Hospitals provide a variety of healthcare and domestic services for patients, visitors, and staff. As a result, water is used throughout many areas of the facility including heating, cooling, irrigation, domestic, food service and others. In addition to this wide-ranging usage, healthcare facilities also use water in unique ways such as sterilization, film processing, and for specialized laboratory equipment.
Conduct a water use survey
- A water use survey identifies the quantities, characteristics, and uses of water at the site. From the water use survey a water balance can be created which will help the water efficiency team decide where to focus their efforts.
Sterilizers and Autoclaves
- Sterilizers and Autoclaves can account for as much as 10% of hospital water use. This high amount of water use is due to the large number of machines, their continuous availability, and often the inefficient design of older equipment. Depending on the age and design, these units can use between 1 and 3 gallons per minute.
- Measure discharge flow rates – Ensure that unit discharge does not exceed the manufacturer’s recommended rate.
- Retrofit units with solenoid operated valves – These valves can shut the unit off when not in service.
- Replace old inefficient units with new efficient models – Newer units are designed to recirculate water and shut the machine off when not in use.
- Use a small expansion tank to cool water – Install a small expansion tank to allow steam to cool to temperatures acceptable for discharge to the sewer system. (Make sure modifications do not effect sterilizer operation).
- Reuse cooling water or steam condensate – As an alternate to replacement or retrofit consider directing the discharge water to cooling towers or boilers.
- Shut off all units when not in service.
- Install a tempering device for steam sterilizers - This device regulates the flow of cold water required for steam condensate discharged to the sewer. Savings of up to 50 gallons per hour per unit have been reported.
- Water is primarily used in the rinse or wash cycle and in older machines the water can run continuously. At larger facilities, x-ray processors may be on 24 hours a day, using from 0.2 to 4 gpm. These machines may also be continuously feeding water through the developing process even when they are not actually developing film. X-ray processing can account for roughly 6% of hospital water consumption.
- Consider retrofitting existing equipment with re-circulating devices – These devices can cut water use by 99%.
- Reduce flow rate - Limit water flow to the minimum rate needed to meet quality requirements. Some machines consume 3-4 gpm or more when a reduced flow rate would suffice. Installing an inexpensive flow rate meter in the unit’s supply line will help ensure the correct flow rate. Post the minimum acceptable flow rate near each machine.
- Install solenoid valves that turn off rinse water when the machine is not in use.
- Route final rinse water to serve as makeup for developer/mixer solution – Final rinse water usually has very few contaminates and in some cases can serve as the feed water for the initial developer/mixer solution (Check with manufacturer).
- Look for processors with squeegee equipment - This equipment wipes excess fluid from the film and can reduce the amount of chemicals transported between tanks by up to 95%, reducing the amount of wash water needed.
- Use regulating valves to limit the flow rate of wash water to the minimum needed to maintain proper quality.
- Water-cooled instruments and washing can account for the majority of water use in laboratories.
- Avoid single-pass cooling of laboratory instruments - Use the facility’s recirculating or chilled water system instead.
- Replace older single-pass cooled pumps with oil-cooled models
- Install air-cooled ice machines – Machines that use single pass cooling water for their condensers can use 10 times as much water as air cooled units.
- Use a mop and bucket or a broom – Cleaning surfaces with a mop and bucket or a broom is much more efficient than using a hose. If hose use is unavoidable, use a high pressure nozzle with an automatic shut-off. A high pressure water broom may also help reduce water consumption.