Hood for Venting Gas

KJ7YM

So I have four Crown CR185 batteries in a 10 X 12 room running on a 1K Array. They are in a tray and not a box for better cooling. This system is dedicated to my refrigerator only. At times after equalization I can definitely smell the process, Hydrogen is odorless, colorless and tasteless so I know I am not smelling it directly. I am not convinced that it is at explosive levels in an area this size, but I do have an electric washer and dryer in the room. The system has been running for about four or five months now. I have thought about using a 2" vent pipe about 5 feet above the batteries and with a simple hood to collect the hydrogen and move it outside. Much larger of a vent, and I think the impact on my Air Conditioning bill might just offset the Solar advantage. I have never seen hoods mentioned though. Has anyone else tried this?

MarkC

I've kept a golf cart with four deep cycle Interstates inside a garage area for several years. The ceiling is vaulted and "paneled" with corrugated tin. The "fumes" have obviously tarnished/corroded the tin - would expect you are getting corrosive fumes in your room - maybe just nothing to show as a result. I've been involved in dust collection system designs in the past and would not expect a hood mounted 5 feet above the batteries, with what is termed as "gravity flow" (basically like a chimney effect), would make much difference in the concentration of fumes in the room - especially with only a 2" pipe. Likely need a battery box.

Vic

If there is much active air circulation (fan-forced) in the room, A/C for example, the Hydrogen may not all be collected.

My "solution" has been to place a vent pipe at the highest portion of the ceiling, making it flush with the ceiling paneling/drywall -- ie, no lip., This, plus two screened air inlets very low in the room (usually one through the floor to a crawl space or similar).

Things have not exploded, yet . We may be a bit too casual about this important venting, but Hydrogen is very light, and wants to get out of containment.

Just my opinions. Would never want to minimize the need for this important ventilation.

And if you smell a Sulphur-like aroma AFTER EQ is done, in a room with some natural ventilation, perhaps the EQ was not fully completed. IT can take some time for this aroma to dissipate, but on systems that I watch, try to EQ, until there is no added aroma.

FWIW, Vic

westbranch

what are your charge / EQ settings at, Volts and time....? If the smell is not coming with the EQ you may be a little high on the absorb V setting....

KJ7YM

Thanks guys,
My plastic hood which we found yesterday is just large enough to fit 1/2 inch over the batteries with enough room for the cables that fold down over the side of the batteries and then run along the floor to the controller. I also purchased enough 1/2 PVC to run up to the ceiling where it will exit through the wall and the turn down to keep moisture out. In my first post, I mentioned that I was planning on a 2" pipe. I revised that plan, believing the gas should flow well enough through the 1/2" path.

So about that smell. I don't really associate it with Sulfur but is instead a lightly detectable smell that kind of reminds me of what a De-ionizing air purifier leaves behind. I really cannot put my finger on it. It is what I would call the tinge of an odor. It could be the sulfur I guess. Anyway it seems to be some byproduct of charging heavy.

Thanks guys for your input. I had been playing with the idea of placing a small box on the wall outside of the wall and piping into it, then using a very tiny solar powered fan to keep a flow in the pipe. But I have abandoned any idea of any electrical anything, being placed in the path of an explosive or flammable mixture. :-)

Vic

Hi Larry,

To me, 1/2" vent pipe seems quite small, but your battery bank is not huge, and Hydrogen does want to rise ...

Your Crown batteries must be Flooded, since you are concerned about venting. So, the hood sits down very close to the tops of the batteries, perhaps down the sides of the case a bit ... are you planning to remove this hood for checking SG and adding water?

IMO, the more cumbersome is the access to the batteries, often, the less frequent is the all-important maintenance. So, hope that the hood is never in the way, or, that it takes only seconds to remove and replace the hood.

And, on the aroma, Sulphur smells like rotten eggs, and generally is easy to detect this smell in small concentrations, so perhaps you are smelling the acid vapor.

There are inexpensive venting fan accessories that fit two or three-inch pipe, and run on 12 or 24 V, IIRC. Zephyr is one brand that comes to mind. Here us a link to the model that fits 2" pipe from the host of this Forum:
http://www.solar-electric.com/batteries-meters-accessories/batteries/baacma/zephyr-battery-box-ventilator-12-24-volts.html

This unit is not inexpensive, and one could probably home-brew one for less, if one has access to a variety of muffin fans.

IMO, a 2-inch pipe would not have any significant impact on your A/C demands, but, I do not live in AZ, so whatta I know?!?

FWIW, Good Luck, Vic

Johann

Don't take hydrogen gas lightly. Years back I almost blew all my windows and doors out in my house. I made hydrogen and I put it in a 6 oz coffee styrofoam cup and it blew up.
My house was big and it rattled the whole house and all my windows, doors and furniture when it happened and all because of 6 oz worth of space of hydrogen.
So be careful, dealing with hydrogen gas.

KJ7YM

We hear ya Johann,
Several years ago I had a really big RC model racing trucks battery short out on the work bench. I saw it swelling and ran. We got a new set of bay windows that day. Man was my wife unhappy! :-)