question about co2

BigBudBalls

BigBudBalls

Well-Known Member
BloodShot420 said:
c
I am using a PLC, which runs my whole system... i spent a few hundred bucks on it, but it replaces all of the timers and controllers... and you write the program that runs on it yourself... the PLC controller is about $189.

a solid state, self-calibrating co2 sensor from 0-2000ppm can be hooked up to it to read exactly how much co2 is in the air... this is also about $189
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But that monitor doesn't have an output (I know the one you are talking about) How is the PLC going to know the actual level of CO2? There is no analog or serial output. Digital output is a misgiving. Won't allow for any proportional or fuzzy logic control)

then you need a co2 tank, with a pressure regulator (every soda fountain has one), and a solenoid... the solenoid is a valve that opens when the PLC tells it to, usually with some DC voltage... you should be able to get this setup for under $200... the regulator solenoid are about $50 each, but you can find them for less... and tanks are everywhere, and should be able to be found on the cheap. You would need this part no matter what co2 controller you went with.
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(doesn't have to be a DC voltage. Plenty of AC solenoids out there) But DC is nice, easier to enable a proprtional valve.

But with no monitor, I agree, its all guess work. (does one water and add nutes via guess work??)
 
Perfextionist420

Perfextionist420

Well-Known Member
co2 does help your plants and the easiest way to get it..... open a window!!!!!!

lol i have a window ac unit bringing in fresh air to the flowering room which supplies my plants with all the co2 they need 24/7, as for my veg room i leave the window cracked just a little and they grow fine.
 
BigBudBalls

BigBudBalls

Well-Known Member
Perfextionist420 said:
co2 does help your plants and the easiest way to get it..... open a window!!!!!!
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maybe NOT my outdoor CO2 ppm level is abot 400-420 my indoor live alone, 1500sq ft) is 600-700pm

lol i have a window ac unit bringing in fresh air to the flowering room which supplies my plants with all the co2 they need 24/7, as for my veg room i leave the window cracked just a little and they grow fine.
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*Only* if its set to; (damper opened). Heating outside air, then bringing it indoors is kinda a poor use of energy for a window AC unit (they were NOT thinking of a grow room when designing the window AC unit)

And if you are not on the 24/0 light schedule, plants won't use CO2 during the dark period.
 
B

BloodShot420

Well-Known Member
BigBudBalls said:
But that monitor doesn't have an output (I know the one you are talking about) How is the PLC going to know the actual level of CO2? There is no analog or serial output. Digital output is a misgiving. Won't allow for any proportional or fuzzy logic control)



(doesn't have to be a DC voltage. Plenty of AC solenoids out there) But DC is nice, easier to enable a proprtional valve.

But with no monitor, I agree, its all guess work. (does one water and add nutes via guess work??)
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the PLC controller i use has 2 analog inputs... (and 2 outputs) the co2 sensor has a 0-10v analog output which represents 0-2000ppm... (you feed that to one of the analog inputs on the PLC) so if you get 5v thats 1000ppm... 7.5 volts would be the 1500ppm mark that everyone is aiming for... you can read this value in the PLC programming software. you just program it to open the solenoid until it sees 7.5v on the analog input.

the solenoids will come in any flavor, i like DC voltage for things like that though, because my PLC uses 24v DC for its digital outputs (you have to get a separate module for AC outputs)... also, you wont get shocked by DC if you ever accidentally touch it.
 
BigBudBalls

BigBudBalls

Well-Known Member
BloodShot420 said:
tthe co2 sensor has a 0-10v analog output which represents 0-2000ppm... (you feed that to one of the analog inputs on the PLC) so if you get 5v thats 1000ppm... 7.5 volts would be the 1500ppm mark that everyone is aiming for... you can read this value in the PLC programming software. you just program it to open the solenoid until it sees 7.5v on the analog input./quote]

Got a link to the sensor? (Though 2000ppm is a bit low/tight)

I have a few wireless transceiver and a few temp / RH sensors. Can make a wireless sensor for various rooms
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B

BloodShot420

Well-Known Member
http://www.dwyer-inst.com/Products/Product.cfm?Group_ID=20017

i showed you this one before... you would never want your co2 over 2000ppm (which is toxic to the plant i hear) its the perfect range....

the cheaper one you showed me went to 10,000ppm which is a bit too wide, if you were trying to hit 1500ppm you would be watching for 0.15v - and you would never know if you had it calibrated right... also, i think the voltage resolution on my plc is .1v
 
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