Dialysis Clinics, USA
Dialysis clinics are a unique and growing segment within the healthcare industry. They present a set of specific challenges and benefits separate from those of other buildings.
Finding the ideal real estate locations to minimize the treatment impact on their patients’ lives is important for dialysis clinics. This can lead to either new construction or re-use of existing buildings, but if building conversion helps bring clinics even closer to their patients, most existing facilities are not designed around the unique and extensive drainage needs of dialysis clinics.
Installing the Evac vacuum system in the overhead can minimize or eliminate the need for x-ray, demolition of the building foundation, soil stacks, reworking existing mechanicals or extensive floor trenching and wall penetration. It overcomes the possible hassle with other tenants in mixed-use buildings when it is not feasible to cross the slab.
The Evac system also provides numerous operational benefits such as reduced water consumption, improved hygiene, space savings with smaller diameter piping and contaminated waste stream separation and confinement.
In a population where patients are at a much greater risk to illness, hygiene is critical. Because Evac vacuum toilets flush, with only 0.3 gallons – 1.2 liters of water and 16 gallons – 60 liters of ambient air, overspray with aerosolized feces is greatly reduced, aiding in the prevention of airborne infectious diseases.
- Intake of acidic wastewater
- High flow rate related to the reverse osmosis equipment
- Need for reliable system with high availability and redundancy
- Sound constraints for patient comfort in the facility
- Requirement for quick installation timeframe and building conversion
- Heat from sanitization process in dialysis machines
Project benefits from the Evac solution
- Reduction of potable water consumption with Evac toilets (0.3 gal. – 1.2 L per flush instead of 0.8-1.6 gal. – 3-6 L with a standard gravity toilet)
- Savings on construction costs compared to other solutions
- 3 to 4 weeks saved during construction, enabling the clinic to open on schedule
- Flexibility in piping routing without a constant slope and with smaller pipe diameter around existing mechanicals
- Enabled other construction trades to continue work simultaneously
- Complete system redundancy to ensure high availability
Overcoming the project constraints
The building drainage plan, as initially approved, was incompatible with the existing sewer infrastructure. Other options were investigated and compared to the Evac vacuum system, but they turned out to be more expensive and less reliable than the Evac solution. Design change and local approval were accomplished in 30 days while 3 to 4 weeks were saved on the construction schedule, notably because other trades could work simultaneously instead of waiting for the concrete to cure.
To overcome the constraints of the clinic layout, the plumbing was fabricated above the floor. The vacuum transports effluent through an overhead piping network to the vacuum collecting unit located in the mechanical room. Only one vent was needed, reducing the roof penetration requirements.
Evac’s EcoVac vacuum collecting unit was selected to provide full vacuum and discharge pump redundancy and the required availability with its buffer capacity of 210 gallons – 800 liters. The stainless steel tank offers high resistance towards acidic conditions and heat. The control logic monitors the system availability and operates the vacuum pumps on a lead-lag logic for surge capacity while it notifies the customer of any alarm or maintenance needs. This eliminates the need for a technician to be constantly onsite. The Evac vacuum interface units at the collection points feature enclosed buffer boxes to minimize the noise, specific materials selected for collection points in location at risk for high temperatures, redundancy for high flow conditions, and they do not require any electronic connection.
Increasing safety for patients and nurses
To demonstrate the hygiene of the system, tests were conducted by the NSF. The tests consisted in filling vacuum and gravity toilets with an E. Coli suspension and measured the overspray using an array of Petri dishes. Microbial analyses showed undetectable levels of overspray for vacuum toilets while standard toilets had measurable levels of bacteria on the toilet rim and floor.
The system easily accommodates waste stream separation and confinement for dedicated treatments, and in the instance of a pipe breach, the risk of leakage with a vacuum piping system is greatly reduced compared to gravity plumbing. This is because of the pressure differential which will suck air in instead of leaking water out.
Project specifications and challenges
- Existing mechanicals in the overhead mid-project
- Equipment’s ease of use with limited available technical staff on hand
- Not enough drainage pitch from the mechanical room to the sewer location (150 ft.-46 m away)
- Flowrate: 20 GPM – 114 L/ min
- 5 Evac elongated porcelain vacuum toilets
- 68 Evac vacuum interface valve kits for greywater buffer tanks and buffer pipes
- 10 Evac check valve assemblies
- 1 Evac EcoVac 175 collecting unit, includes a stainless steel tank, 2 vacuum pumps, and 2 discharge pumps with a 50 GPM – 190 L/min capacity