How Can I Vent Through The Sewer?

[SmokeyMacPot]

A common alternative to venting up the chimney is venting into the sewer pipe. Depending on how your house is built, if you push air into your sewer pipe, the air may travel up through your house sewer standpipe. However, it is possible to vent directly into the actual sewer system.

Venting into the sewer is generally safe. If someone is working in the sewer nearby, they might smell the sweet pungent aroma of your crop (Not likely at night), but they have no way to tell where on the block it is coming from. Since the pipes large enough to walk in are quite far away from individual homes, the smell has lots of time to dilute.

[Editor’s note: the stinky sewer will also hide your crop's odor up to a point. The sewer system itself is sealed, but you should check nearby manholes covers just incase for excessive blower noise and smell. The undeground sewer system will also remove and cool exhaust heat - excellent protection against infrared detection.]


To start you will need to locate your sewer pipe in your basement. This is the pipe coming from your toilet(s) on upper floors.

Near the basement floor, there should be a “Y” connection at an angle, with a cap on it. Some houses have metal pipes, other houses will have ABS or PVC plastic sewer pipes.


You will need a pipe wrench to remove the cap. Sometimes, if the house is very old, you will need to demolish the cap to get it off. You can buy a new one later at the hardware store if you need to.
This will reveal a hole 3 or 4 inches in diameter, depending on where you live, it may even be another size.

CAUTION: Fumes from the sewer can be poisonous, so make sure to use caution when removing the cap, and once a fan is installed, make sure to keep it ON all the time , so that there is no backflow into the home.

You will need to visit a hardware store, and pickup the various connectors and aluminum flex ducting to connect a fan to the hole. The most efficient fans for this purpose are centrifugal inline fans, but a squirrel cage fan will work too. The major difference is power consumption - an inline fan will use about 1/4 the electricity of the same size squirrel cage, they are VERY efficient, but a little bit noisier.


The fan here is 438 cfm, and only uses 115 watts. The inlet and outlet ports are 6 inches in diameter. I use a reducer from 6" to 4", and then I use 4" aluminum dryer ducting to the sewer hole, and of course plenty o' duct tape!

Once you are finished, you can test your work by standing outside the basement door, and holding a lighter to the crack at the bottom of the closed door. The flame should shoot inwards, because air is being drawn from the upstairs.

If you have successfully create this 'negative pressure' environment, there is no way that odorous grow room air can enter the house, hence the smell is contained!

[Editor’s note: the sewer contains methane – a smelly and potentially explosive gas! Keep those gases away from your water heater pilot light!]

Author: JonJaffer

[InhaledFreq]

Perhaps plug the fan into a Uninterrupted Power Supply to keep the basement from filling with sewer gas in the event of a power outage (especially if there is a gas heater or water heater located in the basement.)

[dirtyjerz]

I recently read an article in the paper that the goverment was going to put money into stopping people from dumping into sewer lines. Supposidly they said they had a way to find what house have a pipe rigged up to the sewer thats not suposed to be there.. again this is for people illegally dumping but i would be carefull.......

i do have related question... once the air is filtered by the carbon filter and leaves out the chiminey... is there any smell after going through the filter at all????

[BWC BayArea]

Just the faint smell of activated carbon that u could only catch a whiff of if u put ur nose to the edge. even I f ur filter "expired" I would think that molecules would dissipate so there would be no strong aroma by the time it hits ground level. Make sure U mask the light coming out of the chimney. U'll mess around and look like ur callin Batman, but I bet he's not the gonna be the 1 knockin on ur door. But I'm speaking theoretically. Filter + chimney exhaust = and the u can go on vacation and

[dirtyjerz]

thanks bay area! good point with the light comming out of the chimney.... seems like an easy precaution to forget about

[BWC BayArea]

Originally Posted by dirtyjerz

thanks bay area! good point with the light comming out of the chimney.... seems like an easy precaution to forget about

Don't thank me, thank our neighbors up north. Many a Cannuck (or so I've read) have had this problem drawing attention to their grows years back it was a common problem. I'm just passin on info. But ur

[exAkT]

ive been doing plumbing for a long time and all this makes perfect sense, and as far as i can think would work as said.

BUT

what happens in the event your sewer backs up?

I honestly think it would be worth the headache to get the sewers cleaned before the grow just to be safe....