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Safety of PVC exhaust pipes on 90% efficient furnace

D4xo4UCW53 | Posted in Energy Efficiency and Durability on

Have there been any studies or are there any known or suspected problems or concerns on the safety of the PVC exhaust systems on these 90% efficiency furnaces with respect to off-gassing and it’s effect on the quality of air in the home. Thanks.

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  1. Riversong | | #1

    PVC (vinyl) is one of the most common synthetic materials in all manner of consumer products, and it has profound negative environmental impacts at both the front end and back end of its lifecycle, primarily from dioxin release (viz Agent Orange, which poisoned tens of thousands of US G.I.s in Vietnam).

    The human health effects during use are mostly from additives to PVC, including pthalates and cadmium. But the working side of intake and exhaust vents for sealed-combustion, direct-vent appliances are isolated from the indoor environment and should have no impact on indoor air quality. Exhaust temperatures are low, but the exhaust gases are wet and acidic, so plastic vents are the most appropriate.

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