[RE-wrenches] Explosion proof ceiling fan

[Bradley Bassett]

Put the fan at the intake near floor level and a passive vent at the
ceiling



On Tue, May 6, 2025, 12:09 PM Ray Walters via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Hi William;
>
> Poor ventilation could be part of it, but I've also seen corrosion
> problems from:
> clients over filling the cells,
> EQing to often,
> absorption voltage set too high and for too long,
> too high a charge rate, (too large an array)
> too high a temperature, due to floor heating and/or insulated battery box.
>
> my best systems seem to be on the lower side of array size relative to
> battery size, with batteries in a basement or garage that stays above
> freezing, but below 60F most of the year.
>
> Sorry I don't have a line on explosion proof fans, but I have a client
> with a 120 vac radon blower for the battery exhaust that seems to do much
> better than the traditional DC battery fans.  (Not my install.)
>
>  I've only seen batteries blow twice:
> 1) Idiot was arc welding next to a HUP battery and multiple large sparks
> went right on to a cap; result: blew the top off the cell. He had been told
> to construct a battery enclosure around the batteries, but never did.
> 2) a loose connection at a battery terminal arced, melted the lead until
> the molten lead melted through the top of the case and ignited the
> hydrogen, result: burned a clear flame for a few seconds and went out
> without any major damage.
>
> So my take away is that unless the ignition source is in the cell or
> within an inch of the cap, the hydrogen is too low a concentration to
> ignite.  Actually, are lead acid battery internal plates and their external
> connections considered "explosion proof"?
>
> Ray Walters
> Remote Solar
>
>
> On 5/6/2025 12:20 PM, William Miller via RE-wrenches wrote:
>
> Friends:
>
>
>
> I have two flooded battery arrays that have steel cases that are
> corroding.  I am sure poor ventilation is the issue even though we have
> passive vents high and low.  I think I need active ventilation.
>
>
>
> Does anyone have knowledge of a 120VAC explosion proof ceiling mounted
> exhaust fan?
>
>
>
> Thanks in advance.
>
>
>
> William
>
>
>
> Miller Solar
>
> 17395 Oak Road, Atascadero, CA 93422
>
> 805-438-5600
>
> www.millersolar.com
>
> CA Lic. 773985
>
>
>
>
>
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