RCI Windows & Doors
One of the critical steps to achieving a truly energy efficient home is the window and door package.
Unfortunately most people give it very little thought. After all, a door is a door and a window is just a piece of glass, right? Nothing is further from the truth!
As you investigate windows and doors, remember that these items are likely never going to be changed while you live in the house, or you will incur significant cost to change them, so choose wisely.
As you select windows, you will want to gather sufficient information to make an informed decision. A great source of unbiased information is the National Fenestration Council website www.nfrc.org, as well as the Natural Resources Canada website www.nrcan.gc.ca.
There are 5 pieces of critical data you must know about any window and door:
This number measures thermal transmittance, and represents how well a product prevents heat from being transferred through it. The u-factor takes into consideration THERMAL BRIDGING through the whole window or door - the frame as well as the glass. Fewer thermal bridges result in less heat being transferred in or out of the house.
U-factor values for windows and doors typically range between 0.15 and 1.2. The LOWER the number is, the better the product.
However, keep in mind that the u-factor does not take into consideration air leakage, so even though a product may achieve a low (good) u-factor, you could still experience a draft through it.
Preventing heat from passing through the frame and glass is great, but unless you live in a vacuum chamber, you will also want to make sure that your new windows and doors will not leak. Warm air will always want to go where it is cooler, so to keep warm air in your heated home in the winter, and warm air out from your air conditioned home in the summer, choose products that are as air tight as possible. Air tightness performance ratings range from A1 to A3. The HIGHER the number, the better the product.
Water leakage is closely related to air leakage. Just as you don't want air leaks, you also don't want water infiltrating your house through your new windows. Water tightness performance ratings range from B1 to B7. The HIGHER the number, the better the product.
In windy areas, like Alberta, it is important that your windows also resist wind pressures without deforming too much, or blowing out of their frames completely. Wind load resistance ratings range from C1 to C5. The HIGHER the number, the better the product.
Keeping your home comfortable and reducing energy costs is important, but keeping your property and family safe and secure is even more important. Resistance to forced entry through the frame is measured by a rating of F1 or F2, where F2 represents a more secure product.
Given that this is a very small rating scale, and only looks at the frame, you should inform yourself on security features provided by the windows and doors you are looking at. Do they have multiple locking points? Are they available with laminated (security) glass?
There are many other factors to consider that will help you compare products and make the best decision possible. Some of these are:
* Solar heat gain: do you want to gain solar heat through your windows and doors, or is a higher insulation more beneficial? Are different options available?
* Acoustical performance: do you live on a busy road where noise reducing glass would be a benefit? Is the window built in a way that will transfer as little noise as possible and are there options for noise reducing glass?