Co-formed Plenum Reflector for Troffer Light Fixtures
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Solution Overview
Problem
Traditional troffer-style light fixtures face challenges in cost reduction and compatibility with plenum ceiling environments, where mechanical components must meet stringent fire and smoke propagation standards to ensure safety and compliance with NFPA regulations.
Innovation Solution
A co-formed reflector made from plenum-rated plastic and a diffuse white reflective material, combined with a heatsink and lens assembly, allows for a cost-effective and larger fixture design that meets plenum ceiling requirements, using coextrusion or other forming methods to integrate structural and optical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional metal troffers are used, then structural strength and fire resistance are ensured, but manufacturing cost increases and fixture size is limited
Solution Approach 1:
The patent applies composite materials by combining plenum-rated plastic substrate with reflective material through coextrusion to form the reflector component. This composite structure achieves both the fire resistance and smoke propagation compliance required for plenum ceilings while reducing manufacturing cost compared to traditional metal troffers. The composite material enables larger fixture dimensions without proportionally increasing cost.
2Reliability
If plenum-rated materials are used, then compliance with NFPA smoke propagation standards is achieved, but material selection and manufacturing complexity increase
Solution Approach 1:
The patent merges multiple functions into a single coextruded component. The plenum-rated plastic substrate is coextruded with the reflective material to create an integrated reflector that simultaneously provides structural support, optical reflection, and fire/smoke compliance. This consolidation reduces manufacturing complexity compared to assembling separate components, as the multi-functional element is produced in one extrusion process.
Solution Approach 2:
The coextruded reflector serves multiple functions: it provides the reflective surface for light distribution, maintains structural integrity of the fixture, and ensures compliance with NFPA plenum standards. This multi-functionality reduces the number of separate components needed, simplifying both manufacturing and assembly processes while maintaining reliability.
3Area of stationary object
If fixture size is increased, then light output and coverage area improve, but material cost and manufacturing difficulty increase
Solution Approach 1:
The patent utilizes parameter changes in the coextrusion process to produce the reflector with varying material compositions and thicknesses in different zones. This allows optimization of material usage - thicker plenum-rated material where structural integrity and fire resistance are critical, and thinner or optimized reflective material where light distribution is the primary function. This parameter variation enables larger fixture sizes without linearly increasing material cost.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables the creation of a lower-cost, larger troffer-style light fixture suitable for plenum ceiling applications while ensuring compliance with NFPA standards, enhancing optical efficiency and safety by using plenum-rated materials that pass stringent smoke propagation tests.
Implementation Method 1
a co-formed reflector made from plenum-rated plastic and a diffuse white reflective material, combined with a heatsink and lens assembly, allows for a cost-effective and larger fixture design that meets plenum ceiling requirements
Data Source
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AI summary
A light fixture with co-formed plenum component is disclosed. Embodiments of the invention provide troffer-style recessed solid state fixture (100, 700) using a highly reflective plastic reflector (108, 701, 702). In at least some embodiments, the plastic reflector (108, 701, 702) can meet the additional requirements placed on mechanical components exposed to the space above the ceiling plane in plenum return ceiling applications. Example embodiments include a light fixture (100, 700) with an LED light source and a reflector (108, 701, 702) that is coextruded from a plenum rated substrate and a reflective material (402, 404), for example, a plenum rated plastic substrate and a diffuse, white reflective material (402, 404). In some embodiments, the plenum rated substrate includes polyetherimide, a polyphenylene ether/polystyrene blend, polycarbonate, polycarbonate copolymer, or a combination of the foregoing.