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Vacuum Toilets
An Evac vacuum toilet uses only 1.2 litres of water per flush and requires no electrical connection at the toilet itself. Its small-bore pipework and freedom from conventional drainage gradients make it particularly suitable for high-footfall buildings, refurbishments and projects where traditional gravity drainage would be difficult or disruptive to install.
What Is a Vacuum Toilet?
A vacuum toilet uses negative air pressure to remove waste from the toilet bowl and transport it through a sealed pipe network. Unlike a conventional toilet, it does not rely on a large volume of water and gravity to carry waste towards the sewer.
When the flush button is pressed, a valve briefly connects the toilet bowl to the vacuum drainage system. Atmospheric pressure forces the contents of the bowl into the pipework while a small amount of water rinses the surface. The waste is then transported through the vacuum pipe network to a central collection unit before being discharged into the sewer.
The complete process takes only a few seconds and uses approximately 1.2 litres of water.
Vacuum Drainage Solutions
The Evac Vacuum toilet is environmentally friendly having low water consumption, only 1.2l/flush.
The toilets are of non-electrical type. This means that it is controlled pneumatically with vacuum from the vacuum pipework system. Once the flush button is pushed, a pneumatic signal is sent to the control mechanism, which opens the discharge valve by allowing vacuum from the pipework system to enter the discharge valve diaphragm thus connecting the bowl to the vacuum system. Air at atmospheric pressure then forces the sewage through the discharge valve and into the piping. Simultaneously the water valve opens, and pressurised rinse water cleans the bowl. This whole operation is performed using just vacuum, NO electrical connections are required. Toilets with a vertical riser pipe of over 2m will require an Evac Non-Return valve at the top of the riser.
One common misconception is the aesthetic of the Evac vacuum toilet designed for buildings. Many people will immediately think of a stainless-steel bowl and the noisy action as seen on aircraft. The style of toilet used within the building sector is white porcelain and looks and feels like a conventional style toilet. In most cases, the user doesn’t even realize that it is a vacuum model.
Benefits of Evac Vacuum Toilets
Significant water savings
Evac vacuum toilets use only 1.2 litres of water per flush, compared with approximately 4–9 litres for many conventional gravity-flush toilets. This can reduce flushing-water consumption by up to 90%, particularly in busy commercial buildings with hundreds or thousands of daily uses.
Reducing water consumption can also lower the amount of wastewater entering the drainage system, helping businesses reduce utility costs and support their wider environmental targets.
Greater freedom when designing a building
Conventional drainage requires sufficiently large pipes installed at a continuous downward gradient. Vacuum drainage is far more flexible because wastewater can be transported horizontally and lifted vertically where required.
This allows toilets to be positioned in areas that would otherwise be difficult to connect to the existing drainage system. It can also reduce the need to excavate floors, create new service risers or make extensive structural alterations.
Smaller pipework
Improved hygiene and odour control
The rapid vacuum flush removes waste, air and aerosols from the toilet bowl into a closed pipe network. This helps limit the spread of odours and airborne particles within the washroom.
Because the pipework is maintained under negative pressure, damage to a pipe causes air to enter the system rather than wastewater leaking out into the surrounding building.
No cistern required
Suitable for new buildings and refurbishments
Vacuum Toilets vs Conventional Toilets
| Feature | Evac vacuum toilet | Conventional gravity toilet |
|---|---|---|
| Water per flush | Approximately 1.2 litres | Commonly 4–9 litres |
| Method of waste transport | Negative air pressure | Water and gravity |
| Drainage gradient | No continuous downward gradient required | Continuous fall normally required |
| Pipework | Smaller and more flexible | Larger soil and waste pipes |
| Cistern | Not required | Usually required |
| Installation flexibility | Can route around obstacles and lift waste vertically | Restricted by drainage position and gradient |
| Leakage behaviour | Air enters damaged vacuum pipework | Wastewater may escape from damaged pipework |
| Best suited to | Commercial, high-footfall and complex projects | Straightforward conventional installations |
Where Are Vacuum Toilets Used?
Vacuum toilets are particularly effective in buildings with high water consumption, complex layouts or restricted access to conventional drainage.
Common applications include:
- Offices and commercial developments
- Hotels and resorts
- Hospitals and healthcare facilities
- Schools, colleges and universities
- Airports and railway stations
- Supermarkets and shopping centres
- High-rise buildings
- Historic and listed buildings
- Laboratories and specialist facilities
- Stadiums, arenas and exhibition venues
- Building conversions and refurbishments
They can also be used in basements, temporary facilities and other locations where it is difficult to achieve the gradient required for traditional drainage.
Are Vacuum Toilets Only Used on Aircraft?
One of the most common misconceptions is that vacuum toilets are only suitable for aircraft, trains and ships. Although the technology is widely used in transport, modern Evac vacuum toilets are specifically designed for use in commercial buildings.
Building models are manufactured from high-quality white vitreous china and are available in wall-mounted and floor-mounted configurations. They look and feel similar to conventional toilets and can be supplied with options including soft-close seats, white or chrome buttons, automatic flushing and contactless infrared controls.
The flush produces a short vacuum sound, but the experience is different from the louder stainless-steel toilets commonly associated with aircraft.
The vacuum toilet mechanism is all contained within the confines of the toilet bowl; there is no toilet cistern therefore the void behind the toilet can be receded to 150mm.
The Evac Vacuum toilet has a variety of options including, Soft Close Seat and lid, Chrome or white flush buttons, Auto Flush, or Contact less Infra-Red flushing.
The toilet bowl is equipped with safety air intake, which secures the air intake in case the bowl is totally covered. Manufactured by: – EVAC. Optima 5.
- The bowl is manufactured in high quality vitreous china, either wall or floor mounted.
- Each toilet will be fitted with a vacuum breaker backflow prevention device.
- The push-button is to be located in accordance with Evac instruction sheets.
- The installation shall be conducted in accordance with Evac instruction sheets.
The water supply shall be connected in accordance with local regulations. This may require a dedicated Cat 5 water supply, particularly if using recycled water. The water feed for the vacuum toilets must be supplied at 3 bar
Is a Vacuum Toilet Suitable for Your Project?
A vacuum toilet system may be particularly suitable where:
- Reducing water consumption is a priority.
- A project has BREEAM or other sustainability targets.
- Toilet facilities are used by large numbers of people.
- Conventional drainage cannot achieve the necessary gradient.
- Existing floors cannot easily be excavated.
- Toilets need to be positioned away from current drainage stacks.
- A historic building is being refurbished.
- Space within risers and ceiling voids is limited.
- Hygiene and odour control are especially important.
- Future changes to the building layout are likely.
The suitability of a system will depend on the number of toilets, anticipated usage, pipe routes and available plant space. EVDS can assess these requirements during the early design or specification stage.
Vacuum Toilet FAQs
How much water does a vacuum toilet use?
An Evac vacuum toilet uses approximately 1.2 litres of water per flush. This is considerably less than the volume used by most conventional gravity toilets and can provide substantial savings in high-footfall buildings.
Does a vacuum toilet require electricity?
The individual Evac toilet does not require its own electrical connection. Its control and discharge mechanisms are operated pneumatically using vacuum from the pipework. The central vacuum plant used to generate and maintain the system vacuum requires an electrical supply.
Do vacuum toilets need a cistern?
No. Evac vacuum toilets do not require a conventional water cistern. A small quantity of pressurised rinse water is supplied when the toilet is flushed.
Are vacuum toilets noisy?
A vacuum toilet produces a brief and distinctive sound as the discharge valve opens and waste is drawn into the pipework. Modern building models are designed for commercial environments and the flush only lasts a few seconds.
Can vacuum toilets be fitted in an existing building?
Yes. Vacuum toilets are frequently used in refurbishment projects because their smaller pipework can be routed horizontally, vertically and around existing obstacles. This can reduce the need for extensive excavation and structural alterations.
Can vacuum toilets be installed above or below the existing drain?
Vacuum technology can transport wastewater horizontally and lift it vertically within the limits of the system design. This gives engineers considerably more freedom than a conventional gravity drainage system.
What happens if vacuum pipework is damaged?
The pipe network operates under negative pressure. If a pipe is damaged, air is drawn into the system rather than wastewater leaking out. The resulting loss of vacuum can then be identified and investigated.
Do vacuum toilets require maintenance?
As with any commercial drainage installation, routine inspection and maintenance are recommended. EVDS can provide technical support, replacement components and original Evac toilet spares.
Are wall-mounted and floor-mounted models available?
Yes. Evac vacuum toilets are available in different configurations, including wall-mounted and floor-mounted vitreous-china models. The most appropriate option will depend on the washroom layout and project specification.
Can recycled water be used for flushing?
Recycled or alternative water supplies may be suitable, subject to the system design and applicable water regulations. A dedicated Category 5 water supply and appropriate backflow protection may be required.
Speak to a Vacuum Toilet Specialist
Whether you are designing a new commercial building or exploring alternatives to gravity drainage for a refurbishment, EVDS can help you assess the most suitable vacuum toilet system.
We work with architects, M&E consultants, contractors and facilities teams throughout the UK, providing technical guidance, product selection and ongoing system support.
Call EVDS on 01634 684779 or contact our team to discuss your project.