By RV Daily,
February 18, 2025
In this article, we take the mystery out of the SOG toilet caravan ventilation system. Learn what it is, how it works, and if it really works to civilise your caravan toilet experience.
If you ask my wife what is her favourite feature of our caravan, she would probably say the toilet is high on her list. As I get older, I must admit I do appreciate not having to do the late-night dash to the amenities block for a quick pee before bed.
When free camping for extended periods of time, a toilet in the van is a much more civilised way of doing number twos. But there’s a problem, and there’s really no delicate way to put this. The smell of a man-sized turd can render the caravan uninhabitable for a good 20 minutes. Fortunately, we found a solution in the SOG toilet caravan ventilation system.
What is the SOG toilet ventilation system?
This brilliant device is so simple that it’s amazing it isn’t a standard feature on every caravan or motorhome fitted with a cassette toilet. The SOG kit comprises a small 12-volt fan that sucks air from the toilet bowl, through the cassette and out to the outside air, thus preventing any odours from escaping into your caravan.
You needn’t worry about your neighbours complaining about the stench being blown to their campsite as the expelled air is passed through a carbon filter, eliminating any odours.
There are several kits available to suit just about every cassette toilet system on the market. Make sure you take note of the type of toilet you have before purchasing a kit.
How does the SOG toilet ventilation system work?
The SOG toilet ventilation system works by the use of an automatic, high-performance fan that activates as soon as the toilet valve is opened, creating a vacuum effect in the waste-holding tank.
When the toilet valve is opened, fresh air is drawn into the tank, immediately pulling in any odours generated during use. These odours are then vented outside, preventing them from escaping into the living space. This inward airflow also acts as a natural seal, stopping any unpleasant gases from rising out of the tank.
When the valve is closed, the SOG toilet ventilation system shuts off the fan but continues to provide passive ventilation through an external vent in your caravan. This ensures a continuous supply of oxygen, which aids in breaking down waste more efficiently. Microorganisms responsible for decomposition thrive on oxygen and water, as they can only absorb nutrients when dissolved. By increasing the oxygen supply both during and after toilet use, the system accelerates the waste breakdown process without requiring chemical treatments.
A comparable principle is used in sewage treatment plants, where compressed air is introduced to sustain microbial activity and promote efficient decomposition. The SOG caravan toilet ventilation system applies this same concept to caravan toilets, ensuring a more eco-friendly and odour-free experience.
Can I install the SOG toilet ventilation system myself?
Installing the SOG toilet ventilation system in your caravan is a fairly simple DIY job for those who are handy. We won’t give you a step-by-step tutorial, as there are a few different options depending on your existing setup and toilet cassette brand. So you’ll need to simply read the instructions very carefully before beginning the task.
Being a German product, the instructions are written in translated English and some sections don’t make immediate sense. Fortunately, there are plenty of videos and guides online to refer to if needed. If you’re not confident, make sure to enlist the help of a professional to do it for you.
One vital step is to ensure you turn off your 12-volt electrical system before you start to cut into any wires. A short circuit here can damage the flush water pump and, in some toilets, these can be expensive to replace.
How do I use the SOG toilet in my caravan?
Once the SOG has been fitted, your toilet can be used exactly as you had used it previously. You can still use the toilet chemicals in the cartridge if you like, but there really is no need to, as the smells are no longer an issue. We still use a small amount of nappy sanitiser and a drop or two of eucalyptus oil just to make emptying the cartridge a little more pleasant.
Does the SOG caravan toilet ventilation system really work?
The SOG toilet ventilation system has made using our caravan toilet a much more civilised affair. It’s one of those things that you really don’t appreciate how good it is until you have one. At under $400 plus a couple of hours for installation, it’s not a ridiculously expensive modification by any means.
Words by Marty Ledwich and Jessica Palmer.
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I’ve had this system for 2 years. It’s great. But, what does S O G stand for ?
Hi David. The word SOG loosely translates to ”suction” in Germany and SOG is a german company. It refers to how it works by ‘suctioning’ and redirecting the air from the toilet when needed.