Vacuum Plumbing FAQ

How does it work

How does vacuum plumbing work?

The AcornVac® system uses differential air pressure to transport waste from plumbing fixtures, such as toilets, urinals, sinks, and showers, through a piping network to a central point from which waste is discharged into the facility's sewer or waste treatment plant. The vacuum center is the heart of the system. It controls the vacuum pumps to create vacuum pressure in the waste piping, allows incoming air to assist in drainage from the toilet when it is flushed, and empties accumulator tanks that collect wastewater from other sources. For more on how vacuum plumbing works, visit the What is Vacuum Plumbing? page

Hygiene Benefits

How does AcornVac vacuum plumbing contribute to improved hygiene?

With vacuum plumbing, a constant vacuum pressure in the waste piping system draws air into the toilet when flushed; this eliminates any splash or flush plume from the bowl as the wastewater is pulled into the piping system, thus reducing the spread of germs. NSF® testing confirmed no detectable overspray with AcornVac vacuum plumbing systems. For more on this and other health benefits of AcornVac vacuum plumbing systems, visit the Health, Safety and Welfare page.

Toilets

How does vacuum plumbing work with toilets?

When the toilet is flushed, the vacuum valve opens and positive air pressure moves into the bowl, carrying wastewater vertically into overhead waste piping, which leads to the vacuum center. For more on how vacuum plumbing works, visit the What is Vacuum Plumbing? page

Sinks, Showers, and Fixtures

How does vacuum plumbing work with sinks, showers, and other fixtures?

As waste drains from the fixture, it is temporarily collected at the accumulator. This accumulator can be designed inside of a standard 4” wall with 16” stud spacing or inside a fixture or fixture cabinet. As waste fills the accumulator, it sends a signal to the controller to open the extraction valve. When the waste valve opens, air is pulled into the accumulator and vertical piping, pulling accumulated waste out. The incoming air vertically carries the wastewater into the overhead piping and then into the vacuum center waste collection tank for discharge by gravity to the sewer system. For more on how vacuum plumbing works, visit the What is Vacuum Plumbing? page

Piping Network

What happens if the vacuum piping network develops a leak?

Since the piping is maintained under a continuous vacuum, any leaks that might develop will draw air INTO the pipes, preventing waste infiltration. The Acorn Vac Center is equipped with several alarm features that help alert maintenance personnel of any leaks that might develop in the vacuum piping network.

• For small leaks that lead to frequent pump cycling, an alarm will be generated indicating “Too Many Vacuum Pump Starts per Hour”.
• For moderate leaks that might keep a pump running continuously, an alarm will be generated indicating that the “Vacuum Pumps have run too long”.
• Should a major leak occur which causes the vacuum pressure to drop below minimum safety levels; the Vac Center will generate a “Low Vacuum Pressure” alarm. Since the vacuum piping network exists in the overhead structure, finding and correcting vacuum system leaks is easily accomplished. By comparison, leaking pipes in an underground system may go undetected for years, possibly contaminating the surrounding area or water table.

Piping Failure

What about a catastrophic piping failure – such as a pipe breakage due to an earthquake?

Unlike underground piping, a catastrophic piping failure, regardless of the cause, will be immediately identified and easily repaired.

Power Failure

Since the system uses electrically operated vacuum pumps, what happens if power fails?

Most facilities add the Vac Center to their standby power generating system. In fact, Acorn Vac offers a number of control features and hardware options to accommodate the unique needs of standby generator power sources. If the facility does not have a generator, or chooses not to add the Vac Center to the standby power source, the drainage system is simply not available until normal power is restored.

Fail-Safe System

How fail-safe is the system? Is there any redundancy built-in?

The AcornVac system is designed to provide complete redundancy on all primary Vac Center components. This includes dual collection tanks and multiple pumps to ensure that the system can continue to operate so long as electrical power is available.

When the Vac Center is operating on an emergency power generator, it is designed to switch the pump control strategy to a method that is most compatible with this power source. For those facilities with generators that have marginal capability for starting induction motor loads such as a vacuum pump, we offer electronic motor starters which minimize the inrush current of a pump as it is being brought on-line.

Large Debris

What happens when unusually large debris gets into the system?

Debris found to inhibit the performance of gravity drainage systems typically has little detrimental effect on the performance of the vacuum drainage system. In fact, items that would typically block a gravity drainage system will pass directly through the vacuum piping network to the Vac Center collection tanks due to the fact that they are assisted in their movement by atmospheric pressures entering the system in the course of normal operations. Vacuum drainage systems virtually eliminate clogged piping.

Spare Parts

Are spare parts available or should the facility carry spare parts themselves?

All parts are supplied by AcornVac and are available for immediate shipment. However, a local factory certified maintenance contractor will stock a quantity of repair parts for emergency purposes.

Roof Penetrations

Does the vacuum system need vents (roof penetrations)?

No, the vacuum system does not need vent stacks. Air removed from the piping network by the vacuum pumps becomes the vent for the system.

Maintenance Requirements

What are the recommended maintenance requirements?

The primary service requirements would be at the Vac Center. The vacuum pumps are equipped with a small cartridge filter that we recommend be changed every twelve months. The pumps also have a cooling coil that should be cleaned once a year. The AcornVac vacuum interface components have been tested to well over three million cycles without failure. These components have no regular required preventive maintenance. Should a problem occur with either a Controller or an Extraction Valve, the component is designed to be easily removed and replaced.

System Odor-Free

In a supermarket or hospital, is the system odor free?

Yes. Any gasses or odors which might exist in the Vac Center collection tanks are discharged when the tank is drained, and any gasses or odors that might exist in the piping network are contained therein by the normally closed Extraction Valve and removed by the condensate extraction process.

Vacuum Lift Piping

Can the vacuum lift piping or risers be higher than 22’?

Yes; however, the system must be engineered considering all load factors including anticipated activity and peak loads as well as diversity requirements. Call the AcornVac Engineering Department for design assistance.

Where are the valves

Where are the controller valves, check valves, etc. made?

Yes. Proper engineering ensures that the system is sized for such events.

Large Water Flows

Can the AcornVac system accept large water flows associated with multiple use scenarios, such as large office buildings or prisons?

Yes. Proper engineering ensures that the system is sized for such events, including large office buildings or prisons.