How can the visible transmittance rating be used in energy-efficient design?

The visible transmittance rating (VT) can be used in energy-efficient design to maximize natural light utilization and reduce the need for artificial lighting, thus saving energy. Here are a few ways it can be utilized:

1. Daylighting: By selecting building materials, such as windows or skylights, with high VT ratings, designers can allow more natural light into the building. This reduces the reliance on electric lighting during daylight hours, resulting in energy savings.

2. Lighting Controls: VT ratings can help determine the appropriate light control strategies for a space. Spaces with high VT ratings can benefit from daylight-responsive lighting controls, such as sensors that adjust artificial lighting levels based on the available daylight. This helps maintain desired light levels while minimizing energy consumption.

3. Glazing Selection: Using glazing materials with high VT ratings for windows and facades can optimize energy efficiency. These materials allow ample natural light to enter the building while reducing the heat gain from direct sunlight, known as solar heat gain coefficient (SHGC). The combination of high VT and low SHGC can help optimize the energy performance of the building.

4. Designing for Visual Comfort: VT ratings also contribute to visual comfort and occupant satisfaction. High-quality natural light improves visual clarity, reduces glare, and creates a connection with the outdoor environment. This, in turn, enhances occupant well-being and productivity.

By factoring in VT ratings at the design stage, architects and designers can incorporate energy-efficient strategies that promote the efficient use of natural light, reduce reliance on artificial lighting, and improve overall energy performance.

Publication date: