Flow control outlets for hospitals
Flow controlled outlets for tapware and showers, along with more efficient toilets have become an imperative. However, one major challenge is within the health care industry, where some desired constraints may be either impractical or not feasible.
Healthcare centres are among the biggest water consumers in Australia, with government estimates putting their daily consumption in Sydney alone at a staggering 21 million litres everyday. Medical and industry experts attribute this high water consumption to the prevalent use of water as a sanitising agent throughout the healthcare system.
Research published by the South Australian Health Commission in its Guideline for Infection Control in Healthcare Facilities document shows that with patients and staff susceptible to infection and disease, hand washing has been proven as the most important and basic sanitisation technique to prevent the spread of infection.
Accordingly, there are a number of hand-washing methods to ensure that proper sanitisation is achieved. The problem with these methods is that they do not take into consideration the amount of water required for this vital function and, as a result, the process may be seen by the uninitiated as unnecessary or simply wasteful.
The result can be – as has been recently muted – to simply mandate minimum flow rates at hand washing fixtures in an effort to be seen to be water efficient without due consideration of such an action. For example, some critical surgical hand washing procedures take up to five minutes to complete, and with the standard flow rate from water outlets in health care facilities being around 9L/min, this equates to approximately 45L being used in a single wash. Is this excessive given the risk?
Some sectors of the building industry heavily influenced by Green Building targets have expressed the need for healthcare facilities to further curtail their water usage and become even more water efficient. What has been intimated is that they would prefer new projects and buildings to be installed with fixtures and outlets that help conserve greater amounts of water than what may be practical or clinically proven as acceptable, especially when the consideration of cross infection control is factored in. In several instances these fixtures have been provided targets around 4L/min in an effort to simply reduce water consumption.
Ideally this would be a perfect solution, but reducing flow rates could lead to more problems than anticipated, as Enware Australia’s Group Technical and Innovation Manager Tim Fisher points out. “What we’re seeing are targets attempted to be enforced upon health care facilities with all good intention in an effort to conserve water, however a significant flow rate reduction without due consideration to the possible negative impact on cross infection control procedures of which hand washing is agreed to be the primary method of cross infection control in health care facilities should be validated through clinical data before implementation.”
While lowering water usage is desirable, controlling infection takes precedence for hospitals as otherwise they could potentially be facing a situation where infection rates spiral out of control!
Additionally consideration must also be given to the desired flow stream type demanded by the healthcare facility. It is generally considered that laminar flow outlets are used in lieu of aerated outlets for clinical hand washing, as laminar flow does not draw ambient room air into the water stream, avoiding any possible introduction of airborne bacteria.
Both of these technologies have limitations as to the minimum flow rate at which they perform, which in reference to Neoperl PCAs is 5 l/min. Therefore through prescriptive application of significant low flow rates, laminar flow outlet technology that is considered standard for these clinical applications is unavailable.
Further we must also then look at the heated water source that shall supply warm water to these fixtures within healthcare facilities. Enware’s Aquablend range of thermostatic mixing valves (TMVs) is considered to be the leading brand in healthcare within Australia.
TMVs are the preferred source for delivering controlled temperature heated water in healthcare facilities and in NSW may only be substituted where a cost advantage can be demonstrated after consideration of capital cost and maintenance routine costs are taken into account according to NSW Health’s Engineering Services and Sustainable Development Guidelines. TMVs as mechanical devices have a minimum flow rate of 4 l/min at which they must comply with AS4032.1 – 2005. This value then becomes the benchmark for minimum flow rate settings at fixture outlets where stable temperature warm water is required to be delivered.
What is highlighted here is that guidelines from State Health departments, plumbing codes and environmental design parameters from within Green Building, which whilst all recognising the need for greater levels of water efficiency, cannot be viewed in isolation as these technology combinations, together deliver warm water for clinical hand washing applications and require a level of compatibility.
According to Tim, greater levels of water efficiency can be significantly influenced by technology such as electronic or self closing tapware that also controls the time a fixture runs without the need for manual intervention to shut off the supply which has a significant impact on water usage other than simply reducing flow rates.
“Looking at flow rate alone does not have an impact on the duration a person uses a manually operated fixture outlet, therefore we need a combination of flow rate, we need time control and when implemented according to the application need and actual number of usages at those facilities or fixtures within a day will provide far greater efficiency gains.”
When these factors are considered it becomes obvious that amending flow rates alone may not have the desired impact in seeking water efficiency gains and that a comprehensive overhaul and greater level of understanding of the interplay of the technologies and clinical handwashing requirements is needed. As designers and builders look to obtain a ‘green-star’ building ratings in healthcare establishments, simply ignoring vital cross infection control considerations of the intended facility cannot occur without increasing risk.
With these problems facing manufacturers and designers, their concern over possible mandated minimum flow rates without due consideration of all factors is understandable.