The sash is the movable or fixed frame that holds the glass panes within a window. In operable windows, such as single-hung or double-hung styles, the sash allows for the opening and closing of the window. It is an integral component that ensures the glass is securely held in place while providing the functionality of movement.
In double-hung windows, there are typically two sashes: an upper and a lower one, both of which can move vertically. In single-hung windows, only the lower sash is operable, while the upper sash remains fixed. The design and condition of the sash significantly impact the window’s performance, including its ease of operation, energy efficiency, and security.
A double-hung window features two vertically sliding sashes within a single frame. Both the upper and lower sashes can move up and down, allowing for versatile ventilation options. This design facilitates easy cleaning, as both sashes can tilt inward, making it convenient to clean the exterior glass from inside the home.
Double-hung windows are prevalent in various architectural styles due to their classic appearance and functional benefits. They are especially suitable for rooms facing walkways or patios, as they do not protrude outward when opened. The ability to open both sashes enhances airflow and can aid in regulating indoor temperatures.
A single-hung window resembles a double-hung window in appearance but differs in functionality. In this design, only the lower sash is operable, moving vertically to open and close, while the upper sash remains fixed. This configuration offers a cost-effective solution with fewer moving parts, potentially reducing maintenance needs.
Single-hung windows are commonly used in residential settings, particularly in areas where the upper sash’s immobility is not a concern. They provide reliable security and energy efficiency, as the fixed upper sash can offer better insulation. However, cleaning the exterior of the upper sash may require access from outside the building.
A casement window is hinged on one side and opens outward like a door, operated by a crank mechanism. This design allows for full top-to-bottom ventilation and provides an unobstructed view. Casement windows are known for their energy efficiency, as the sash presses firmly against the frame when closed, creating an airtight seal.
Casement windows are versatile and can be used singly or in pairs within a common frame. They are particularly suitable for hard-to-reach areas, such as over kitchen sinks, due to the ease of operation. Regular maintenance of the hinges and crank mechanism ensures smooth functioning over time.
A double pane Insulated Glass Unit (IGU) consists of two glass panes separated by a spacer and sealed to create an insulating air space. This design enhances thermal performance by reducing heat transfer, thereby improving energy efficiency and comfort within the home. The sealed air space can also be filled with inert gases like argon for additional insulation.
The double pane IGU minimizes condensation and noise infiltration, making it a popular choice for modern windows. The durability and effectiveness of the seal are crucial for maintaining the unit’s insulating properties over time. Proper installation and quality materials ensure the longevity and performance of double pane IGUs.
Another type of IGU is a Triple Pane with three layers of glass.
Tempered glass is a type of safety glass processed through controlled thermal or chemical treatments to increase its strength compared to standard glass. When broken, it shatters into small, blunt pieces, reducing the risk of injury. This property makes it suitable for areas where human safety is a concern, such as doors, shower enclosures, and windows near floor level.
The manufacturing process involves heating the glass to high temperatures and then rapidly cooling it, creating internal stresses that enhance its strength. Tempered glass is often required by building codes in specific applications due to its safety features. It is also more resistant to thermal stress and impact than regular annealed glass.
Laminated glass comprises two or more layers of glass bonded together with an interlayer, typically made of polyvinyl butyral (PVB). This construction holds the glass layers together upon impact, preventing them from shattering into large, sharp pieces. Laminated glass is commonly used for its safety, security, and sound insulation properties.
Its sound-dampening qualities make it ideal for use in noisy environments. Laminated glass is often utilized in skylights, hurricane-resistant windows, and areas requiring heightened security.
A pivot pin is a small metal component that connects the window sash to the balance system, allowing the sash to pivot during opening and closing. In tilt windows, the pivot pin enables the sash to tilt inward for easy cleaning and maintenance. Proper functioning of the pivot pin is essential for the smooth operation of the window.
Over time, pivot pins can wear out or become damaged, leading to difficulties in tilting or operating the sash. Replacing a faulty pivot pin is a relatively straightforward repair that can restore the window’s functionality. Regular inspection and maintenance of pivot pins help ensure the longevity of tilt windows.
A spiral balance is a type of window balance system that uses a spiral-shaped rod to counterbalance the weight of the sash, facilitating smooth opening and closing. This mechanism is commonly found in double-hung and single-hung windows. The spiral balance is enclosed within a tube and connected to the sash via a pivot shoe.
Over time, spiral balances may lose tension or become worn, affecting the window’s operability. Adjusting or replacing the spiral balance can restore proper function. Regular maintenance ensures the balance system continues to support the sash effectively, preventing issues such as sash drooping or difficulty in operation.
A coil balance, also known as a constant force balance, utilizes a flat, coiled spring to counterbalance the sash’s weight. This system provides consistent tension throughout the sash’s movement, ensuring smooth operation. Coil balances are compact and often used in modern window designs for their reliability and ease of installation.
The coil balance is typically housed within a balance shoe and connected to the sash. If the coil loses tension or breaks, the sash may become difficult to operate or fail to stay open. Replacing the coil balance is a common repair that can restore the window’s functionality. Regular inspection helps identify issues before they lead to more significant problems.
A block and tackle balance system combines pulleys (blocks) and cords (tackle) to counterbalance the window sash’s weight. This mechanism allows for smooth and controlled movement of the sash, commonly found in double-hung windows. The system is concealed within the window frame, contributing to a clean aesthetic.
Over time, components of the block and tackle balance, such as cords or pulleys, may wear out or break, leading to operational issues. Maintenance or replacement of the balance system can restore the window’s ease of use. Regular checks can help detect wear early, preventing more extensive repairs.
A block and tackle balance system combines pulleys (blocks) and cords (tackle) to counterbalance the window sash’s weight. This mechanism allows for smooth and controlled movement of the sash, commonly found in double-hung windows. The system is concealed within the window frame, contributing to a clean aesthetic.
Over time, components of the block and tackle balance, such as cords or pulleys, may wear out or break, leading to operational issues. Maintenance or replacement of the balance system can restore the window’s ease of use. Regular checks can help detect wear early, preventing more extensive repairs.
Low-E (low-emissivity) glass features a microscopically thin coating that reflects infrared energy (heat) while allowing visible light to pass through. This property helps keep indoor spaces warmer in the winter and cooler in the summer, enhancing energy efficiency. Low-E coatings also reduce UV radiation, minimizing fading of interior furnishings.
When it comes to improving the energy efficiency of modern windows, inert gas fillsplay a crucial role. Gases like argon, krypton, and xenon are inserted between the panes of double- or triple-pane windows to reduce heat transfer and improve insulation. These gases are colorless, odorless, and non-toxic, and they act as an invisible barrier that slows the movement of heat and cold through the glass. By replacing the air in the sealed space between panes, inert gases significantly enhance the window’s R-value, which measures thermal resistance.
Argon gas is the most commonly used due to its excellent insulating properties and affordability. It makes up less than 1% of the Earth’s atmosphere and has a thermal conductivity about 67% lower than air, which helps keep warm air inside during winter and hot air out during summer. Krypton, though more expensive, is even more effective in smaller spaces between panes, often found in higher-end or triple-pane windows. Xenonoffers the best insulation of the three but is rarely used in residential applications due to its high cost. For homeowners looking to reduce energy bills and increase indoor comfort, windows filled with inert gas are a smart, long-term investment.
The Glassman is Columbus’s go-to expert for high-quality residential and commercial glass repair, installation, and custom designs. With over 60 years of experience, we deliver precision craftsmanship and top-tier service you can trust.
