venting co2 from gas hot water heater into grow room

[SKUNK420]

Yes it will work, is it exactly safe you can decide. I know because I have that problem right now. I only call it a problem because the gases from the hot water heater should be exhausted to a safe area which is out to the roof vent. I'm just concerned that the air being sucked down the roof vent backward into the heater can affect combustion which may cause carbon monoxide to be sucked into the room.

My grow room is in the garage and it's sealed but I do have an exhaust fan plugged into the co2 controller's dehumidifier outlet. When humidity gets to high and the dehumidifier can't keep up then air is pulled into the grow room through a hepa filter and duct damper. I got a 10"vortex for the lights and a 10,500btu window a/c that pull such a vacuum into the garage that it also pulls the air down from the hot water heater vent. The co2 gets into the grow room when the exhaust fan turns on, until then its just floating around the garage being sucked into the lights and window a/c box then out to the attic. I know it works because the co2 controller says so. When hot water is running the heater fires up and the ppm's slowly start to rise. At times it will max out the meter. Usually when the shower is running or washing dishes.

It's been like this almost a year now so it's not that big of a problem yet but I will build a box/room around the water heater with it's own fresh air supply. It'll be easy it's in the corner.

update: here's a diagram of my room to help understand.

this room is history...........2011

 

[Dr BurnBud]

Please be careful! I run co2 in two rooms. It is a tiny flame pure and blue and it only runs for 3 to 5 minutes maybe 3 times per hour. Compare that to a gas water heater flame WOW! I understand you are not pulling all the fumes, that you are just taping some of the exhaust but alot of it is going to be monoxide. You better have a meter or controller or you will be found in your grow. Heavier than air, you could poison your whole house.
BUT BOY THOSE PLANTS WILL BE DARK GREEN! LOL

good luck and be smart,
Dr. BurnBud

 

[compost]

Everyone has hit the CO problems this presents so I will bring up the other problem. That CO2 enriched air from your hot water heater is gonna be hot. Watch out for room temps if you take a shower or start a load of laundry. If you take a hot shower when your lights are off your room will be inundated with a ton of CO2 it can't use and actually is not good for the plants. Also a CO detector is a no brainer not only in the grow room but in the room under the grow room also.

 

[Sam the Caveman]

The room under the grow room is my garage, the grow room is the furthest point away from the living quarters.

The grow room is only 3' tall and about 5'x11', so the volume of the room is very small. There will be canopy covering 80% of that area and that is why I'm worried about O2 build-up.

As of right now, I have a stanley blower fan in the room pulling through a carbon filter and exhausting into an a/c ceiling vent. There is also a 6" flex duct on the opposite end of the grow room from the exhaust fan which runs to a different ceiling duct in my house. This circulates air from the interior of the house through the grow room so it gets proper air exchange.

The exhaust for the hot water heater runs right by the grow room. I would like to seal the room and put that co2 to good use.

Lazyman; I like your idea of electronic dampeners controlled by a co2 controller, I'll look into it. I think those co2 controllers are expensive though, I might could just put a manual dampener just above the Y duct on the hot water heater and just adjust it as needed until I can afford a co2 controller.

I don't have to have 2000ppm of co2 in there, I just don't want the plants starving for co2 if I seal the room.

 

[dtfsux]

As mentioned already its how the gas is burned. I know the hydrogens are/were basically hot water heaters modified. I do know they modified the burners to produce a blue flame.

Also how do you get CO2 when the hot water heater isnt on?

I think for the trouble and risk involved, getting a CO2 tank and controller would be the best option

 

[tokinafaty420]

Depending on which gas is actually being used I would seriously be careful about redirecting the exhaust into your room.

If it is propane the chemical reaction will result in 3CO2 + 4H2O Which is what plants want. If its like the typical East Coast natural gas that is piped into towns then theres a high probability that what you are burning will have carbon monoxide as a by product. Plants cannot use CO for their chemical reactions. Rather what would happen is it would remain in the room until you entered and breathed it in resulting in it attaching itself to your blood cells and causing you to get sick or die.

 

[freshwaterjelly]

i think it's innovative thinking for sure. research and test the shit out of it by safe means. I know Co2 is heavier than what we breathe, so it will fall from your attic down, Id assume CO would as well.get lots of CO detectors too..

 

[eebbnflow]

I hate to say this but I hope no body does this that grows mj . Save some money and buy a tank with regulator 200-400$ .

 

[who dat is]

i think it's innovative thinking for sure. research and test the shit out of it by safe means. I know Co2 is heavier than what we breathe, so it will fall from your attic down, Id assume CO would as well.get lots of CO detectors too..

Grave digging, this thread is almost 6 years old. Otherwise welcome to the boards. This topic has popped up several times at least and I always try to shoot it down as best as possible. For the LOVE OF CHRIST PLEASE DON'T DO THIS! I test water heaters for combustion performance and proper draft, among other things. They are pretty notorious for not performing at 100%, especially as they age. This problem is exacerbated when you get into a state like Colorado where the water heaters are manufactured an configured for lower elevations and when they are brought up to elevation they burn too rich and you can get extremely toxic levels of CO. Couple that with a potentially disfunctional draft hood and exhaust flue and you have a very shitty situation. Trying to vent these exhaust gases anywhere but immediately up and out of your house is a really bad idea. Please do not attempt to do something like this. Instead do as the next poster mentioned and either get a CO2 generator, or better yet a CO2 tank and regulator.

I hate to say this but I hope no body does this that grows mj . Save some money and buy a tank with regulator 200-400$ .

^This

 

[eebbnflow]

I ditched my burner . I was getting weird deficiency like symptoms , yellowing , curling . Came across a thread about hydrocarbons and dirty propane causing poisoning to plants . Tanks all the way ! Sleep better at night ! Ftw

 

[Ttystikk]

I've been going back n forth on this. It's my house, so I don't want to be risky. I have a single pass ventilation system for the whole house, so carbon monoxide would have nowhere to build up.

FYI; Carbon dioxide is heavier than air and will sink unless stirred by fans. Carbon MONOXIDE mixes in the air just fine, it does not pool on the ground.

I think the source of gas matters. Standard hot water heaters aren't made for this. Tankless water heaters might work better. The poster from Colorado above has am excellent point; you need to rejet these for altitude just like a carburetor and of course no one does.

Totally off the wall idea, what about a fuel cell? I don't believe they operate a combustion cycle, therefore no byproducts of incomplete burning.

 

[the gnome]

for everything involved using the house HW heater I'd get the tankless hot water heater.
I have one, $112 for the tankless, $33 for the solenoid and a length of garden hose for DTW or use it in a rez.
it the same thing a the aqua gen at the gro sites at more than 2Xs the price.
i change out a 20lb gas grill tank every 3-4months

easy as pie

 

[Mikell]

CO2 does not settle. That's an easy google.

I ditched my burner . I was getting weird deficiency like symptoms , yellowing , curling . Came across a thread about hydrocarbons and dirty propane causing poisoning to plants . Tanks all the way ! Sleep better at night ! Ftw

Interesting. I've heard you can request cleaner propane from the supplier (sans contaminants re:sulphur).

 

[AvidLerner]

I used CO2 cartridges from paint ball guns. safer and easier. good luck.

 

[St. Phatty]

When you burn natural gas you get H2O and CO2.

So the humidity will go up too.