Sliding Windows: Everything You Need to Know
Many homeowners mistakenly believe that window design can allow for fresh air or natural light to infiltrate their homes. Large bay windows in living rooms often open the house up to the surrounding landscape, a central part of biophilic design. However, the sheer size of those windows often makes it possible for them to be opened to allow fresh summer breezes to cool the home naturally. On the flip side, smaller windows strategically oriented to capture prevailing winds can be easily be opened and closed. These windows play a major role in natural home ventilation and help homeowners drastically reduce their summer air conditioning bills.
Might there be a way to combine the natural light-enhancing qualities of large windows with the natural ventilation properties of smaller windows that can be opened and closed? Sliding windows, also referred to as "slider windows," often allow the best of both worlds. These products can be easily opened and closed to help homeowners bring in fresh air to refresh their homes. Sliding windows often also allow for more natural light penetration into the house.
Below, we take an in-depth look at what to look for in the best sliding windows and why you should consider one of these windows for your home.
What Is a Sliding Window?
Sliding windows are an ideal option for homeowners wanting to maximize picturesque views and natural lighting without sacrificing the benefits of fresh airflow. Sliding windows, as their name implies, have a horizontal opening style. Because most windows open vertically, the weight of the window limits the overall size. However, due to their horizontal opening, sliding windows can be significantly larger while still making it easy to let the fresh air into your home.
Sliding windows can also be used in other situations. For example, they can allow for a small opening or inlet for fresh air in tight areas of your home where you may not have the leverage required for a hung window. Small bathrooms or tight areas near a kitchen sink are a few areas where smaller sliding windows can be strategically placed to maximize fresh air.
The most appreciated advantage of sliding windows is that they are ideal for large rooms. Whereas most fixed window styles incorporate separate panes, sliding windows are perfect for framing an enchanting view because of the unhindered view they provide. On the downside, however, sliding windows are generally less energy-efficient than other window types. The United States Department of Energy (DOE) states that "single and double sash sliding windows generally have higher air leakage rates than projecting or hinged windows."
What Types of Sliding Windows Are Available?
Sliding windows operate with a simple design that incorporates two or more sashes within a single frame. The window opens horizontally on those sashes. Most sliding windows only have one moving pane while the other is fixed in the frame.
There are window manufacturers, however, who design sliding windows with two or three movable sashes. This feature can come in handy if you want to maximize the airflow within your home. It can also make cleaning and maintenance more straightforward as you can easily access both sides of the window pane from the interior of your home.
Homeowners can most often find sliding windows 36, 48, 60, 72, and 84 inches wide, and either 24, 36, 48, and 60 inches high. Many custom home builders can also make custom-sized sliding windows to fit virtually any size. Of course, sliding windows come with all different types of glass, glazing, and framing. Vinyl, wood, fiberglass, or architectural grade window frames can all be designed to work with sliding windows. The same goes for the different types of window glazing. Check out this Rise guide on what to look for in the most energy-efficient windows, no matter what style of window you choose.
Are Sliding Windows Energy-Efficient?
In general, sliding windows are less energy efficient than the more commonly installed casement window products on the market. The overlapping sashes can lead to air leaks, thus compromising the airtightness of the building envelope. Also, the constant opening and closing can wear down the weather stripping more quickly, further aggravating air leak problems.
Proper maintenance to sliding windows, however, can reduce the likelihood of severe air leaks. Also, opting for triple-pane glazing and low emissivity (Low-E) glass can drastically increase every window type's energy efficiency and thermal performance.
In general, sliding windows are most "energy-appropriate" in climates where maximizing natural ventilation and natural cooling strategies can significantly reduce your air conditioning bills in the summer. In areas with cold winters and mild summers, however, the tendency towards air leaks might make sliding windows more of an energy-efficiency casualty.
How Long Do Sliding Windows Last?
Like other window types, high-quality sliding windows should last you anywhere between 15 and 20 years before you need to start to think about replacement. The durability of sliding windows is mainly related to the framing you choose. Vinyl and PVC window frames are generally the most durable frames (up to 40 years). However, they are made from petrochemicals and come with a high embodied energy footprint. Aluminum, fiberglass, and wood frames for sliding windows should last for at least 20 years.
Are Sliding Windows Easy to Maintain?
One of the challenges that come with sliding windows (or any fixed window) is that the exterior side of the windows is generally more challenging to clean. You will most likely need to clean single-sash sliding windows from the outside. For second-story windows without a balcony, this might entail trying to stay balanced on a 20-foot ladder while spraying Windex.
However, double or triple sash sliding windows make it easy for homeowners to slide open one side of the window to clean the other two exterior sides. This feature can come in handy for windows in elevated areas with no easy external access for regular cleaning. You will also need to regularly remove dust, debris, and other objects that might fall between the sliding rails. Without regular cleaning of the rails, sliding windows are prone to stick and may not open or close correctly.
In terms of maintenance, sliding windows will most likely need a re-application of weather stripping more often than casement-style windows. Due to the constant opening and closing, the weather stripping on these windows is prone to wearing down more quickly.
How Do You Install Sliding Windows?
Sliding windows can be installed as a replacement for any window type. To avoid making changes to your house framing, you must find a sliding window with the exact dimensions of the window you are replacing. It is best to get a professional to size the window to ensure a perfect fit. Once you have removed the old window:
- Add sufficient caulking around the frame, and use shims around the frame to ensure that the new sliding window is plumb and level.
- Secure the window frame to the window opening before situating the sliding windows into the frame.
- You may need to adjust the tension on the rails to make sure they do not stick.
- Add weather stripping around the window.
You can find a complete video tutorial on installing sliding windows here.
What Are The Best Brands of Sliding Windows?
Sliding windows are growing in popularity with homeowners, especially among those who live in warmer climates where summer breezes' cooling effect can help reduce A/C energy usage. Today, several brands are selling high-quality sliding windows.
Andersen Windows
Andersen Windows sells several types of horizontal sliding windows that they call "Glider Windows." Their 400 Series of Glider Windows are an excellent choice for rooms that face walkways, porches, or decks as both sashes glide horizontally for maximum ventilation. Made of wood protected by a vinyl exterior, it is the company's best-selling gliding window. Andersen's gliding windows come in standard sizes up to 6'6' wide and 5'5' high.
Champion Window
Champion Window offers some of the best energy-efficiency features in its sliding window products. Their Comfort 365® Glass features Low-E (low emissivity) coating combined with an argon gas fill between the panes. The glass in these windows is said to block 95 percent of harmful UV rays and keeps heat in during the winter and out during the summer.
Wincore Windows LLC
Wincore Windows also offers high-quality sliding windows. The company's 700 Series double sliding windows have an operating unit with both sash opening and closing from side to side. The insulating glass unit is 3/4" thick and features standard Low-E coating with Argon gas. The U-channel spacer enhances energy efficiency by forcing temperature currents to travel in an indirect path, thus weakening their strength.
You can find a complete list of ENERGY STAR certified horizontal sliding windows here.
What Are The Pros of Sliding Windows?
Sliding windows offer both advantages and disadvantages that every homeowner needs to consider. On the plus side, sliding windows can allow homeowners to maximize natural ventilation in their homes. In some climates, strategically placed sliding windows may let you turn off your air conditioner in the summer evenings and nights to allow pleasant breezes to cool your home naturally. Also, sliding windows can enable large, uninterrupted openings to get the most out of natural lighting schemes and biophilic design setups. Sliding windows are also often made with built-in child latches that are not standard with other window types.
What Are The Cons of Sliding Windows?
On the downside, sliding windows are generally less energy-efficient than their casement window counterparts. Due to the complicated rails and sashes, they also are more prone to air leaks. Single sash sliding windows may cause difficulty when it comes to cleaning the glass's exterior.
Article by:
Tobias Roberts
Tobias runs an agroecology farm and a natural building collective in the mountains of El Salvador. He specializes in earthen construction methods and uses permaculture design methods to integrate structures into the sustainability of the landscape.