Hospitals have unique drainage challenges due to their special functions and environments:
Complex Wastewater Composition
Hospital wastewater comes from various sources and has complex components, including a large amount of toxic, harmful, radioactive, and heavy metal-containing wastewater. This type of wastewater must be collected separately and treated to meet standards before discharge; otherwise, it may cause virus transmission and environmental pollution1.
Complex Building Structures
Hospital buildings have complex structures and must comply with various specifications and functional requirements, resulting in numerous and scattered drainage points and a complicated piping system. This makes the design of the drainage system particularly complex and poses significant challenges to traditional drainage systems2.
Large-area Drainage Difficulties
Hospitals have extensive complex underground spaces, and drainage in areas above civil air defense zones cannot rely on traditional gravity flow, making sewage discharge difficult. Additionally, traditional methods using sumps and submersible pumps are prone to causing indoor air pollution, virus transmission, endangering maintenance personnel, and leading to difficult maintenance3.
Risk of Infection
Hospitals have a large flow of people, and patients' excreta contains many viruses. If water seal failure or sewage leakage occurs, viruses can easily enter indoor spaces, increasing the risk of virus transmission4.
An indoor vacuum drainage system is a drainage system that uses negative pressure for drainage, differing from traditional gravity drainage systems and pressure (positive pressure) drainage systems. It consists mainly of vacuum units, vacuum pipelines, vacuum toilets, and vacuum lifters56.
Compared with traditional systems, it offers unique advantages such as environmental friendliness, water conservation, good system airtightness, flexible pipe laying methods, and convenient and quick construction5.
| Aspect | Gravity Drainage | Vacuum Drainage System |
|---|
| Water Consumption | A water-flush toilet uses 6-9 liters per flush, leading to high water and treatment costs7. | A vacuum toilet uses only 1.2 liters per flush, saving 80% water and reducing costs89. |
| Sealing Performance | Relies on traps, which are prone to failure, causing odor backflow and virus transmission10. | Uses vacuum diaphragm valves (usually double valves); air is drawn in if sealed poorly, preventing odor leakage11. |
| Piping and Space | Requires sloped pipes, large diameters, and sumps, occupying space and increasing construction costs1213. | Needs no slopes or sumps, uses small-diameter pipes, offers flexible layout, and saves space and costs1415. |
| Floor Restrictions | Limited by upper and lower floor functions, restricting building layout22. | Free from inter-floor influences, allowing flexible building layout and easy modifications23. |
Reducing Cross-infection Risk
It is a fully sealed negative pressure system. During use, only air and space can enter, while bacteria in the pipes cannot escape, making it especially suitable for clean areas like operating rooms, negative pressure wards, and infectious disease buildings1617.
Clean and Odor-free Environment
The system's operation draws a large amount of air from the usage environment into the vacuum pipeline, removing odors, bacteria, and pollutants, creating a clean and odor-free bathroom system and improving the hospital environment18.
Superior Water-saving Capacity
Compared to traditional toilets using 6 liters per flush, vacuum toilets use less than 1 liter, saving over 80% of water. This is particularly beneficial for radioactive wastewater treatment in nuclear medicine departments, reducing decay tank volumes and radiation risks192021.
Flexibility in Construction and Renovation
Pipes are laid within the ceiling of the same floor, without damaging lower floors. It is ideal for hospital renovations, as it does not affect the operation of other departments2425.
Vacuum drainage systems are widely applicable in hospital construction and renovation, including:
Underground public areas and staff canteens
Radiology and nuclear medicine departments
Infectious disease departments and biological laboratories
Civil air defense spaces and large laboratories
Outpatient building public restrooms
Negative pressure wards2627428.
Project 1
Background: A 1,500㎡ third floor of a hospital, originally a physical examination center without sewers, needed conversion to internal medicine wards with 25 washbasins.
Traditional scheme: Required floor drilling, affected lower floors, occupied 2-3 parking spaces for equipment rooms, cost ~2 million yuan, 3-month construction32.
Vacuum scheme: Used one vacuum unit (12㎡ equipment room) and 25 terminal devices, with pipes in the ceiling, cost ~1 million yuan, 1-month construction33.
Project 2
Background: An 800㎡ underground parking lot area needed conversion to a canteen, office, and restroom without sewers.
Traditional scheme: Required raising the canteen by 300mm, building equipment rooms occupying 6-8 parking spaces, cost ~2.5 million yuan, 4-month construction34.
Vacuum scheme: Used a vacuum oil separator unit, with pipes laid under beams, cost ~1.5 million yuan, 2-month construction35.
Chengdu Sixth People's Hospital (Jinniu Campus)
Adopted vacuum drainage systems in underground B1/B2 areas, restrooms, and canteens to improve sanitation and reduce costs36.
Tongji Hospital (Optics Valley, Wuhan) Proton Building
Used Juchuan's vacuum drainage in nuclear medicine restrooms, featuring sealed operation to prevent radioactive contamination, flexible piping, and reduced wastewater volume. The project has been in operation since June 202337.
Hospital Vacuum Drainage Application Program.pdf