Has anyone seen a plenum rated water heater? I don’t think they exist.

[matt.mena]

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...

 

[Twowaxhack]

I have found heaters installed under AC units in the return air for years. In condos and apartments.

Never a problem. No it doesn’t meet current code. So what.......

New construction it’s not allowed here. And it’s enforced.

 

[matt.mena]

funny story...

On my wall rough inspection 2 years ago the inspector saw my normal State 10 gallon pre fabbed WH on the floor, not in the ceiling yet. He told me he would me for fail me for it. I asked Why? He Said it wasn’t plenum rated and I shall provide manufacturers specs that it’s plenum rated.

it’s not of course. I told my supervisor and I scheduled a site visit. I explained I could not provide any such document but hundreds of these have been installed and passed by your county. he said “unless you build floor to deck walls for a room and hang it there it technically doesn’t pass code”. I said, “no return air?” He said “cut a vent in the door”
I said “whoa, c’mon”

he said “cut off the plastic escutcheons and replace them with brass and I will pass it this time.”

I was blown away.
My other inspectors know he’s an idiot and we had a good laugh about that story yesterday, hence the question.

Good thing I don’t get his district much. I’m downtown now, he’s small commercial. My inspectors are 5+ story buildings. He’s known as the Idiot commercial inspector of my county, even by his coworkers. lol

I’ve never cut another escutcheon off one yet.
What you think about that? lol