Your typical electric metal water heaters installed within a plenum ceiling do not meet code. Yet no one notices. *This is drawn by architects normally in office buildings. The county always red stamps the submitted drawings, approved for installation.”
Everything within a plenum ceiling must meet fire & HVAC codes which are in place to keep occupants inside the building safe from inhaling poisonous smoke distributed by a plenum air return. Codes which strictly limit what is allowed to be installed within a plenum ceiling. PVC is not allowed within a plenum area or ceiling. The material has been tested by a third party to withstand heat to a certain degree & smoke with low toxicity. Then it’s plenum rated PVC.
The PVC insulation of electric wire does not meet fire standards & has a very poisonous smoke. It must be wrapped or contained within a metal NEC approved product. Metal 4 squares, conduits, BX cable, etc. *Wires can be wrapped with plenum rated PVC jacket, used mainly by low voltage systems.*
The metal casing of a typical water heater is not approved to house typical wires. The inlet/outlet PVC escutcheons are standard, not allowed. Water heaters that I’ve seen are not manufactured with plenum codes in mind.
I know electric water heaters are safe within a plenum ceiling. We install by drawings like this all the time, usually on a square suspended Holdrite pan. It’s safe, just not legal.
Anyway, Have you seen a water heater rated for a plenum ceiling? Whoever patents one and brings up this case will be a millionaire. If I only had the time...
Everything within a plenum ceiling must meet fire & HVAC codes which are in place to keep occupants inside the building safe from inhaling poisonous smoke distributed by a plenum air return. Codes which strictly limit what is allowed to be installed within a plenum ceiling. PVC is not allowed within a plenum area or ceiling. The material has been tested by a third party to withstand heat to a certain degree & smoke with low toxicity. Then it’s plenum rated PVC.
The PVC insulation of electric wire does not meet fire standards & has a very poisonous smoke. It must be wrapped or contained within a metal NEC approved product. Metal 4 squares, conduits, BX cable, etc. *Wires can be wrapped with plenum rated PVC jacket, used mainly by low voltage systems.*
The metal casing of a typical water heater is not approved to house typical wires. The inlet/outlet PVC escutcheons are standard, not allowed. Water heaters that I’ve seen are not manufactured with plenum codes in mind.
I know electric water heaters are safe within a plenum ceiling. We install by drawings like this all the time, usually on a square suspended Holdrite pan. It’s safe, just not legal.
Anyway, Have you seen a water heater rated for a plenum ceiling? Whoever patents one and brings up this case will be a millionaire. If I only had the time...
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