venting co2 from gas hot water heater into grow room

[Sam the Caveman]

I have a small volume, somewhat sealed environment that I grow in and am considering routing a splitter duct off of my hot water heater vent and running it into my grow room.

The room is roughly 11' long, ~5' wide and 3' tall.

There will be an s&p td150 fan (218 or 293 cfm) pulling air from on end of the room, where the a/c is, through a 6" external duct and blowing in the other end straight across the bulbs.

I plan on putting a 6" duct T right at the intake and running a 4" duct to the 3" hot water heater duct. I'm thinking all the downsizing of ducts will only allow a small airflow from the hot water heater.

To increase CO2 levels, I'll just turn up my hot water heater.

Any thoughts?

Will I need a small fan putting a negative pressure on the room in order to pull air from the hot water heater vent?

 

[SuperThrowed]

how do you plan on regulating the ppm from the hot water heater?

 

[SmokinErb]

Guess he just plans on just getting whatever he can get. I mean it is free basically.

 

[Sam the Caveman]

If it needs more, I'll turn up the hot water heater.

I don't think the co2 ppm will get up very high on the setting it is on now. I do plan on testing it with one of those tester kits once it gets up and running and then adjusting it from there where it needs to be or as high as I can get it.

It should get higher than the regular indoor co2 levels.

 

[Classyathome]

Something in my head rang out a warning about CO - carbon monoxide...

Don't know why - can't think of why...

Be careful, Sam...

 

[guest2012y]

Don't kill yourself Sam....People die because of this shit. I'm sure you're smart enough to figure it out so it's safe. Good luck

 

[transplant]

DITTO!

DITTO!

Something in my head rang out a warning about CO - carbon monoxide...

Don't know why - can't think of why...

Be careful, Sam...

The best to do instead of pipeing it in is to open the trap door on the bottom & crank it all the way up! I used to heat my country house like that in the utilty room. If it produces heat in the room there will be gas also.

 

[arrg]

Something in my head rang out a warning about CO - carbon monoxide...

Don't know why - can't think of why...

Be careful, Sam...

You might die from CO if you do this. I would imagine co2 generators have built in CO monitors or shutoffs. To just vent the exhaust of the water heater into a house is certain death in my mind.

 

[Sam the Caveman]

Don't regular CO2 generators burn natural gas?

Wouldn't they put off CO also?

The only time I spend in the room is about 15 minutes to water as of now.

I understand the danger of CO poisoning, but how does a regular CO2 generator burning natural gas not produce CO?

 

[Shady Smoka]

I wouldn't mess with with vent honestly. You could mess up the draft and end up venting everything into your house. It's really not a safe option IMO. Be careful.

 

[guest2012y]

It would suck to read this in the paper,.........."Man found dead when he tried to use the exhaust form his water heater to grow marijuana, apparently the gas had leaked into the rest of his home. Yes you heard right folks,that plague of a plant upon our society, MARIJUANA!!" Don't mess with it Sam,we don't need to lose anyone this way. I lost an uncle who was on a hunting trip in his camper using propane to heat it,he passed out and it killed him.

 

[Sam the Caveman]

The grow room is not in my house, its in the attic

 

[John Denco]

I don't understand chemistry well, but carbon mono-oxide and carbon di-oxide can be pretty close chemistry wise. In our state we lose people to carbon monoxide each winter. No one is trying to rain on your idea, just that we are a community of growers that cares about its members. BTW, a friend of mine tried this and found that he got a really minimum amount of CO2, not enough to make a difference. Plus, frankly, if this was such a great idea, don't you think we would have about 50 posts and threads on the subject?

 

[Avenger]

Carbon monoxide is produced from incomplete combustion. If the appliance has any yellow or orange color to the flame then it is not suitable for CO2 enrichment.

CO2 generators are not immune to carbon monoxide production, but they are less likely to produce monoxide because there is no restriction of the "flue" gases. So sooting and fouling of the burner orafices is less likely.

Gas water heaters and furnaces are using the heat from the burning of the fuel to heat water or air, so the flue gases are cooled before or as they make their way out of the appliance. This cooling of the flue gases is what causes sooting and fouling of the burner orafices and leads to incomplete combustion and carbon monoxide production.



Everything you might want to know about CO2 enrichment:
http://www.omafra.gov.on.ca/english/crops/facts/00-077.htm

 

[Danseur]

JD brings a good point about co and co2 being close on the chemistry side. The difference is an O. The efficiency of the gas hot water heater will determine the amount of co produced in relation to co2. Both co and co2 are gasses made by the combustion process, and if backdraft start to develop or exhaust is not proper the fresh air supply can get tainted and carbon monoxide will be produced in higher quantities as the extra O from the needed fresh air is not available to make co2 during combustion.

CO is produced in your hot water heater if you can notice soot residue around the exhaust work flue or chimney. That will be a sign that the gas water heater is not operating 100% efficiently, most do not.

"Carbon monoxide is produced whenever a fuel such as gas, oil, kerosene, wood or charcoal is burned. The amount of CO produced depends mainly on the quality or efficiency of combustion. A properly functioning burner, whether natural gas or liquefied petroleum gas (LPG), has efficient combustion and produces little CO. However, an out-of-adjustment burner can produce life-threatening amounts of CO without any visible warning signs.

When appliances that burn fuel are maintained and used properly, the amount of CO produced usually is not hazardous. But if appliances are not working properly or are used incorrectly, dangerous levels of CO can collect in an enclosed space." http://www.ext.colostate.edu/PUBS/consumer/09939.html

Perhaps look into a catalytic converter. Above all be safe Sam.

Accepted level of carbon monoxide is 0 ppm, while 30 ppm can give symptoms of flu within 8 hours or less. Very toxic stuff, be careful Sam. Also if small amounts of co are being released, a lung room just outside of your growspace could be used to capture and then vent so it is not able to get into your living spaces where humans or pets are. Plants do not live on the same toxicity level as humans or pets with regard to co, although again without that fresh air and available O, it can not oxodize during photosynthesis. (don't quote me on that last part, not a chemist armchair at best)

I think fresh air is the factor, for efficiency and health. Be well friend, take this with a grain of salt.

 

[nachohippie]

get a co detector just like a smoke detector hell put one of those in there too

 

[ShroomDr]

get a co detector just like a smoke detector hell put one of those in there too

BINGO

 

[guest2012y]

I'm not reading through this thread again.......but did anyone mention that co2 and co are heavier than air? It floats to the bottom of your room. Attics...basements....not good news.

 

[Lazyman]

If it needs more, I'll turn up the hot water heater.

I don't think the co2 ppm will get up very high on the setting it is on now. I do plan on testing it with one of those tester kits once it gets up and running and then adjusting it from there where it needs to be or as high as I can get it.

It should get higher than the regular indoor co2 levels.

You would have a 120V electric solenoid valve on a hot water line, and a motorized sheetmetal damper on the heater exhaust (preferably two, one N/C one N/O on a sheetmetal y) and wire them all to a CO2 ppm controller.

Add 120V, and the hot water valve opens, dumping hot water down the drain. The duct leading outside closes, and the one leading inside opens. No fans please, they affect combustion.

Be careful and use high temp tape and such. Make sure everything that gets hot is metal and only touches metal!

 

[big ballin 88]

If theres even a chance of it ending back up in the house is in really worth the risk? i mean we all love our plants and everything but is a little co2 worth the benefit of possible failures?