Toilets can seem like a taboo topic to discuss — after all, what we do in bathrooms is seen as one of our more private spaces. But when a question such as this comes up, people are willing to put aside the discomfort in favor of curiosity to find out: how do airplane bathrooms work?
Airplane Toilets vs. Traditional Toilets
Before we can get into how an airplane bathroom works, we need a quick refresher on how traditional toilets operate.
The average home toilet features a seat attached to a porcelain bowl filled with water. After doing your business, you flush the toilet, which causes the water to drain down and out of the bowl through the connected plumbing and back out into a sewer system or septic tank.
While this process works great for a stable space like our homes, on any transportation large enough to feature a toilet — planes, trains, etc. — the movement of the vehicle would splash sitting water right out of the toilet bowl. Which makes for a very inopportune experience. However, because there isn’t any water resting in the bowl, the normal flushing method (which requires water and gravity to form a kind of siphon) won’t work.
Due to this, airplanes use something called a ‘vacuum toilet’. When you flush, a valve inside the sewer line opens and sucks the content of the bowl back out into the line. From there, the waste is sucked into a tank until landing. The vacuum does the work that is mostly required from the water in a traditional toilet bowl: which just means plane toilets have to use less water or sanitizing liquid after each use.
This system uses significantly less water than our home toilets do — many vacuum systems flush with just half a gallon of water as opposed to 1.6 gallons used by low-flow toilets and up to 5 gallons used in older models.
So there you have it! Thanks for joining the S & D Plumbing team for Airplane Toilet 101. If you have any questions or concerns regarding the toilets in your home (Are they working properly? Can you be using less water?), give our office a call at (512) 648-4663 or contact us online.