homeowners to insist on a window with a Low-E glazing.

Low Conductive Gas filled units (Argon Gas or Krypton)

An improvement made to the insulating performance of windows is the use of Argon or Krypton gas between the panes of glass. Normally, the space is filled with air or dry nitrogen prior to sealing the window panes together. Filling the space with a less conductive gas minimizes the overall transfer of heat between the inside and outside. Argon and Krypton are much heavier than air, making it more difficult for warm or cold air to pass through.

Will replacement windows fix my condensation problem?

Condensation could appear on even the most expensive windows but new technological advances have greatly reduced this problem from occurring. A technological advancement to make note of is the Intercept PPG warm edge spacer system developed by PPG Industries. Intercept is a unique, seamless coated steel U-channel system located at the point of contact where the glass is sealed to the window frame. The U-channel spacer bar is manufactured as one continuous piece, providing excellent structural integrity and superior thermal performance. This technology provides 10% warmer indoor glass edge temperatures and outstanding argon gas retention, a higher R-Value, and excellent condensation resistance.

Are replacement windows designed to reduce noise?

All windows reduce the amount of outside noise. When replacing an old, cracked, and poorly insulated window with a new energy efficient window the noise will certainly be reduced. If you live on a heavily traveled street or if noise is a major concern of yours, then you might consider applying a storm window.