View Full Version : odor control

08-27-2009, 04:35 PM
which is better ozone or charcoal filters? I never heard of ozone, are they ok to keep in the same room with the plants? how do you set up a ozone generator? like the ones bettergrow hydro sells. It looks like odor can be a big problem for indoor grows. WHEWW!

David G.
08-31-2009, 01:41 PM
Both can work well, it just depends on how the grow room is setup. Generally speaking, ozone is only used as part of the exhaust system, while carbon filters can also be used to recirculate the air as it scrubs. Carbon is far more popular, but more and more growers are turning towards ozone, especially those who need 100% odor control, are able to use it as part of their exhaust system, in situations where the exhausted air isn't blowing directly into somewhere where someone will be breathing it (i.e. it should exhaust outside of the building through a port where people won't normally be within several yards, or it can exit the roof, etc.).

09-05-2009, 09:11 AM
Thanks Dave for the reply, So, how do you set up one of these ozone generators? Do you use a inline fan and push the air in the room thru the ozone generator and out the room on the other side with ducting?

09-08-2009, 01:57 PM
ozone is not something you want to breath in high concentrations for prolonged periods of time.

with in-line ozone generators, you usually attach it to the beginning of the exhaust end. you want the ozone to have as much contact time with the exhaust air as possible (while in the duct work) so it has time to destroy the odor molecules.

David G.
09-08-2009, 09:10 PM
That's right. Simply attach it to the exhaust fan and (preferably) allow a few feet or more of ducting before it exits the building to act as a mixing chamber. You have to make sure that the fan CFM doesn't exceed the rating for the ozone generator, otherwise the concentration of ozone in the exhaust air will be too weak to eliminate the odor.

If you need assistance choosing which ozone generator you need for your application, just let me know the size of the grow room and which exhaust fan (if any) you currently have and I'll help you out.

09-10-2009, 06:14 PM
Thanks David, I am not quite there yet on the room and fan, but, leaning to ozone instead of charcol. I will definitely get in touch when I make the decision. Micro.

10-01-2009, 03:47 PM
hi i have a 17ft by 17 ft grow room im not sure what the cfm is on my fans they are 10 inch i think they might be 1000 and there are 3, at the moment im using 3 carbon filters but they are not very effective. if i chose to use the ozone generators bearing in mind i need 3 exhaust fans for heat control would i need 3 generators and what size would i need for my room. your advice would be greatly appreciated.

11-08-2009, 03:28 PM
So just for clarification, ozone exhaust should not be exhausted into a room inside a structure. It shoud only be vented to the outdoors. Is ozone toxic to humans? Thought it was a product of oxygen? Any thoughts on the matter would be helpful

11-10-2009, 02:10 PM
I have used it but stopped when I couldnt tell the difference. My guys stunk to high heaven but I changed their diet and now I have no problems. IMO bi odor is just a waste of money.

But if it works for you use it

David G.
11-14-2009, 11:49 AM
Sorry for the delay in posting this reply to the guy with the 17 x 17 room (and sorry for the orange color; I couldn't figure out how to change it to black...):

David G, has asked me to jump in here. By way of an introduction, I have been manufacturing ozone units for Hydroponics since 1999. Before there were carbon filters available for exhausted air treatment.
I have worked with ozone for water purification since 1993.
Ozone is extremely effective at eliminating exhausted garden odor. Additionally it may be used for pest control.
Sizing an inline ozone unit, for an indoor garden, is the most frequently asked question.
First of all, square footage is no guide to determining the amount of odor treatment required. Square footage, in and of itself, does not produce odor.
The variety and number of plants is a better gauge of how much odor treatment a gardener requires.
The easiest method for determining this, is the amount of grow light wattage you are using. The more wattage, the more odor.
Ozone works best when it has plenty of "contact time". ie, the more time the ozone "sees" the odor the more effective it is. This contact time can be improved in a number of ways.
1. Increase the length of your exhaust ducting. The longer the ducting before the exhausted air exits to "atmosphere", the more time the ozone has to mix and eliminate the odor. The greater the fan cfm (1000+) the longer the ducting required. As a starting point I use 20' of corrugated aluminum duct. Use the "sniff test" to determine whether more ducting length will be required. Mounting an ozonator directly where the odor exits the garden (no ducting following the ozonator) does not
leave enough mixing time. The results would be extremely disappointing.
If a gardener has limited space or room size for great lengths of ducting, coiling longer lengths of ducting and hanging it on the wall a coiling it on the floor will help.
2. You can shorten the ducting by exhausting your garden into an attic or crawl space. This creates a fantastic mixing chamber. The ozone will eliminate the odor as well as eliminate any pests that use these two locations to breed.
3. No attic? Building or creating a an "atmosphere chamber, inside or outside your grow space, may serve the purpose. Using a sealed closet or building a box to discharge the the exhausted air into, before it is exhausted to atmosphere (outside) makes for a good mixing chamber.
In general terms, a 12 inch Big Blue will work for a 1000 watt reflector. As you may have deduced, creating a mixing chamber or exhausting into the attic, may reduce the size or number of ozonators (amount of ozone produced) and exhaust ducting required.
The single most important phrase for determining sizing?
Contact Time.