Comparing vacuum and gravity drainage in buildings
Let us compare and take a closer look at the differences between the Jets® Vacuum Drainage System and the conventional gravity drainage system. Vacuum systems are becoming an increasingly popular alternative, offering a flexible and modern approach to building design, and are now used in high-end developments around the world. But before making a decision, it’s important to consider: what are the pros and cons of each system?
Grey water can easily be integrated into a vacuum drainage system by installing a grey water interface unit at sinks, showers or similar sources.
For sustainability however, source separation, using separate pipes treating different wastewater types separately, is recommended.
Vacuum systems support this approach, making it easier to transport and treat organic waste i.e. for biogas production.
Components
A Vacuum Drainage System consists of a Vacuumarator® pump with associated control panel, vacuum piping and vacuum toilets (VC™).
The Vacuumarator® pump is the most reliable vacuum generator available for vacuum systems. Greywater tanks can be used to connect washbasins, sinks or showers to vacuum drainage systems. Vacuum toilets are white porcelain toilets that look and feel like conventional WC pans. They operate with one single button, thus eliminating any confusion.
On the other hand, Conventional Gravity Drainage Systems use large diameter piping to ensure that wastewater flows away from the building by gravity. These systems require vent pipes to help maintain the proper flow of water and air which can lead to more complicated coordination, more structural penetrations, and pipework.
Sustainability
One of the main advantages of Vacuum Drainage Systems is their water efficiency. Vacuum toilets (VC™) use significantly less water per flush compared to conventional toilets, thus reducing water consumption.
In a typical office building, a vacuum toilet uses only 1 liter (or less depending on the toilet model) compared to a conventional toilet that uses between 4-6 liters per flush. This means that a vacuum toilet can save up to 57 million liters (about 15057804 gal) of drinking water throughout of the building's lifespan. This makes it an environmentally friendly option.
Hygiene
Vacuum toilets are known for their superior hygiene as they use a vacuum to draw the waste away and have lower risk when it comes to bioaerosol generation.
This means that the release of germs through the air causing disease or surface contamination is minimal on a vacuum toilet (VC) compared to a traditional gravity toilet.
Also, vacuum systems are completely closed, allowing no unwanted items or animals from the sewer to enter the toilet bowl.
Space-saving
Vacuum pipework is much smaller in diameter than gravity piping and horizontal runs of vacuum pipework can be installed flatter compared to gravity drainage.
Vacuum drainage pipework can be (is often) routed into ceiling void. This means that more space can be used for other purposes, and there is less need for additional vent pipes, making the coordination of pipework much simpler.
Vacuum Drainage Systems are a better choice when it comes to environmental sustainability, hygiene, and Return on Investment. It also offer greater flexibility in building design and are a more space-saving option.
Flexibility
Maximize the flexibility of the office space with connections from appliances in ceiling/floor voids and small diameter vacuum pipework routing, allowing for easy installation and retrofitting without affecting lower levels.
Connections from appliances can run in ceiling/floor voids to avoid running wet services in sensitive areas below or allowing for installation of appliances (kitchenette or tea points) in those spaces of the office area where there is no existing piping.
In addition, the small diameter vacuum pipework can be routed “up and down” to avoid ducts or structural beams. This flexible pipework routing means that additional/retrofit appliances can be positioned at virtually any location on the floor area and without implications for the lower levels.
A single central vacuum pump unit located at basement level and service of the entire building simplifies the maintenance process compared to potential multiple pumps service satellite kitchenette points in conventional systems.
Although many think the initial investment is higher, this often proves to be a more economical solution when all elements are considered (savings in water consumption, labor, and materials).
Investment and maintenance
Introducing Vacuum Drainage Systems, which despite higher installation costs for smaller systems, offer lower maintenance needs and fewer blockages than Conventional Gravity Drainage Systems.
The installation of Vacuum Drainage Systems can be more expensive than Conventional Gravity Drainage Systems for smaller systems, which can make it a less attractive option for some.
Although Vacuum Drainage Systems require less maintenance and would attract less blockages compared to Conventional Gravity Drainage Systems, they still need to be maintained regularly.