[RE-wrenches] My AHJ insisting on "Flammable Vapor Ignition Resistant" 18-inch requirement

Thu Sep 11 15:06:50 PDT 2025

Awesome! I'm glad it helped.

By the way, I just published my article on protecting ESS from vehicular
traffic here:
https://floridasolardesigngroup.com/protecting-home-batteries-from-vehicle-impact

The IFC already has guidance with a reasonable framework. The Florida
Building Code is about to adopt it. I had to dig DEEP to find the code
committee amendment on this. I will admit - ChatGPT's Agent Mode with a
Plus subscription pointed me in the right direction.

The real key takeaway is that the code is trying to protect ESS from the
**normal path** of vehicular traffic, not to prevent all calamities.

Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956
Florida Certified Electrical Contractor EC13013208

On Thu, Sep 11, 2025 at 5:13 PM scot.arey--- via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Jason's well-laid arguments won the day here. Very much the logic you laid
> out and the AHJ reluctantly conceded the point.
>
> He tried going directly to Mechanical Code but I said no, pertinent
> sections of IMC are in IRC, Ch 12-24. Then he tried saying that IFC had
> more stringent requirements that R330 (ESS) but I said, no you won't find
> any reference to 18" in the ESS section of it. And the individual sections
> of IRC Ch12-24 spell out the 18" inch reqt when appropriate but that is
> absent from R330.
>
> Really appreciate the great feedback, Jason. If nothing else, this was a
> good exercise in Code refresher for me and to navigate a way-too-complex
> IRC that is too easily over-applied by an AHJ. At least my own city's AHJ
> (the site of the project) was open to robust debate and thick-skinned
> enough to reverse himself.
>
> Phew...this would have been an expensive "de-retrofit" And I'll say again,
> the Enphase ESS in a six battery config is awesome. 24,000-watts of
> continuous power and "whole house" backup is easily gained. Little long
> time-wise to wire the six together but it's a nice setup. Very pleased with
> it.
>
> *Howard "Scot" Arey*
> *Owner, Solar CenTex*
> 254-300-1228
>
> ------------------------------
> *From:* RE-wrenches <re-wrenches-bounces at lists.re-wrenches.org> on behalf
> of Ray Walters via RE-wrenches <re-wrenches at lists.re-wrenches.org>
> *Sent:* Thursday, September 11, 2025 1:39 PM
> *To:* re-wrenches at lists.re-wrenches.org <re-wrenches at lists.re-wrenches.org
> >
> *Cc:* Ray Walters <ray at solarray.com>
> *Subject:* Re: [RE-wrenches] My AHJ insisting on "Flammable Vapor
> Ignition Resistant" 18-inch requirement
>
>
> I second Jason's sentiments.  We need to 'gently' but firmly push back on
> all these extra code requirements, otherwise we'll be so buried, we won't
> be able to stay in business.  We've been under attack from various factions
> since the 1980s, who have thrown unreasonable requirements at us.  Recall
> utilities requiring gold plated disconnects or million dollar liability
> policies to grid tie. Many folks are trying to politicize our industry, and
> we need to let everyone know that energy independence is very American.  So
> is safe, affordable construction.
>
> Ray Walters
> Remote Solar
> On 9/11/2025 4:17 AM, Jason Szumlanski via RE-wrenches wrote:
>
> I have had AHJs try to shoehorn solar panels into the mechanical code
> before. I think your best bet is to argue the applicability of the
> mechanical code entirely. Expressio unius est exclusio alterius / The
> expression of one thing implies the exclusion of others. If the IRC authors
> wanted M1307.3 to apply to ESS, they would have said so in R328.
>
> I would go with something like:
>
> This equipment is a UL 9540-listed energy storage system, specifically
> tested to the UL 9540A standard. The applicable section of the IRC is R328
> (or 2023 IRC Section 327), not the mechanical code. Chapter 13 applies to
> mechanical appliances such as HVAC equipment or combustion devices—not
> sealed electrical ESS. This product does not fall under the scope of
> M1301.1 and is not subject to M1307.3.
>
> If they don't accept that, I would ask them to:
>
> Point to the section in M1301.1 that covers ESS. Explain why R328 doesn’t
> apply, despite being specifically titled “Energy Storage Systems.”
>
>
>
> On another subject, I have been involved in another AHJ battle regarding
> protection against vehicular traffic, and I have a blog post on the subject
> coming out soon. Fortunately, the next Florida Building Code draft mirrors
> the IRC, which includes a clear schematic that clarifies the requirements.
>
> Good luck, and don't let them win!
>
>
> Jason Szumlanski
> Principal Solar Designer | Florida Solar Design Group
> NABCEP Certified Solar Professional (PVIP)
> Florida State Certified Solar Contractor CVC56956
> Florida Certified Electrical Contractor EC13013208
>
>
> On Tue, Sep 9, 2025 at 3:46 PM scot.arey--- via RE-wrenches
> <re-wrenches at lists.re-wrenches.org> <re-wrenches at lists.re-wrenches.org>
> wrote:
>
> Seeking your suggestions and direction. My AHJ - after acknowledging that
> the Enphase 5p battery has a floor mount option - now insists that it must
> be 18-inches above the garage floor unless I can produce something that
> says it is "Flammable Vapor Ignition Resistant."
>
> We all know there is no open flame from an ESS and I know the 9540A
> depicts a battery at 6-inches.
>
> Anybody run into this and have suggestions on what I might show back to
> the AHJ?
>
> *Howard "Scot" Arey*
> *Owner, Solar CenTex*
>
> NABCEP PV Installation Professional
> TECL 29755
> 254-300-1228
>
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