A Guide To Natural Ventilation For Windows And Skylights In Different Climates

As the seasons change, and homeowners increasingly prioritize sustainability and cost-efficiency, natural ventilation emerges as a crucial element in home design. To gain expert insights into this vital aspect of design, we spoke with Kolbe Windows and Doors, Marvin, Pella Windows and Doors and VELUX Skylights  on how to optimize natural ventilation across diverse climates.

High and Low Placement of Windows Provides Optimal Airflow

Pella: Venting skylights, clerestory windows and transom windows placed high on a wall or ceiling allow hot air to escape from a high point in the room. Pairing those with windows placed lower in the room allows cool air to enter through a lower point and create a natural circulation of air.

Opposite Walls Promote Natural Cross-Ventilation

VELUX: Skylights and windows installed on opposite walls make up the best configuration to promote natural cross-ventilation. If opposite walls are not feasible, installing them on adjacent walls can still facilitate good airflow.

Kolbe: As the name suggests, cross-ventilation is achieved by placing windows in opposing locations to achieve air movement across the bulk of an interior space. Since in the United States, wind generally blows from the west to east, it is most effective to install venting window units on the east and west exterior walls.

Utilize Double-Hung and Clerestory Windows for Ventilation

Pella: Natural air circulation can also be encouraged with double-hung windows because both the upper and lower sash can be vented.

Kolbe: For additional air movement, there is another technique called “stacking.” Stacking uses a lower window opening to welcome in cooler air and an upper window opening to allow out rising hot air and moisture. Simply opening both sashes on a double hung window can create this effect locally. On a greater scale, stacking can also be achieved in a double-heighted space with the help of specialized fenestration like clerestory windows.

Window Orientation Affects Solar Heat Gain

VELUX: When it comes to orientation and placement, opt for north-facing windows and skylights. Windows and skylights that face north provide consistent, cool illumination with minimal heat gain. For existing south-facing windows, overhangs or awnings can be installed to block high summer sun while still allowing in sunlight during the winter. East- and west-facing windows and skylights, on the other hand, can cause significant heat gain in the mornings and afternoons, making cooling more challenging.

1. Natural Ventilation Supports Sustainability and Energy Efficiency

Pella: Natural ventilation is a primary component of sustainable projects. If included at the beginning of a project, when factors such as topography, positioning and infrastructure are being considered, it is a way for a builder or architect to minimize wasteful energy consumption. They can initiate better practices and potentially better energy sources.

With incentivized programs, like becoming more utilized by builders, and considerations around air exchange rates becoming more prevalent, more homeowners may want to have conversations around ventilation in their home.

VELUX: Incorporating natural ventilation into building projects is crucial. It enhances energy efficiency by reducing the reliance on mechanical systems (like air conditioning), leading to significant energy savings and a lower carbon footprint.

2. Indoor Air Quality Improves

Kolbe: Natural ventilation helps improve the air quality of an interior space. Many homes today are designed to be airtight, which could result in stagnant, damp air. In some instances, natural ventilation can even help alleviate symptoms associated with specific health conditions, like asthma.

3. It Enhances Thermal Comfort & Lowers Maintenance Cost

VELUX: Natural ventilation contributes to thermal comfort by utilizing wind and thermal buoyancy to maintain a comfortable indoor temperature, reducing the need for constant mechanical cooling and heating. Moreover, buildings designed with natural ventilation typically have lower construction and maintenance costs compared to those heavily reliant on mechanical systems, due to the reduced need for complex HVAC systems.

Window and Skylight Orientation and Placement Impact Solar Heat Amount

Our manufacturer interviewees agree that maximizing south-facing windows (north-facing in the Southern Hemisphere) is crucial for capturing optimal sunlight and passive solar heat gain. They emphasize the importance of well-insulated windows and skylights, strategic placement for ventilation and the use of shading systems to control solar gain and optimize energy efficiency.

Automated and Smart Technology Will Play a Big Role

Marvin: With homeowners continuing to seek indoor-outdoor connections, windows and doors that incorporate technology to enhance this connection are becoming increasingly popular. Innovations such as  and energy efficiency in homes by offering features that can automatically open windows and doors based on indoor air quality or outdoor conditions. This also allows homeowners to open windows that would have otherwise been out of reach.

Pella: Access to light and fresh air is imperative in all window and door development and that is unlikely to change. However, considerations around how someone gains access to fresh air is an opportunity for innovation.

Another opportunity for innovation is the syncing of blinds, shades and/or windows to open and close with the sun or according to the weather. Windows and doors help homes breathe and will continue to push our industry to answer our customers’ needs better.

VELUX: Smart home technology is already available that opens and closes windows and skylights based on the preferred indoor climate settings. Additionally, there are several innovations in skylight and window tech that are poised to significantly enhance natural ventilation and energy efficiency across various climates.

One promising development is smart window technology, which allows glass windows to adjust their properties based on environmental conditions, such as changing their tint to control the amount of sunlight entering a room. Some smart windows also incorporate solar cell technology, allowing them to harvest solar energy and convert it to electricity.

Another innovation is the use of dynamic facades and advanced glazing systems that can react and self-regulate according to environmental inputs, such as adjusting to optimize solar gain in the winter and provide passing cooling in the summer. Aerogel coatings, which provide excellent insulation by blocking heat transfer without compromising clarity, are also making strides in window and skylight technology.

Lastly, photovoltaic windows that use materials like perovskite are being developed to convert sunlight into electricity without darkening the view. This would allow both windows and skylights to serve as a source of natural light and a means of generating renewable energy.

Kolbe: Broadly speaking, as overall fenestration design continues to improve in its reliability of performance, ease of use and depth of customization, it will be more attractive for the standard home to implement venting windows and other glass openings. Windows are sometimes seen as the “weak point” of a building’s façade, but with improved insulating materials and new glass technologies gaining traction every day, that impression may disappear. Then, end users will be more willing to add windows to a space and organically create natural ventilation.

By harnessing the power of natural airflow and strategically utilizing windows and skylights, builders, designers and architects can create healthier, more comfortable and energy-efficient living spaces. To partner with a trusted manufacturer and bring your vision to life, visit https://www.openuptoperformance.com/manufacturers/.