# CO2 detector



## greenfin (Nov 4, 2013)

Wondering if people use these for their pressurized set-ups. My husband is wondering if potential leaks are a health risk. Particularly for our small child. I have a 5lb aluminum tank with solenoid/regulator. Where might I get one and how much might they cost?

I'm having problems with my set-up today (tank 3.5lbs full and no CO2 coming out of diffuser). My husband was playing with the regulator and had it full open when "pop" the tubing popped off the solenoid valve and was hissing like crazy before he unplugged the solenoid. This had him worried...I said I'd ask on the forum!

Thanks


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## Dietmar (Dec 15, 2011)

If the tubing popped off after the solenoid, then something is plugged in the line to the diffuser.
Check for a kink or a restriction at the diffuser.


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## Reckon (Jul 25, 2012)

Edited: after doing some research

Here's some data on what's acceptable and what levels are harmful:

CO2 is present in the atmosphere at 0.035% (Aerias 2005; CCOHS 2005). In terms of worker safety, Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit (PEL) for CO2 of 5,000 parts per million (ppm) over an 8-hour work day, which is equivalent to 0.5% by volume of air. Similarly, the American Conference of Governmental Industrial Hygienists (ACGIH) TLV (threshold limit value) is 5,000 ppm for an 8-hour workday, with a ceiling exposure limit of 30,000 ppm for a 10-minute period based on acute inhalation data (MDPH 2005; NIOSH 1976). A value of 40,000 ppm is considered immediately dangerous to life and health based on the fact that a 30-minute exposure to 50,000 ppm produces intoxication, and concentrations greater than that (7-10%) produce unconsciousness (NIOSH 1996; Tox. Review 2005). Additionally, acute toxicity data show the lethal concentration low (LCLo) for CO2 is 90,000 ppm (9%) over 5 minutes (NIOSH 1996).

References below

Conversion:
At normal temperature and pressure

1lb CO2 = 4160ppm = ~8.7 cu. ft

*Example* Assuming the SEALED ROOM is medium sized at 20' x20' x8' = 3200 cu. ft

Atmospheric CO2 = ~350-400ppm

Adverse exposure starts at ~ 2500ppm (symptoms such as rapid breathing, rapid heart rate, clumsiness, emotional upsets and fatigue can result)

Using the calculator here (based on assumptions of a grow room):
http://www.hydrofarm.com/resources/co2calc.php

To reach the threshold of 2500ppm, we need to inject 6.7 cu. ft to reach adverse exposure threshold, or 0.77lbs or 12oz of CO2.

To reach the threshold of 30000ppm, we need to inject 94 cu. ft to reach the ceiling exposure limit for a 10-minute period, or ~11.0lbs of CO2.

But just like in the website. CO2 level in a sealed room returns to normal in 180 minutes, due to leakage and plant usage. Probably a bit slower if plant density is much lower than that of a grow room.

Conclusion:

This means that you would have to release about 1/5th of your 5lb tank into a SEALED medium sized room and remain in there in order to notice the beginnings of adverse symptoms to too much CO2.

However, if you release a full 10lb tank of CO2 all at once into the same sealed room, it's not healthy to stay in there but won't hurt you right away.

Release 15lbs or more it's best to leave the room and come back when it has aired out.

Don't forget that CO2 is heavier than air so being higher up gets you more O2.

(Correct me if my information, numbers, calculations are wrong)

More info on CO2 poisoning:

http://www.engineeringtoolbox.com/co2-comfort-level-d_1024.html

http://www.ccohs.ca/oshanswers/chemicals/chem_profiles/carbon_dioxide.html

http://www.blm.gov/pgdata/etc/medialib/blm/wy/information/NEPA/cfodocs/howell.Par.2800.File.dat/25apxC.pdf


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## Rockman (May 19, 2013)

Very thorough Reckon. Good to see someone did the math.

Of course, the big unknown is how well the gas is mixed in the room. If there's not a lot of air circulation you could get a pool of CO2 near the floor; which could (in theory) be a concern for pets and small children. I have no idea how likely this is in practice though.


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## greenfin (Nov 4, 2013)

Wow, how wonderfully thorough!
I'll get my husband to read it over tomorrow. Thank you so much! I bet he'll be reassured.

Our house is mostly open floor plan with high ceilings. I think air circulation is pretty good. I bet any CO2 would leak down the nearby basement stairwell.

I did some internet research of my own and did not find anything as thorough as your posting, Reckon. There are people who are concerned because their tanks are in their bedrooms (door closed at night). Many people seem to confuse CO (carbon monoxide = silent killer) with CO2. I know they are not the same but I do know of some fatal accidents concerning wine-making and CO2 exposure.

It doesn't seem as if a CO2 detector is useful in this situation. Apparently most are unreliable anyway.

Meanwhile, my CO2 still isn't flowing but I've narrowed it down to the diffuser. I've had it soaking in H2O2 all day to see if that loosens/dissolves something.

Hooray BCA'ers!


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## Reckon (Jul 25, 2012)

Just curious how big is the room that tank is in anyways?


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## greenfin (Nov 4, 2013)

uh, it's open plan main floor but it's shaped like an "L" with the tank in the middle of the vertical part of the "L". 







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Maybe 36 feet end to end and 24 feet deep? Guessing. It's fairly open with a 20' vault in the area above the tank. You can see the basement stairs in the pic.


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## greenfin (Nov 4, 2013)

I guess a worry would be if the CO2 leaked into the cabinet and my daughter had her head/shoulders in there rummaging around with the fish stuff. I keep the doors shut with thick rubber bands and that's been baby-proof so far.


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## shift (Dec 21, 2012)

Use a paintbrush and soapy water. Brush over all connections and ensure no bubbles form.


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## shift (Dec 21, 2012)

If you want an actual co2 detector I think I have one


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