A German company called SOG make a small ventilation attachment to fit on to the Thetford toilet cassettes to remove any smells/odours from the cassette to the outside of the vehicle. Whilst the toilet/shower has been fitted with an extract fan which switches off when the Thetford toilet hatch/shutter is opened, there was a tendency for smell/odours to escape from the cassette in to the toilet/shower, and due to the chemical additives added to the cassette, these smells/odours tended to hang on to any visitors not nice. To avoid this problem, a negative pressure needed to be established in the cassette which is achieved by adding an extract fan directly on to the cassette and venting these 'fumes' to the out side of the vehicle. Additional benefits of the cassette ventilation is that there is no longer a need to use chemical additives which only 'mask' the cassette content smells.
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But itīs all right now, I learned my lesson well.
You see, ya canīt please everyone, so ya got to please yourself
Ricky Nelson
fitted one in my motorhome works great no smell in toilet compartment but a bit of a pong when emptying.Do not use chemicals when you open flap on thetford it draws oxygen in with the fan on the outside, breaking down contents
Although I have toyed with the idea of fitting one certain things spring to mind. First the cost Ģ90, to work it needs 12v power, which could let you down. No chemicals for the holding tank are needed but a carbon filter needs replacing on the outside vent at a cost of Ģ8 every 12 months or so. Apparantly the weight of the full cassette is heavy to take and empty and less pleasent due to no chemicals to mask the obvious. So to my mind if one is going to places for long periods where no supplys of chemicals are available it would certainly be an option. You can certainly buy a lot of chemicals for the purchase of the system and filters. kiev
Ours had a SOG fitted when we got it. We still use a small amount of chemical to mask the odours when emptying. We get no chemical smell in the bathroom now because of the SOG, and I suppose the other advantage is that if we run out of chemical while away we have the SOG fitted. We empty every day anyway so doesn't have time to breakdown, mind you solids are usually deposited directly in the campsite toilets not via the cassette
We have a SOG fitted & wouldn't be without it. We don't like the smell of the chemicals or the smell they leave behind in the van. It permeates anything it gets near & it lingers.
We have no nasty 'niffs' left behind in the van after its use. It is emptied daily most days so is not heavy to transport to the disposal point. There are occasions we have been on sites which will not allow you to empty your cassette if you are using chemicals. On arriving home we empty the cassette & give it a good rinse several times. We allow it to stand in the garage with the cap off if necessary so the air has access although that is not very often. I dont mind emptying it whereas I would never empty one with chemicals init. We dont find it unpleasant to empty.
You dont need to change the filter every year. We are still using the same filter after more than two years. If you start noticing nasty niffs after the loo has been used then that is the time to change the filter.