Energy Efficient Windows Melting Houses & Cars

Energy Efficient Windows Melt Vinyl Siding: Boston - Deb Vincequere's home in Worcester, Mass., is a mess because her vinyl siding is melting. "It's so upsetting I could cry. I'm not kidding you. I cry all the time. It's buckling, it's lifting off the house, it's curling up, it's just totally ruined," Vincequere told Team 5.

Carolyn Dillon of Watertown, Mass., is also upset with the way her home looks. "I'm horrified. I think it was almost a $10,000 job," said Dillon, who installed different vinyl siding but experienced the same melting problem. "About 15-16 pieces have dents or rolling areas in them." In both cases, local building inspectors said the damage was caused by sunlight bouncing off double-pane energy efficient windows on nearby homes.

Windows called low-e glass or low-emittance are energy efficient and even required by some building codes. But they can also warp inward and act like a magnifying glass, concentrating too much heat on nearby homes. Gerry Brady from Infrared New England recently studied Vincequere's house. "This looks like someone took a blow torch to it."

Normal vinyl siding begins to be soften and distort at 165 degrees Fahrenheit. "We had temperatures that were 248 degrees Fahrenheit," reported Brady. Both the Vinyl Siding Institute and the National Association of Home Builders acknowledge the problem, but say it is not widespread and the siding and windows are not defective.

A recent study by the association found that a combination of contributing factors must be present before the effect occurs, including concavity in the double glass panes, a low angle of sunlight and close proximity to adjacent homes. Any double-pane window can cause this effect, but the group reported that double pane low-e windows are more likely to cause the problem. "My home is ruined and at no fault of mine whatsoever," said Vincequere.

Vincequere's warranty has expired and Dillon's warranty specifically excludes damage caused by heat or reflection from windows. "I was shocked," said Dillon. Both Vincequere and Dillon told Team 5 they were shocked that no one is warning homeowners melting siding can occur. "They're not doing anything about it and that's what really bothers me," said Vincequere. A state spokesman for the state Board of Building Regulations and Standards told Team 5 Investigates they are researching the problem and their responsibility to homeowners and will discuss both at a meeting next month.

Woman Claims Neighbor’s Energy Efficient Windows Are Melting Her Toyota Prius: A SoCal woman says the energy efficient window installed in a neighbor’s condominium is melting the plastic components on cars parked in her carport. Heather Patron of Studio City was dealing with a mystery regarding her Toyota Prius. “The side view mirrors were melting,” says Patron. “Anything that was plastic on the car was melting.”

Toyota told Patron nothing was wrong with the car. After having the mirrors replaced, she noticed the mirrors on the car parked next to hers were also melting. Patron then observed a powerful beam of light that was reflecting off the window of a next door condominium, casting a concentrated beam over her carport. CBS2’s Randy Paige placed a thermometer in the pathway of the beam on a partially cloudy day. The temperature registered over 120 degrees in less than five minutes. “I’m positive that this window is what is causing the damage to my car,” says Patron.

Patron is not alone. Reports across the country have alleged damages brought on by concentrated sunlight reflected off of energy efficient windows. The National Association of Home Builders is now conducting a study on the matter. “I just don’t feel like it’s fair,” says Patron. “I feel like it needs to be known that this is happening. And a lot of people probably have damage out there, that they aren’t aware that it’s the windows that are causing this.”

The Los Angeles City Department of Building and Safety says even if the window is the source of the damage, there are no code violations involved. The department says it’s not against the law to install a window that reflects sunlight.

Energy-efficient windows intensify fire: South Buffalo, N.Y.  - Firefighters were right around the corner when fire broke out in South Buffalo Tuesday night. They made two searches of a burning Seneca Street house, but learned none of the three residents were inside. Division Chief John Mogavero says improvements to the house actually intensified the fire.

"Energy-efficient windows are fantastic, but the trouble is, not only do they keep the cold out, they keep the heat in. And when you have a fire like this, it keeps the smoke contained, the heat contained, it's an oven effect almost," explained Mogavero. The fire left $75,000 in damage to the house.

Low E Glass - A quick guide (Previous blog).

Low E Windows - A Quick Guide

Low E Glass - Types and Benefits

Summary: Low e glass windows offer insulation against heat and cold. Two types of low e glass, soft and hard coat, look and perform differently. Soft coat low e glass has a higher r value (see r values lower down).

Have you seen a new home lately? Well, I mean, have you looked at the windows from the outside at a distance? Did they appear coated or colored like some new office building? If so, there probably was Low-E glass in the windows. Low-E glass is one of the technological marvels of today's residential construction. Who would have thought 25 years ago that glass could be coated with an ultra-thin layer of metal? Who would have guessed that this metal coating would allow you to see through the glass and provide actual insulating value? Not me, that's for sure!

The E is for Emissivity: My Webster's Seventh New Collegiate Dictionary defines emissivity as "the relative power of a surface to emit heat by radiation." Emit means to "throw or give off." Okay, so Low-E glass obviously is a special glass that has a low rate of emission. In other words, if there is a heat source inside your house (or outside!), the glass bounces the heat from that object back away from the glass. So, in the winter months, if you have Low-E glass in your home, much of the warmth (heat) given off by the furnace and all the objects which the furnace has heated, is bounced back into the room.

In the summer, the same thing happens but in reverse. The sun heats things up (the air, sidewalks, driveways, next door neighbors bricks, etc.) outside of your house. This heat radiates from those objects and tries to get into your house. Of course, it tries to take the path of least resistance, that being the glass. With Low-E glass much of this heat bounces off the glass and stays outside.

The Two Types of Low-E: There are two types of Low-E glass: hard coat and soft coat. As you might imagine, they have different properties. In fact, they actually look different. Hard coat Low-E glass is manufactured by pouring a thin layer of molten tin onto a sheet of glass while the glass is still slightly molten. The tin actually becomes "welded" to the glass. This process makes it difficult or "hard" to scratch or remove the tin. Often this glass has a blueish tint to it.

Soft coat Low-E glass, on the other hand, involves the application of silver, zinc or tin to glass in a vacuum. The glass enters a vacuum chamber filled with an inert gas which is electrically charged. The electricity combined with the vacuum allows molecules of metal to sputter onto the glass. The coating is fairly delicate or "soft."

Furthermore, if silver is used (and it often is) this coating can oxidize if exposed to normal air. For this reason, soft coat Low-E glass must be used in an insulated glass assembly. Sealing the soft coating in between two pieces of glass protects the soft coating from outside air and sources of abrasion. Also, the space between the two pieces of glass is often filled with argon gas. The argon gas inhibits oxidation of the metallic coating. It also acts as an additional insulator.

The two types of Low-E glass have different performance characteristics. The soft coat process has the ability to reflect more heat back to the source. It typically has a higher R value. R values are a measure of resistance to heat loss. The higher the R value of a material, the better its insulating qualities. Look at Table 1 for a comparison of R values and the different types of glass.

GLASS R VALUES

Type of Glass                                                    R Value

Single Pane regular glass                                       0.85

Clear Insulated Glass 7/8 inch overall thickness    2.08

Hard Coat Low-E insulated glass                           2.45

Hard Coat Low-E insulated glass with argon         2.75

Soft Coat Low-E insulated Glass                           3.50

Soft Coat Low-E insulated glass with argon          4.35

Low E glass helps to reduce condensation on glass. The inside surface temperature of the glass is warmer. The differences can be dramatic. Imagine a cold night with an outside temperature of 0 degrees and a 15 mph wind. The inside temperature of a single pane window would be approximately 26 degrees. Regular double pane glass might register 35 degrees. Hard coat low E glass would be very near 49 degrees. And weighing in at champ would be soft coat low E glass at 62 degrees. Some glass manufacturers have gone even farther. They have suspended thin, low E transparent films in between pieces of glass. This system has excellent performance characteristics. Some of these films can block 99.5 percent of UV light. Some boast an insulating value twice that of soft coat low E glass. Low E glass is worth the price, especially since houses tend to lose 25 percent of their heat through windows.

Ten Window Manufacturers and Their Type of Low E Glass.