[RE-wrenches] Batteries in a dwelling - Venting Concorde AGMs

Tue Jul 29 11:22:17 PDT 2014

I don't have that reference, but I believe that IFC 608 only comes into 
play with large banks with 50+ gallons of electrolyte.

On 2014/7/29, 14:10, Glenn Burt wrote:
>
> Also look to see if the fire code in your state has additional 
> restrictions.
>
> In New York Stat, the 2010 Fire Code contains a section (608) with 
> more regulations to be heeded when installing 'stationary storage 
> batteries'.
>
> -Glenn
>
> *From:*RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] 
> *On Behalf Of *Drake
> *Sent:* Tuesday, July 29, 2014 12:01 PM
> *To:* RE-wrenches
> *Subject:* Re: [RE-wrenches] Batteries in a dwelling - Venting 
> Concorde AGMs
>
> This is a reply to a post by Alan from June 21st. I'm replying because 
> I've had to deal with this issue also. It seems to me that the 2014 
> NEC Handbook is _fairly_ clear that we are not required to vent any 
> batteries to the outside.
>
> *"480.9 Battery Locations
> *Battery locations shall conform to 480.9(A), (B), and (C).
> *(A) Ventilation. *Provisions appropriate to the battery technology
> shall be made for sufficient diffusion and ventilation of gases
> from the battery, if present, to prevent the accumulation of an
> explosive mixture.
> Ventilation is necessary to prevent classification of a battery location
> as a hazardous (classified) location, in accordance with
> Article 500.
> Mechanical ventilation is not mandated. Hydrogen disperses
> rapidly and requires little air movement to prevent accumulation.
> Unrestricted natural air movement in the vicinity of the battery,
> together with normal air changes for occupied spaces or heat
> removal, normally is sufficient. If the space is confined, mechanical
> ventilation may be required in the vicinity of the battery.
> Hydrogen is lighter than air and tends to concentrate at ceiling
> level, so some form of ventilation should be provided at the
> upper portion of the structure. Ventilation can be a fan, roof ridge
> vent, or louvered area.
> Although valve-regulated batteries are often referred to as
> "sealed," they actually emit very small quantities of hydrogen gas
> under normal operation and are capable of liberating large quantities
> of explosive gases if overcharged. These batteries therefore
> require the same amount of ventilation as their vented
> counterparts."
>
> I think that the confusion come is with the statement "These batteries 
> therefore
> require the same amount of ventilation as their vented
> counterparts."
>
> As we see from the statement "Unrestricted natural air movement in the 
> vicinity of the battery,
> together with normal air changes for occupied spaces or heat
> removal, normally is sufficient," the concern is with explosive gasses 
> being restricted to a small area, where explosive concentrations of 
> hydrogen can build up.
>
> The article also has the statement "Provisions appropriate to the 
> _battery technology_" which should be taken into account. In practice, 
> liquid electrolyte batteries stink and emit toxic fumes, so we do vent 
> these outside.
>
> It does sound like different voices have worked their way into this 
> code section, which can open the way to various interpretations. But, 
> if you look at the photos in the NEC Handbook of batteries, they are 
> on unenclosed racks inside of a building.
>
> Drake
>
>
>
>
> At 12:06 AM 6/22/2014, you wrote:
>
> Bob,
> We had a case in February in which an AHJ insisted that we vent a 
> Midnite cabinet with a dozen 2V 9150T batteries. We fought it all the 
> way to the state Technical Advisory Committee, the top arbiter of Code 
> issues. We fought to a draw: we finally agreed to put in the vent to 
> get our final passed, and the committee permanently tabled the issue 
> so there is no precedent set. To continue to fight this would have 
> required bringing in professional engineers, as some of the committee 
> members were reluctant to make their own decisions about the issue and 
> wanted to pass the buck. As I recall, the Zephyr Power Vent was 
> ultimately never hooked up to the Classic controller's auxiliary, as 
> the necessary work was handled by the GC (rather than by us) at a 
> quite remote location. The challenge to the AHJ was a pain in the 
> butt, although we were paid by the clients for the effort, as they 
> agreed with the absurdity of the inspector's demand.
>
> I have attached a few documents I gathered and prepared in this case. 
> You do not need to vent AGMs if the larger space in which the battery 
> enclosure is located has a typical and normal amount of natural air 
> circulation and convective air exchange. Also, you can't duplicate 
> what Kevin describes below with a vented enclosure - Kevin's approach 
> requires a "sealed and vented battery enclosure". By design, your 
> enclosure is unsealed.
>
> Putting in vents "for the next guy" also makes no sense. If you 
> install 8 flooded L16s on two shelves in a Midnite MNBE-Cl16 
> enclosure, you won't be able to routinely add water to the cells. The 
> cabinet was designed and built for VRLA batteries. So any venting you 
> install now would have to be redone to fit a cabinet built for flooded 
> batteries with top access.
> Allan
>
> *Allan Sindelar*
> allan at sindelarsolar.com <mailto:allan at sindelarsolar.com>
> NABCEP Certified PV Installation Professional
> NABCEP Certified Technical Sales Professional
> New Mexico EE98J Journeyman Electrician
> Founder (Retired), Positive Energy, Inc.
> *505 780-2738 cell*
>
>
> On 6/21/2014 1:30 PM, Bob Clark wrote:
>
> RE-Wrenches:
>
> 2014 NEC 480.9 (A) has two informational notes that seem to point to 
> the possibility of not having to vent AGMs.
>
> Here is what I was going to do with 8 Concorde SunXtender Batteries, 
> 6V, 405Ah, L16, PVX-4050HT:
>
> 1.  Put them in a Midnite Solar, MNBE-CL16 Battery Enclosure (which is 
> not a sealed box) in a "battery closet."
> 2.  Vent the box out of the top of the box and through the wall of the 
> house with pipes like Kevin Pegg suggests.
>
> Do any of you see any problems with this?  Venting unnecessary?
>
> One consideration is the "next guy" who occupies this house may want 
> flooded batteries, in which case, the vent system would definitely be 
> necessary.
>
> Bob Clark
> bclark at solar-wind.us <mailto:bclark at solar-wind.us>
>
>
>
> On Apr 4, 2014, at 2:49 PM, Kevin Pegg <kpegg at energyalternatives.ca 
> <mailto:kpegg at energyalternatives.ca>> wrote:
>
>
> Hi William,
>
> In the cold north here in Canada, this is the most common way we 
> install batteries - within the heated envelope of a home or shop, 
> installed in a sealed & vented battery enclosure.
>
> Hydrogen is easy to vent as it is lighter than air. We use a process 
> similar to below. I see a lot of installations with power vents that 
> are not done properly - exhaust only but no intake as example. They 
> can also fail. Or installed in such a way that outside wind influences 
> could actually reverse the flow and pressurize the battery box! Air 
> flow needs to be balanced.
>
> http://www.bdbatteries.com/hydrogenventing.php
> To remove the thermal air currents present in a battery box venting 
> system, you must create a natural heat sink between the vent tubes to 
> neutralize the difference in temperature. This in turn will stagnate 
> the air, allowing the hydrogen which is lighter than air, to rise and 
> escape the battery box. Make sure the smaller tube, the one inside, 
> extends to the bottom of the box. This will allow "heavier" fresh air 
> to fall to the floor of the box and retard hydrogen entry. The intake 
> for the hydrogen is at the top of the box, the exterior tube in the 
> system. Hydrogen will travel in the opposite direction through the 
> larger outer pipe as it is lighter than the air surrounding it. 
> Several good methods for constructing this vent system exist, we 
> particularly like to see 1/2 inch copper pipes inside 1 inch pipe. Any 
> highly conductive metal pipe will work it will transfer heat quickly. 
> Galvanized, steel, and other pipes that spark when rubbed aren't as 
> great. DO NOT USE THESE IN EARTHQUAKE ZONES.
>
> DO NOT USE PVC FOR THIS VENT SYSTEM....PVC DOES NOT CONDUCT HEAT WELL 
> ENOUGH! Copper, aluminum, and other non sparking conductive metals are 
> great!
> <Outlook.bmp>
>
> <Outlook.bmp>
>
> -----Original Message-----
>
> From: re-wrenches-bounces at lists.re-wrenches.org 
> <mailto:re-wrenches-bounces at lists.re-wrenches.org> 
> [mailto:re-wrenches-bounces at lists.re-wrenches.org 
> <mailto:re-wrenches-bounces at lists.re-wrenches.org>]On Behalf Of 
> william at millersolar.com <mailto:william at millersolar.com>
>
> Sent: April 4, 2014 9:29 AM
>
> To: RE-wrenches
>
> Subject: [RE-wrenches] Batteries in a dwelling
>
> Friends:
>
> I am proposing installation of vented batteries in a first floor 
> garage of a dwelling.  The dwelling areas are on the second floor.  I 
> am nervous about the cohabitation of batteries and humans.
>
> I reviewed the NEC and could not find any prohibition.  Do any of you 
> have any advice on how this is accomplished in the mot safe manor?
>
> I presume good ventilation and an otherwise sealed room are advised.  
> I will propose additional smoke detectors, locked doors and I will 
> research hydrogen detectors.  A good spill kit and all PPE will be 
> staged as usual.
>
> Thanks in advance for the forthcoming, always expert advice.
>
> William Miller
>
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