Optimizing Building Design: Understanding and Managing Solar Heat Gain and Loss in the Pacific Northwest

By understanding the principles of solar heat gain and loss, architects can tailor their design choices to optimize thermal performance.

According to Green Building Advisor, in January Seattle averages -111 percent daily heat loss per square foot of glass.

In the pursuit of sustainable architecture and energy-efficient design, architects must prioritize the consideration of solar heat gain and loss. The impact of solar radiation on a building's thermal performance cannot be underestimated, as it directly affects occupant comfort and energy consumption.  

In the Pacific Northwest, where record highs dominate our summers, and cloud cover overshadows much of the upper left’s other seasons, it can be difficult to manage solar heat gains and losses in a consistent and energy efficient way.  Still, as architects and designers delve into the significance of understanding solar heat gain and loss, they can also explore various design strategies to mitigate their effects, such as tailored solutions to manage solar heat gains and losses effectively. By integrating custom window treatments into architectural designs, for example, architects can achieve harmonious synergy between form, function, and sustainability. 

Understanding Solar Heat Gain and Loss – A Refresher 

Solar heat gain refers to the process by which thermal energy from the sun penetrates a building's interior through windows and other openings. While natural light is very desirable for occupant well-being and aesthetics, there can be too much of a good thing, leading to overheating, unsafe UV, discomfort, and increased cooling loads. 

On the other hand, during colder months a building loses heat to the exterior. This heat loss phenomenon wastes energy, creates higher heating demands, and makes indoor spaces less comfortable. In cooling seasons, about 76 percent of sunlight that falls on standard double-pane windows enters to become interior heat. 

To optimize a building's energy performance, architects must strike a balance between controlling solar heat gain during hot seasons and minimizing heat loss during colder periods.  

Take the example of two major cities in the Pacific Northwest – Seattle, WA and Portland, OR respectively. According to Green Building Advisor, in January Seattle averages -111 percent daily heat loss per square foot of glass. Portland averages -115. Neither city can depend on wintertime sun to provide solar heating. Yet, peaks in solar heat gain during hotter months must be mitigated.  

This balance can be achieved by implementing design strategies that integrate holistic solutions for managing solar heat gains and losses. Custom window treatments are one large piece of that puzzle. 

Integrating Custom Window Treatments – A Practical Approach  

Custom window treatments offer architects an array of innovative solutions to address solar heat gain and loss. By tailoring these treatments to specific building requirements, architects can optimize their design and specification choices. Consider two examples of products A&I manufactures right here in the Pacific Northwest: cell shades and roller shades. 

The unique hexagonal cell structure of cell (or, “honeycomb”) shades, for example, traps air; a design element that enhances their insulating properties, making them an excellent choice for managing solar heat gain and loss. The air pockets within cellular shades act as a buffer against temperature fluctuations, reducing the transfer of heat through windows. 

Then, too, there are roller shades.  

In the context of sustainable architecture and energy-efficient design, roller shades contribute to the harmonious balance between form, function, and sustainability. Their unique design allows for customization and optimization based on specific building requirements.  

For instance, roller shades can be manufactured with fabrics that have high solar reflectance properties to minimize solar heat gain during hot seasons. This helps reduce the amount of heat transmitted through windows, leading to improved energy efficiency and enhanced occupant comfort. Additionally, roller shades can be designed with insulating properties by incorporating thermal backing or specialized fabrics. This feature helps to reduce heat loss during colder months, thereby minimizing energy waste and maintaining comfortable indoor environments. By utilizing roller shades with insulating properties, architects can mitigate the negative impact of solar heat gain and loss, leading to more sustainable and energy-efficient building designs. 

Design Considerations and Strategies 

When considering the use of custom window treatments, think of how their strategic use moves them from a line item on a spec sheet into an amazing tool that contributes to the health and comfort of the built environment.  

Most window coverings open and close by degree, and yet 75 percent of residential window coverings remain in the same position every day, according to a study by the U.S. Department of Energy. Integrating automation and smart control systems enables dynamic adjustment of custom window treatments based on real-time data. Sensors can detect solar intensity, temperature, and occupancy to optimize the position or openness of window treatments helping to maintain a comfortable indoor environment thus minimizing energy consumption while allowing optimal light for occupants.   

Integrating custom window treatments into architectural design is a powerful strategy for controlling solar heat gain and loss, resulting in enhanced energy efficiency and occupant comfort. By understanding the principles of solar heat gain and loss, architects can tailor their design choices to optimize thermal performance. Custom window treatments offer versatile solutions to manage solar heat gains and losses effectively, helping architects and designers enhance their sustainable and energy-efficient buildings for a greener future. 

To learn more about how A&I Manufacturing is working to help architects optimize building design by using sustainable, energy-efficient, locally made products, visit our Motorized and For Architects pages.