There is evidence to suggest that conservation only appeals to a specialist clientele, and there are reports, mostly anecdotal, of the opposite--for example, is the reported sale of used 3.5 U.S. gallon water closets real or merely an amusing after dinner anecdote based on a half remembered Washington Post article?
If water conservation is to become an explicit consideration in the purchase of domestic or commercial building appliances then perhaps there is a need for guidance on unit performance. Can this be a statutory requirement or merely voluntary or will market forces effectively ensure that manufacturers will participate? Similarly, once unit performance is publicly announced, will this provide a greater degree of consumer protection, possibly removing point of sale legislation, or will it introduce competitive advertising, currently not common in the U.K., where competitors performance may be compared to one's own product, an example being the flushometer tank advertising based around the ANSI drain line carry test results carried by this magazine?
As part of the U.K. government energy initiative, Eco labeling, or energy labeling, is now common for a wide range of domestic appliances including refrigerators, freezer, refrigerator/freezer combinations, washing machines, electric clothes dryers and combined washer/dryers and dishwashers, offered for sale. An example of the energy label which appears on appliances at the point of sale is shown in Fig. 1 and may be viewed at the U.K. Dept. of the Environment, Transport and the Regions' website at www.environment.detr.government.uk/energylabels/rw/index.htm.
Performance is linked to a letter grading running from A for the most efficient to G for the least. In addition, the label gives information on energy consumption per cycle for washing or spin drying performance and water consumption. Noise levels are also quoted on the label and washing and spin drying performance are again on a letter grade scale from A-G. Analysis of water use data, as illustrated in earlier articles in this series, identify showers and water closets as possibly the most appropriate targets for labeling. However showers provide particular problems, water use depends on line pressure and in the U.K. the majority of domestic dwellings still use in-building storage tanks to provide non-drinking water at very low pressure. In many cases showerheads in an upstairs bathroom may enjoy as little as 3 feet supply head. Mains pressure systems are becoming more common, as are pumped showers, however, low pressure gravity systems still predominate. Similarly, the acceptance and desirability of any particular shower might be determined by droplet spray pattern and other factors. Showers, therefore, are not a likely labeling target in the short term.
Labeling Water ClosetsWater closets on the other hand might be a suitable category for a water conservation labeling scheme. The 1999 U.K. Water Regulations have introduced drop valves, flushometer tanks and flush valve water closet flushing from January 1, 2001. Dual flush will also be reintroduced, i.e. the use of 1.6 U.S. gallons for a solid removal flush and up to 1.05 gallons for the removal of fluid contamination.
Therefore, it might be possible to set up a rating scale to represent the overall water closet water usage, based with dual flush on the experiential result that in general one full solid removal flush would be needed to every three fluid contamination removal flushes. The basis for the water closet acceptance into any such labeling scheme would have to be satisfactory compliance with the water closet acceptance tests that accompany the U.K. 1999 Water Regulations, details of which may be obtained from the Website www.environment.detr.gov.uk/wsregs1999/waterfit/index.htm.
Based on the best national practice, these acceptance tests, which were developed in conjunction with the U.K. Dept. of the Environment, Transport and the Regions by staff at Heriot-Watt University and Professor L.S. Galowin who was a Visiting Professor in this department during that period, include solid and fluid contamination removal, the solid removal tests being based on the German DIN standard and its Australian equivalent, while the fluid contamination removal tests require residual concentrations of no more than 1% and 6% following flush at full and dual flush levels. Details of these specifications may be obtained from the UK Dept. of the Environment, Transport and the Regions' Website already mentioned, and will apply to all manufacturers wishing to sell into the U.K. from January 1, 2001, when the current apparent restriction to trade represented by the U.K.'s previous insistence on siphonic flushing from the water closet cistern to the bowl, as described in this column in January 2000, is removed.
A Rating SchemeWhat form could such a rating scheme take? The recent establishment of the National Water Conservation Group, a voluntary coming together of interested parties into a potential pressure group led by the Building Research Establishment (BRE), the U.K. equivalent of the Built Environment section of the National Institute of Standards and Technology, and including water undertakers, plumbing organizations, manufacturers, both U.K. and overseas in view of the broadening of our regulations, will provide a basis for such a scheme. Further details of the current composition of National Water Conservation Group may be obtained from Martin Shoular at BRE, (e-mail address email@example.com).
The group's current thinking, which is still at the developmental stage and open to suggestions and information from other interested organizations, envisages an A-G rating based on the flush volume of particular units, for example A to E representing .55 to 1.3 U.S. gallon average flush volume with F at 2 gallons and G representing older installed units at 2.4 gallons, the overall average flush volume being calculated on the basis of 1 full solid removal flush to 3 lower volume fluid contamination flushes. (For example a 1.6 gallon full and 1.05 gallon dual flush water closet would give an average of 1.2 gallons per flush).
At present few entries are likely to reach to the A-C level, although Scandinavian water closets operating in a dual flush mode at 1.05 gallons and .55 gallons would score a 0.65 gallon average and it may be that flushometer equipped water closets using 1.05 gallons for both solid and fluid contamination could achieve a relatively high C rating . As these grades could only be awarded to water closets that passed the test specifications accompanying the Water Regulations, this would provide a degree of consumer protection and the A-G rating could be enforceable at point of sale, as it is for the Eco label range of appliances mentioned above.
Whether it will be possible or desirable in the future to include other performance criteria within the labeling might be an interesting area of discussion, particularly in view of the U.S. manufacturers' experience of competitive advertising based tightly around the results of test specifications. U.S. manufacturers or other interested groups considering an expansion into the U.K. market may well find further information on the National Water Conservation Group interesting.
Water conservation has to be seen as an integral part of a longer term energy and water conservation policy which would reduce the dependence on natural resources in many developed countries. At the same time it is necessary to ensure that developing countries gain advice and experience in moving to install systems that themselves are both practical and efficient. Clearly there are a whole range of challenges here for the engineering profession of which plumbing engineering is only one constituent.