Fire Performance and Environmental Impact Evaluations of Communication Cable Installations with Unexpected Infrastructure Fire-Safety Implications

摘要

Changing environmental interests in the wire and cable industry(WCI) have generated studies into the eco-performance of variousdata and communication cabling system alternatives forcomputers and local area networks (LAN). To accurately assessthe various alternatives, the installed electronic functionality andfire safety performance requirements of the various end-useproduct options must be equivalent. In buildings, high fireperformance (HFP) based polyvinyl chloride (PVC) sheathed andperfluoropolymer (PFP) insulated (CMP or PVC/PFP) cables canbe routed directly in concealed plenum spaces without the use ofadditional metal conduit fire protection. Products that do notmeet specific high fire-performance criteria, such as low-smokezero-halogen (LSZH/PE) cables or riser-rated cables (CMR orPVC/PE), often must be protected inside other structures,typically metal EMT conduit or trunking. Life cycle analysis(LCA) via ISO 14040 methodology is used to evaluate cablingalternatives using an appropriate functional unit. Copper wire isidentified as a significant contributor to all impact categories, andthe major contributor for human toxicity. The burdens for steelconduits dominate all other impact categories studied for systemsrequiring steel for fire performance code compliance. Theadditional fire safety and installation advantages provided by theCMP cables offset the environmental burdens associated with theinitial manufacture of just the cable. Thus, CMP cables providesuperior overall fire safety, environmental performance, andeconomic benefits versus LSZH/PE and CMR cables installed inmetal conduits for U.S. plenum cable installations. During thewriting of this paper, new fire safety research became availableindicating that EMT die cast conduit-couplings can begin toweaken, melt and fail to fire-protect in less than 4 minutes at orless than 400°C (images to be shown). This finding is notconsistent with previous beliefs that the fire performance of CMRor LSZH cable in EMT conduit was equal to the performance ofCMP cable.