How to Use an Ozone Generator
The proper use of an ozone generator depends in part on the amount of output of the unit. Some units emit only a small amount of ozone, so it is only a small factor in the overall air mixture in the room or home. These fall into the area of an air treatment/purification system. Manufacturers like to offer small version ozone generators because there is less chance of abuse or misuse. You will see room air treatment units putting out 400 to 700 mg/hr; which is too much for a closet, but not substantial in a good size room.
An ozone generator is a more serious machine when it tops 10,000 mg/hr of ozone output. This machine is not something to run quietly in the background. The first rule of a serious ozone generator is that they are used in vacated areas. You cannot (or should not) stay in the room or building when a sizable ozone generator is working. Just to keep the record straight, ozone is still just a enriched form of oxygen; but when produced at high levels ... it is a respiratory irritant. Ozone quickly dissipates back to oxygen when the machine is turned off, and the house is ventilated with fresh air.
To use an ozone generator, take the process is steps or layers. The impact depends on the size of the room or house, the humidity, the height of the ceiling, the movement of air, and the strength of the threat (odor, germs, or mold). So, the smart process would be to use something like a 20,000 mg/hr unit and run it for an hour or two. Then, judge the affect of that treatment. If something like a cat odor can still be detected, go to a 3 to 4 hour treatment, if needed.
We see people being advised to run the machine for 12 and 24 hours. This is very inconvenient since you must vacate the house. It also indicates that this is a too-small unit that has been over-sold in ability. Frankly, it is better to run ozone in 1 to 3 hour periods and do it in cycles to gradually erode the odor. This is particularly true of lived-in or embedded odors. After the ozone treatment has solved the first tier of odor problems, let the house breath for a day and try again. This allows the odors to come out and disperse when they encounter the ozone.
Use a timer to allow the unit to run for a cycle and then turn off so most of the ozone is gone by the time you return. It is always best to ventilate the house with fresh air anyway after you enter. If your unit doesn't have a timer built in, get an inline timer from a local hardware store.
For maximum effect, turn on the furnace fan so the ozone is spread throughout the house. This also treats smells and things in the duct work. Turn on ceiling fans, and place the ozone generator 3-4 feet off the ground.
If the weather is warm, be sure to turn on the AC along with the fan. Hot air hinders ozone production. High humidity also hinders ozone production.
Ozone will help alleviate pollen and allergens in the air. Ozone will kill mold spores and pollen, but the particulates will still be in the air. Therefore, if you are treating to reduce allergens, a once a week treatment (particularly in the bedrooms) is suggested. You may want to also run a HEPA filtration system to take out the particulates. You will find stand-alone HEPA filtration units in department stores like Kmart and Walmart.
If you are trying to kill mold, you need a high-output ozone generator that will run for 4-6 hours at a time. The 40,000 unit may be a better choice here. But, mold will return unless you also find the water source feeding the mold, and stop it. So, while ozone will kill mold and mold spores, the task to stopping mold from returning requires a hands-on approach to solve the water problem and getting mold infested materials out the the building.
Remove pets from the building during treatment. Ozone will not bother your fish. If odor is a problem, cleaning is always the first duty, so do not use ozone to treat for a badly-kept house other than an "Odor Knock Down" before you start.
Finally, do not take Internet hype at face value. Most Internet ozone generator promoters hugely over-sell their machines and misstate facts in their favor.