WINDOWS - Frequently Asked Questions

1. How should I evaluate the energy performance of a window?

Look for products that are tested and approved by the National Fenestration Rating Council (NFRC). This includes testing the U-value of a window. Look for the sticker on the window. Another place to look for information on energy efficiency in windows is: U.S. EPA Energy Star Homes Program web site. NFRC and Energy Star give you a measure of a windows "Thermal Performance Only".

• 1-A. How Should I evaluate structural, air infiltration and other performance issues?

AMA and NWWDA Ratings

American Architectural Manufacturers Association (AAMA)*
National Wood Window and Door Association (NWWDA)*

* Have set test specifications standards for windows and doors

How the Standard Works

The standard defines four mandatory performance requirements for a completely fabricated window:

• Structural integrity to withstand wind loads

• Resistance to Water Leakage

• Resistance to air infiltration

• Forced Entry resistance

Actual windows are tested by independent labs and graded by their "Design Pressure" performance.

The following table shows the minimum Performance Grade required for each class.

Window/Door Performance Grade Structural Test Pressure Water Resistance Pressure Residential (R) 15 22.5 psf 2.86 psf Light Commercial (LC) 25 37.5 psf 3.75 psf Commercial (C) 30 45 psf 4.5 psf Heavy Commercial (HC) 40 60 psf 6.00 psf Architectural (AW) 40 60 psf 8.00 psf

A window rated "R" 15 just passed for residential use only.
An "R" 30 or 45 rated window will perform much better.

2. What is air infiltration?

Air infiltration refers to the movement of air at a different temperature through the different interfacing surfaces of the sash and frame. Look for windows that are designed for absolute minimum air infiltration.

3. What is a "rough opening"?

The rough opening is the opening in the wall that the window or patio door fits into. Normally, the rough opening must be sized 1/2 inch larger than the frame in both width and height.

4. What does it mean to have a "clad" wood window?

"Clad" refers to the covering on the exterior window or patio door unit. From the inside, you see the beauty of wood while the aluminum clad "shell" on the outside ensures the life of your wood windows for many years.

5. What does the term "failed" mean and how can you tell when a window has "failed"?

You know a window has failed if there's moisture in between the panes of glass. There are two types of window failures:

1. a seal failure: moisture (condensation) is leaking into the space between the panes.
2. a window failure: the window is no longer keeping out the elements.

6. Can old-style windows be custom made?

Yes. One affordable option that also maintains the historic integrity of a home is to replace an old wood window with a new wood window of the same style.

7. What window material do you recommend for a house in the D.C. Metro area?

Window material choices vary by region. In the D.C. area, houses use mostly vinyl, fiberglass and wood windows, whereas in the Southwest, more aluminum windows are used. This has a lot to do with the building codes, and the fact that aluminum conducts heat and cold. Fiberglass and Vinyl are very popular in this region.

8. Please explain the (U) and (R) values and how they rate a window's insulation capabilities.

One way that insulation is created is with dead-air space between panes of glass. Therefore a double-paned window gives more insulation than a single-paned one. Other factors contribute to the insulation qualities of a window, such as the gasket, the material type, and the gas used in a gas-filled window. The U/R value tells how the product insulates. It is a formula derived from the efficiency of the product, and that formula takes into account many of the factors just mentioned. A good R measurement is a high one, while a good U measurement is low since U is the reciprocal of the R. Homeowners are more interested in the R value, while builders are interested in the U value.

9. What is low-E?

Low-E, or low emissivity, refers to how a window reflects certain length waves. A window with a good low-E lowers your energy bill because in the summer it reflects sunlight and in the winter it absorbs it to help in heating your home.

10. What are some reasons why I might want tinted windows in my home?

Tinting on glass is used for more than just keeping out the sun. The tinting, which comes in either gray or bronze, cuts light into the home, and keeps heat out.

11. What is the reason for injecting gas into double paned windows?

Two types of gas are used to fill the space between panes of glass: argon and krypton. These gases are denser than air, which contributes better insulation. Krypton is even denser than argon, hence slightly more expensive.

DOORS - Frequently Asked Questions

1. How should I clean my wood door?

Cleaning with a dust cloth, as with furniture, is the most important step in maintaining the finish. Dust collection on the surface, particularly the exterior, absorbs and holds moisture on humid days and damp evenings. After dusting, you may wish to apply a furniture polish, but be sure to remove all excess polish and wipe dry. Do not wash with water or use heavy waxes.

2. Can I purchase a custom door?

Yes. The Window Man offers handcrafted fine wood, steel and Fiberglass doors. Built for entryways, our doors are an elegant solution for your home. Lead time is three to six weeks.

3. What wood species are available for wood stile and rail doors?

The types of wood species available for stile and rail doors include oak, ponderosa and western pine, Douglas fir, hemlock, maple, mahogany and cherry.

4. Are 8-foot doors hard to find?

No, many companies make 8-foot doors.

5. What kinds of homes have 8-foot doors?

Purchase of 8-foot doors is regionally driven. For example, 8-foot doors are very common in Arizona for use in both interior and exterior. Most often homes with vaulted ceilings would have 8-foot doors; and homes that sell for above $300,000 are more likely to have them.

6. Do doors have energy performance ratings?

The National Fenestration Rating Council (NFRC) publishes the U-values for certified doors.

7. What is the best way to ensure that my new door will last?

The most important thing to do when you purchase a door is to finish all six sides. If all six sides are not finished after purchasing, the warranty is voided. This is the primary problem that contributes to the wear and tear on a door. The most often skipped areas are the top and bottom, and they are actually more important to finish than the other four sides. This is because moisture is going to hit that raw wood surface and affect the door, creating grooves in the wood.

8. Where should I install a fire door in my home?

Fire doors are most often used between the house and the garage. Typically a 20-minute fire door is fine for a home application.

9. What is the order of steel doors, from lowest to highest quality?

1. 25-gauge door: used as a utility door, front door, etc., but not for a fire-retarding door; the stiles are made of wood.
2. 24-gauge energy-saver door: a 20-minute fire door with the stiles made of wood.
3. Steel-edge instead of a wood edge: a 90-minute fire door with the stiles made of steel.

10. What does the gauge measurement mean in steel doors?

Gauge is the thickness of the steel. Steel doors are cut from large rolls.