Putting the fan on the intake causes the battery box to be at higher
pressure. You don't want the pressure in the battery box to be higher
than the surrounding room, or it will push the H2S into the room through
any cracks. You want to create a vacuum (lower pressure) in the
battery box, so that the H2S is less likely to enter the room, and is
drawn out. That's why we always put the fan on the exhaust side.
Ray Walters
Remote Solar
On 5/6/2025 1:20 PM, Bradley Bassett wrote:
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
<[email protected]> 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 <http://www.millersolar.com/>
CA Lic. 773985
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here:http://re-wrenches.org
List Address:[email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the
other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work,
try the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
