Fitwel Standard Reinforces Integrated Building Health
The Fitwel v2.1 Indoor Air Quality Standard underscores the industry's move toward holistic, evidence-based building wellness. While not focused on lighting, its emphasis on aligning systems to meet rigorous air quality and ventilation metrics reinforces the need for integrated design. This expectation requires lighting professionals to specify products not in isolation, but as part of a comprehensive strategy for occupant health.
- The WELL Building Standard v2, a parallel certification focused on human health, quantifies circadian lighting performance using Equivalent Melanopic Lux (EML), a metric that measures light's impact on our biological clocks. To achieve the circadian lighting design feature, WELL requires providing at least 150 EML for a minimum of four hours per day, a target that can be met through a combination of daylight and electric light. - Fitwel's latest version (v3), released in June 2024, updated its lighting requirements to include more pathways for demonstrating daylight access through simulations and added specific criteria for minimizing glare and light pollution. For optimal lighting, it specifies that luminaires should have a Unified Glare Rating (UGR) of 19 or lower and controls must be low-flicker, aligning with standards like California Title 24. - Integration with building automation is often achieved using the DALI-2 protocol, an open standard that ensures interoperability between control devices like sensors and application controllers from different manufacturers. This allows lighting to be seamlessly managed as part of a larger building management system, coordinating with HVAC and other services. - The push for healthier buildings extends to planetary health through the circular economy, a concept gaining traction in the lighting industry to minimize waste by designing for durability, modularity, and repairability. Companies like Signify are developing serviceable luminaires and circular components, with innovations like 3D-printed fixtures that can have a 75% lower carbon footprint than conventional metal ones. - While seemingly separate, lighting can directly impact indoor air quality; for example, the heat generated by inefficient lighting can alter HVAC system loads and airflow. Furthermore, emerging technologies like Far-UVC lighting, used for disinfection, can generate ozone and other secondary pollutants, requiring careful consideration of ventilation and lamp placement. - The non-visual effects of light are measured by how they stimulate intrinsically photosensitive Retinal Ganglion Cells (ipRGCs), which contain melanopsin and regulate the circadian system. These cells are most sensitive to blue-green light, which is why metrics like EML are weighted differently than traditional visual lux, which peaks in the yellow-green part of the spectrum.
