Buzz
Airplane lavatories are compact spaces equipped with a toilet and sink, utilizing a vacuum-based flushing system. Stuart Dee / Getty ImagesIf you've read the Mytour article on How Toilets Work, you're familiar with my perspective. Toilets often get a bad reputation due to their purpose, but if you look beyond that and appreciate the engineering behind them, they are truly fascinating inventions!
A standard household toilet features a water-filled bowl. Flushing initiates a siphon effect, emptying the bowl. Gravity then transports the water to either a septic tank or the sewer system. For more information, refer to How Toilets Work.
The issue with this method on an airplane (or a train, bus, boat, etc.) is that the vehicle's movement prevents the use of a water-filled bowl—it would spill during even minor turbulence. Without a water-filled bowl, a siphon or gravity-based system cannot be used to empty it.
Aircraft lavatories employ an active vacuum system rather than a passive siphon, earning them the name vacuum toilets. When flushed, a valve in the sewer line opens, and the vacuum pulls waste from the bowl into a holding tank. This efficient process requires minimal water (or the blue sanitizing liquid used in planes) to prepare the bowl for the next user. Most vacuum systems use just half a gallon (2 liters) or less per flush, compared to 1.6 gallons (6 liters) for water-efficient toilets and up to 5 gallons (19 liters) for older models.
Vacuum toilets offer numerous benefits, even in standard settings:
- They consume very little water.
- They allow for smaller sewer pipes.
- They can flush in any direction, even upward. Since gravity isn't a factor, sewer pipes can run vertically without issue.
- The absence of downward pipe requirements eliminates the need for floor modifications when installing new toilets.
- They can be installed anywhere within a building.
These links will provide further information:
- Vestergaard Toilet Service
- AirVac Vacuum Toilets
- Microphor Marine Toilets
- How Toilets Work
- How Sewer and Septic Systems Work
- How Airplanes Work
- How do you replace a seal under a toilet?
- Why are they replacing all of the toilets in my apartment?
