CO2 / Alarm Setup

[ceosam]

My room has access to a natural gas line and I'll be installing a burner, making it my first time running CO2 (Titan Atlas 3 + Ares 4). Room is sealed up tight but I will be running a nighttime exhaust -- mostly for the smell buildup but I've heard its good to get some fresh oxygen in there).

Safety is a concern, I am already a bit uneasy about having a flame in there... But gas poisening is also on my mind, what if the sniffer stops working and it just stays on? Could be dangerous. What are the ways I can minimize risk? I have looked in to 'co2 alarms' but they are for carbon monoxide... and most go off at 500ppm. Firstly, will CO2 trigger a monoxide alarm & do they sell alarms that can be adjusted (to say, 2000ppm)?

Trying to keep it safe here. Any input is appreciated.

 

[The Meadows]

You could get another Atlas 3.

Or you could get a $20 arduino, $10 lcd, and a $35 CO2 sensor and write your own code. You could have it turn a device on or off (alarm), turn a valve, send a text message, etc. if the ppm exceeded whatever value you choose. Eventually, the arduino would replace the atlas.

 

[ceosam]

Very interested in the arduino recently... I've looked into in and was abit clueless amount where to start. At the very least I'd like to build a 10 probe temp monitor so I can minimize hotspots. Do you have any golden resources you might point me to? I'm aware of google.com but not all guides are created equal for extreme beginners.

 

[budleydoright]

Buy good gear and keep it in good condition, check regularly for proper levels. Remember this is Co2, not CO. You can tolerate incredibly high levels of co2 where CO will kill you.

You can buy an alarm on ebay for under 200 bucks. Many co2 controllers will output 0-10v. You could always connect that to a device that alerts you.

I use a tank less water heater. I set it on the lowest flame and highest water flow. I have used Co2 sealed with propane (natural gas burner arrives in a couple of days) for a few years with 0 incident.

 

[The Meadows]

Very interested in the arduino recently... I've looked into in and was abit clueless amount where to start. At the very least I'd like to build a 10 probe temp monitor so I can minimize hotspots. Do you have any golden resources you might point me to? I'm aware of google.com but not all guides are created equal for extreme beginners.

I have 8 dht11's ($5 for 8), 5 ds18b20's ($10 for 5), 10 relays ($1 each), and 10 led's (free-laying around) connected to a arduino mega clone ($20). I also used over 1000' of wire. Get a 100' roll of network cable and you'll have 800' of wire. I could have used more wire to make it neat and maybe provide shielding.

I suggest sticking to sensors that already have a library for arduino. It makes coding much simpler. The coding to read the sensors is usually very easy to implement. The tough part of the coding is the error checking and what if scenarios.

I got all my stuff thru amazon. Searched for what I wanted then sorted by lowest price. Most stuff got to me within a week but some stuff from china took nearly a month.

Some sensors can be expensive (co2). Some have limited lifetime (pH). Some would be cool to have (ec/ppm, o2, water level, media moisture level, motion, lumen, etc.). But things get complicated quickly.

 

[exploziv]

Where are those 35 usd CO2 sensors sold? Couldn't find any that's so cheap on ebay.

 

[The Meadows]

Where are those 35 usd CO2 sensors sold? Couldn't find any that's so cheap on ebay.

I had found the $35 sensor on a website other than ebay but can't find it now.

Here is an ebay item: http://www.ebay.com/itm/like/301191399526?lpid=82
$39 + $5 shipping

 

[exploziv]

Thank you for your answer. I have found that item before on ebay but it says nothing about sensor resolution and precision. Seems too expensive for what it does, and with no positive feedback from others I would not consider buying it.
Do you have any experience with that sensor (MG811)?

 

[The Meadows]

Thank you for your answer. I have found that item before on ebay but it says nothing about sensor resolution and precision. Seems too expensive for what it does, and with no positive feedback from others I would not consider buying it.
Do you have any experience with that sensor (MG811)?

I don't use co2 or co2 sensors, yet. Its datasheet http://sandboxelectronics.com/files/SEN-000007/MG811.pdf says 350-10000 ppm.

 

[exploziv]

Thank you very much for the datasheet link. I reallly apreciate the help!

Except the fact that seems hard to precise calibrate it without having another better CO2 sensor/controller, do you see any other problems with this sensor?
And secondly, would you buy this one, or a better one?

 

[The Meadows]

https://www.youtube.com/watch?v=50EfMy-mOPA

It would be interesting to know what sensor the Titan Atlas uses. It wouldn't surprise me if it was a mg811.

I'm cheap, I'd get the mg811. You can get the sensor itself for about $10 but then you need an op amp to scale the voltage to a level readable by the arduino. And then figure out how to wire it all together in a compact and solid form. I'm cheap but not that cheap.

 

[budleydoright]

I'm pretty sure all commercial co2 controllers on the market use NDIR sensors.

 

[The Meadows]

NDIR = $110 = no calibration required. Might need one of those to calibrate the cheap ones.


http://www.futurlec.com/Gas_Sensors.shtml