Over the past few years, the process of choosing new windows has become more difficult due to the arrival of new options, designs, and manufacturing materials. Furthermore, energy costs continue to rise, making energy-efficient windows and doors more important than ever. So how do you decide? Ask the Experts!

You will find the answers to several of the more frequently asked questions below. Just scroll down the page to browse all the questions and answers.

If you have a question that isn't answered here, then please email us or use the form on our homepage to submit your query and we will be happy to assist you.... just Ask the Experts!

 

Single-Hung/Double Hung  In double-hung units, both sashes slide vertically. Only the bottom sash slides upward in a single-hung window. Ventilation area can vary from a small crack to an opening of one-half the total glass area. Screens can be placed on the exterior of the window unit.
Casement Casement windows are hinged at the sides. Hinged windows such as casements generally have lower air leakage rates than sliding windows because the sash closes by pressing against the frame. Casement windows project outward, providing significantly better ventilation than sliders of equal size. Because the sash protrudes from the plane of the wall, it can be controlled to catch passing breezes, but screens must be placed on the interior side.
Awning Awning windows are hinged at the top and open outward. Hinged windows such as awnings generally have lower air leakage rates than sliding windows because the sash closes by pressing against the frame. Screens are placed on the interior of the window unit.
Bay Window A bay window is made up of three windows. The side units project out from the building in 30, 45, or 90 degree angles. The center is parallel with building wall and is made up of one or more windows. The units can be either stationary or operating.
Bow Window  A series of four or more adjoining window units (commonly five) installed on a radius from the wall of the building.
Fixed Frame Refers to windows that are non-venting or inoperable.
Skylight A window installed in a roof and assuming the same slope. Depending on which direction they face, skylights can bring in more light and heat than windows. For example, in the summer months, an unshaded south-facing skylight will bring in more direct sunlight and heat than a window. In colder climates such as Ottawa, a north-facing skylight gives almost five times more light than a north-facing window with almost the same amount of heat loss.
Slider Both sashes slide horizontally in a double-sliding window. Only one sash slides in a single-sliding window. Ventilation area can vary from a small crack to an opening of one-half the total glass area. Screens can be placed on the exterior or interior of the window unit.

 

Window frames are available in a variety of materials including aluminum, wood, and vinyl. Frames may also be composed of mainly one material or a combination of different materials such as wood and vinyl. Each frame material has its own advantages and disadvantages.

 

Vinyl
Vinyl windows are the popular choice. They are made primarily from polyvinyl chloride (PVC) and may contain a wooden core.. They are available in a wide range of styles and shapes, have moderate to high R-values, are easily customized, are competitively priced, require low maintenance, and can be molded into almost any shape.

 

Wood
Wood frames provide higher R-values, they are not affected by temperature extremes, and are less prone to condensation. They do, however, require periodic maintenance in the form of painting or staining If wood frames are not properly protected from moisture, they can warp, crack, and stick.
Aluminum
Though ideal for high wear-and-tear environments (e.g. commercial buildings), aluminum frames cause considerable conductive heat loss and condensation. Aluminum windows would not be recommended for residential applications.

1. Head
The main horizontal member forming the top of the window or door frame. 

2. Jamb 
The main vertical members forming the sides of a window or door frame. 

3. Frame 
The enclosure in which window sash or door panels are mounted. 

4. Glazing 
Glass in a window or door; the act or process of fitting with glass. 

5. Pane 
A framed sheet of glass within a window. 

6. Sash 
A single assembly of stiles and rails made into a frame for holding glass. 

7. Sill 
The main horizontal member forming the bottom of the frame of a window or door. 

8. Muntin Bar 
Any small bar that divides a windows glass. Also called a grille or windowpane divider.

 

Typically, 75% of the exposed surface of a window is glass. That's why it is so important to chose the best glass for your windows. There are three key factors to consider in a window glass:

•  thermal insulatation in both winter and summer

•  control of solar energy

•  visual clarity

 

The Insulating effect of your windows has a direct impact on how your rooms feel during cold weather. The better insulated the window glass, the warmer your room will be. In fact, the American Society of Heating, Refrigeration, and Air Conditioning suggests that there is a risk of thermal discomfort when the glass surface temperature falls below 11°C (52°F). To ensure the best comfort in winter, choose a glass that maintains a temperature above this point during the coldest outdoor conditions. A warmer window will also help you maintain and control the relative humidity of the indoor air.

 

The table below compares the indoor glass temperature of four different types of glass against two outside temperatures.

 

	Outside -20°F	Outside +20°F
Single pane clear	4°F	30F
Double pane clear	35°F	49°F
Ordinary low-e	50°F	58°F
Quality low-e	53°F	61°F

Clear glass has been the primary material available for window panes in homes. It has no glazing.

Low_emissivity glass (low-e) has a special surface coating to reduce heat transfer back through the window.

 

Solar Control refers to a window's ability to allow the daylight to pass through the glass while filtering out solar heat. And when it comes to air conditioning costs, clear glass and ordinary low-e glass are the biggest offenders to the air-conditioning load. In fact, clear glass windows can contribute to over 50% of your air conditioning costs. A quality glass will be coated to filter the sun's solar energy.

 

	Visible Light Transmitted	Solar Blockage
Single pane clear	90%	14%
Double pane clear	81%	24%
Ordinary low-e	75%	29%
Quality low-e	72%	59%

 

Visual Clarity refers to the clearness of the glass. Quality windows are coated with different materials to block solar energy and provide thermal insulation. These coatings should not produce a haze, bluish cast, nor bronze or smoke-coloured tints.

 

There are four important factors to consider that indicate the overall quality of each window. These are:

•  Air Resistance (Factor A)

•  Water Resistance (Factor B)

•  Wind Resistance (Factor C)

•  Forced Entry Resistance (Factor F)

Air Resistance or Air Tightness is measured by applying 75 pascals of pressure - the equivalent of a steady 25 mph (34 kph) wind - to the outside of the window. Interior air infiltration (leakage) is then measured in cubic feet per minute per foot of joint space. A quality window will have an Air Resistance value of less than 0.1 cubic feet per minute per joint feet. The lower the value, the better.

 

Water Resistance or Water Tightness is measured by projecting 5 U.S. gallons of water per hour per square foot of window surface - the equivalent of 200 mm of rain in 1 hour. In addition, air pressure is increased to simulate winds varying from 35 to 76 mph (57 to 123 kph). The rating indicates the pressure attained without any water leakage.

A high-end window will have a rating of 300 pascals (6.3 psf) or more. The higher the rating, the better.

 

 

Wind Resistance is measures the wind pressure that a window can withstand without suffering breakage (shattering) or pernament damage (deformation).

A high quality window will have a wind resistance rating of 180 mph (295 kph) or better. The higher the value, the better.

 

Forced Entry testing reproduces the efforts of a well-equipped individual attemping a force entry break-in. The test has three phases. (1) Testers attempt to force open the window using tools like knifes, screwdrivers, and wire. (2) Then they attach a cable to strategic points on the window and apply increasingly stronger loads. (3) If the window continues to resist, the testers use tools again in a third attempt.

Windows which have a locking system but have not been tested for forced entry have a rating of F1. An F2 rating means the window has successfully passed the test at level 10 (150 lbs of force). A quality window will have an F2, level 30 or better which signifies that it passed the forced entry test at 250 lb of force.

 

For additional information, please visit these websites, by clicking on the names in the table.

 

Additional Expertise Here

Natural Resources Canada

Energy Star

Cardinal Glass Industries

PH Tech

Rehau