BEING WATER EFFICIENT

With underground water resources threatened by increasing consumption (water usage has doubled in the last 20 years), water supply is fast becoming an unpredictable, unevenly distributed resource.

Douglas Group's Bob Purdom highlights the key issues of water efficiency and hygiene.

He outlines product solutions available to those in the H&V sector and facilities managers in making the washroom environment a more installer friendly, user friendly, water efficient and safer place.

Despite the importance of water sustainability and increasing Government recognition of its importance, statistics still paint a depressing picture:

• Each one of us uses 70% more water than 30 years ago
• Thames Water leakage due to London's Victorian-built sewer equates to 300 Olympic-sized swimming pools a day
• UK drought condition - lowest rainfall for 85 years
• Currently some reservoirs are 12 feet below their expected levels

However, if everyone turned the tap off when brushing their teeth, collectively in one week we'd save enough water to fill the Millennium Dome.

Water efficiency

With our underground resources threatened by increasing consumption (water usage has doubled in the last 20 years), water supply is fast becoming an unpredictable, unevenly distributed resource.

Therefore, consumption habits must change. More effective water utilisation and waste reduction is essential.

Water companies are investing in improving the necessary infrastructure and reducing the hemorrhage of mains water losses.

Historically in the UK, we have used domestic water control product solutions in commercial applications where both usage patterns and user demands are quite different. This is in part related to the historical use of low pressure systems.

Today's building designers have a new set of design criteria for commercial buildings including:

• Modern, aesthetic styling
• User safety and comfort
• Proven design and product innovation
• Durability - long service life
• Water efficient - lowering water and energy costs - delivering value for money
• Buildability - simple to install and easy to use

Comfort and safety

Every year in Britain, approximately 20 people die and 600 suffer serious injuries resulting from contact with hot bath water.

This has been highlighted by the recent safety campaign 'Hot Water Burns Like Fire', led by Wakefield MP Mary Creagh and many leading children's charities.

Five seconds! That's all it takes to scald a child with bath at 60oC...

It's a common hazard.

At least one child under the age of five is taken to an A&E department suffering from serious scald injuries as a result of extremely hot bath water.

The problem is so prevalent that charities like CAPT (Child Accident Prevention Trust) and the CFBT (Children's Fire and Burns Trust) exist primarily to raise awareness of the potential dangers. The campaign web-site - www.hotwaterburnslikefire.org.uk - is well worth viewing, providing relevant information concerning this key safety issue.

A casual observer of the problem would probably offer a simple solution - why not reduce the temperature at which we store hot water? However, lowering the stored temperature increases the risk of Legionella - a naturally occurring organism that can cause Legionnaire's Disease:

• The bacteria grow and multiply between 20 and 45oC.
• At less than 20oC the bacteria remains a potential threat.
• Temperatures above 65oC eliminate the risk.

Water temperatures unable to cause scalding are ideal for the propagation of Legionella. Water temperatures that kill the Legionella bacteria will cause scalding.

Legionnaire's Disease

There are around 200-250 recorded cases of Legionnaire's Disease in the UK each year.

Legionnaire's Disease is normally contracted by inhalation of aerosol or vapour particles and approximately 50% of these cases are associated with overseas travel.

Main areas of risk include:

• Water system incorporating a cooling tower or evaporating condenser.
• Hot and cold water systems.
• Other water systems containing water above 20oC that may release water or aerosol droplets eg humidifiers, spa baths, indoor fountains, water features and car washes.

HSE Approved Code of Practice advice highlights:

• Maintaining good hygiene in the water system
• Storing hot water above 60oC.

It also provides guidance on other water treatments, such as biocides, chlorine dioxide, ionisation and the use of ozone and UV. For more information see HSE Approved Code of Practice & Guidance Document L8.

Safe HOT water temperature control

For over 25 years, thermostatic mixing valves (TMVs) have been used to blend hot and cold water to deliver safe, blended, hot water temperature for baths, basins and other points of use.

Thermostatic Shower Valves are now installed as standard fittings in most new homes. They offer householders improved comfort and inherent safety, irrespective of variations in water system pressures.

The introduction by NHS Estates Model Engineering Specification and the TMV3 Scheme (through BuildCert) ensures that TMVs installed in the high-risk sector deliver precise temperature control (preventing scalding) and are safer and easier to maintain.

For lower risk applications, such as in housing association installations, manufacturers introduced a new TMV2 Scheme, also administered by BuildCert. Both schemes guarantee that products are independently tested and certified to conform to a rigorous set of performance and endurance criteria.

For guidance on product suitability, see the BRE / DTI document IP14/03 'Preventing Hot Water Scaldings in Bathrooms'.

Applications Guide

• TMV 2 - Domestic users, housing associations, hotels.
• TMV 3 - High Risk environments, hospitals, nursing homes.

During May 2006, Scotland's building regulations legislation was amended. It required developers and contractors of all new homes to incorporate a thermostatic control to prevent scalding and provide safe hot bathing water (maximum temperature of 48oC).

The 'Hot Water Burns Like Fire' campaign seeks to deliver amendments to Building Regulations for England, Wales and Northern Ireland in order that children and the elderly (those most at risk) have equal protection to those in Scotland from scalding.

Shower control solutions

The UK has seen massive growth in the installation of thermostatic shower valves in new and existing properties.

Consumers have identified the benefits of peace of mind through improved safety and comfort and in part this is due to our traditional use of low pressure water storage system.

We can all remember the time before thermostatic showers, where having just got our manual mixing valve adjusted to a comfortable shower temperature ... little Johnny flushed the down stair loo.

Yes, we had to move fast in those days to stay safe.

But the use of 'domestic' thermostatic shower valves in commercial applications comes at a cost.

Designed to deliver high performance at low pressure in the domestic, it will in commercial applications - where the typical system pressure is 2.0 - 3.0 bar:

• Significantly increase water and energy costs.
• Increase the size and capacity of hot water generators and pipe work.
• Increase drainage sizes to take away this excessive water supply.

Table 1 Shower control solution - comparative water savings

Gives us an overview of the water savings available as compared with the traditional 'Classic' thermostatic shower valve at 2.5 bar.

• Classic' thermostatic shower valve without flow regulation.
• 'Classic' thermostatic shower valve with flow regulation at 10 Lpm.
• Time flow shower control with nominal time 30 secs and regulated flow at 8 Lpm.
• Thermostatic electronic shower control, combines full thermostatic performance with infrared on/off control for maximum water efficiency.

Basin control solutions

Increasingly, the cost of water supply and drainage will impact on the bottom line of business.

When we consider that 'Hot' water costs us between five and eight times the cost of cold water with energy, storage and treatment costs then the impact on margins of high water users is dramatic.

Motorway service areas, schools, leisure companies and retail sectors are seeing massive increases associated with water supply.

The traditional basin tap, designed for typical low-pressure applications, is a 'water waster' in today's modern commercial plumbing systems.

Table 2 Basin control solution - comparative water savings

Gives an overview of the water savings available when compared with the traditional 'Classic' basin tap at 2.5 bar.

• 'Classic' basin tap or mixer, traditional low pressure tap without flow regulation.
• Time flow basin tap or mixer, with flow regulation at 6 Lpm (adjustable) and automatic close after a nominal 15 secs run time.
• Electronic basin tap or mixer, with preset flow rate at 6 Lpm and automatic close on removal of hands.

For example, the Douglas Tempomatic and Tempomatic Mix range of electronic basin taps and mixers now incorporate an anti-legionella feature, which provides and automatic duty flush cycle of one minute, if the tap has not been used in the previous 24 hours.

Our website, www.douglascontrols.co.uk, enables effective comparison of water savings available from different control solutions.

Responsibility

In 1992, The Dublin Statement on Water and Sustainability was issued following an international conference on water and the environment.

Experts saw 'the emerging water resource condition as critical.'

They summarized: 'The problems highlighted are not speculative, nor are they likely to affect our planet only in the distant future: they are here and they affect humanity now.'

The European Water Charter reminds us of our responsibility:

"Water is a common heritage and its value must be acknowledged by all of us. Everyone must save it and use it carefully."