By far, the vinyl replacement window is the most popular type of replacement window used to replace your home windows today. The reason for this is fairly straight forward. They (for the most part) are more affordable than wood, fiberglass or metal windows. They are also energy efficient and if installed properly, will provide years of maintenance free service. Keep in mind this is general information and is not intended to single out any manufacture or window brand.
Step One - Before getting into what to look for in a vinyl replacement window, you MUST make sure that new vinyl windows are the right product to use when replacing your current home windows. Most condo associations and historical societies have control over what home windows should be installed. Before contacting any contractors make sure your association or check to see if your home is located within a historical district will allow these types of home windows. If you checked this or the situation does not apply, move to step 2.
Step Two - You'll need to know what type of windows you currently have installed now. Not the style but type. Type is defined as material used to make the windows which are usually wood, metal or vinyl and is either a replacement or prime window.
While determining what material was used in manufacturing your current windows is straight forward, determining whether they are replacement or prime windows takes a little more skill. An example would be: If your current home windows are metal, and have a 3"- 8" sill inside surrounding entire home window, this would be a metal prime window. Many homeowners like to install window treatments in-between each side. Allowing the window treatment to operate within the opening which is level with the interior walls. Another example would be a totally wood window. This is considered a wood prime home window.
This is the most overlooked and misunderstood step when replacing your home windows. If your current windows are metal, the proper home window to install is new "vinyl prime windows" not the standard vinyl replacement window. Many homeowners and contractors shortcut this step by installing a standard vinyl replacement window simply because of price. While the price to install the correct window type may be higher, installing the wrong one can cost thousands of dollars in extensive damages later.
Standard vinyl replacement windows are designed as an insert for old wood windows with a frame that is in good shape. Unfortunately, many contractors have extended their use to replace prime windows. While this is a widely used practice by contractors, it is not supported by window manufactures and standard homeowners insurance does not cover for incompetent contractor mistakes. So the first rule in home window replacement is " if you remove a prime window, replace it with a prime window not a replacement window". The simplest way to understand what the difference between the types are is - Vinyl replacement home windows are installed from inside the home, vinyl replacement prime windows are installed from the outside.
Step Three - Now we can examine what to generally look for in the best vinyl replacement window to use for your home window replacement project.
Make sure the frame and sashes are welded not screwed together if your looking for longevity. Welded frames make the window stronger and keep the window square during installation. Mechanically fastened frames and sashes tend to loosen up over time due to window and building movement. This allows air infiltration.
Buy insulated glass: This is also known in the industry as an "IG" unit. Insulated glass is made up of two - three pieces of glass sealed on a spacer which acts as an insulator.
Depending what your weather are, purchasing a double pane IG unit will suffice. Although not recommended, Triple pane IG units will perform better energy wise, and is recommended for colder climates but makes for a very heavy home window unit. Vinyl replacement window frames and sashes are made of hollow chambered vinyl extrusions. Even though these extrusions are hollow, the chambered walls give the extrusion added strength. Once the window is assembled the dead air inside the sealed chambers act as an insulator.
To increase it's R-value, most vinyl window manufactures offer a foam filled option which increases the windows R-Value. Dense foam is inserted into the hollow chambers during the assembly of your new vinyl home windows. Low"E" glass has become very popular in recent years. The "E" stands for emissive. This coating is either spayed or roller applied to the inside of the outside piece of glass. This coating contains small metal fragments that reflect the suns ultraviolet rays away from the inside or your home. Low "E" glass is extremely effective for eliminating the fading of sun bleached furniture, wood floors and carpets.
Argon / Krypton Gas - these inert gases installed in-between a double or triple IG unit act as an invisible wall. Just like the foam filled frames, these gases increase the R-Value of the window. One thing to keep in mind though. These gases can only be installed if the Low"E" glass is used. The direct sun ultraviolet rays deteriorate the gases effectiveness.
Hardware - Always ask to see a window sample. Check out the hardware on the sample to see if it feels flimsy. Many manufactures are getting away from the old metal hardware, replacing with cheaper cast or even plastic hardware. If the hardware does appear flimsy, see if they can upgrade the hardware for you.
Screens - The one reason we buy windows is so that we can open them to get fresh air. Unfortunately, many homeowners overlook the screen. If you have cats that are not declawed, you may what to insist on metal instead of fiberglass screening. Also, some window styles such as double hungs and sliders come standard with 1/2 screens. Full screens should be an option if you want to open the top window and not the bottom. Most 1/2 screens are not designed to work in reverse.
Glass - Standard window glass is 1/8" thick, double strength glass is 1/4", extra strong glass is 1/4 " tempered glass. When choosing a house window ask about the glass. Today some major window manufactures provide windows with glass that cannot be replaced. Instead the entire sash needs to be replaced.
Research Your Windows - Once you get through all the items above, you'll need to do some research on the window you choose. First do a search on the manufacture and / or window model. Periodically homeowners post issues they have had with their home windows. You would be surprised on what you find. Next check the performance ratings for your prospective window(s) on the National Fenestration Rating Council® database. The web address is http://www.nfrc.org/windowshop/index.aspx. On their website you can research manufactures and / or window models.
There are two items you should compare.
First is the U-Factor - this represents the insulating factor of the window, the lower the U-Factor the better Second is the SHGC number - the lower the number the better the window. When comparing YOU MUST MAKE SURE THAT YOU USE THE CORRECT MODEL. Manufactures submit one unit for each product. Meaning they will submit one Double Hung window with out any options.
Then another with just Low "E" and yet another with Low"E" & Argon Gas and so on. Each being individually tested with the results listed for you to use and compare. When comparing properly you must compare windows with equal properties. Double Hung to Double Hung - Double Hung with Low'"E" Glass & Argon to Double Hung with Low'"E" Glass & Argon and so on...