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Theme: plumbing and drainage

As increasing concern over water supplies makes the need for efficient use more pressing and technology develops in ever-more sophisticated ways, the provision of plumbing and drainage is becoming increasingly complex

Each year, the UK consumes 15 billion litres of water and discharges more than 10 million tonnes of wastewater. This is a big challenge, and an equally big industry has built up to meet it.

For architects, there are a number of factors that make their task more difficult.

Issues including the need for sustainable urban drainage systems (SUDS), dwindling water supplies, increasing pressure to make systems more efficient, asbestos, and new technology such as 'touch free' sanitary appliances, combine to make this a minefield for the specifier.

The movement towards SUDS is the result of the relatively recent realisation that for hundreds of years our rainwater management has been wrong. Piping water from roofs and paved areas directly to streams and rivers that in turn needed to be straightened and turned into virtual pipes, can no longer cope with the flow from today's urban areas.

Despite the fact that water tables are dropping alarmingly, flooding is increasing as the infrastructure is unable to cope with the volumes of water.

While much of the sustainability initiative focuses on methods of recharging the water table by allowing natural dissipation at source, others go further and recycle wastewater. This can be used for many nonpotable uses, such as flushing WCs, garden watering, in domestic applications or for cooling machinery for industrial use.

Under the sun Sustainability of a different sort is solar heating. There is a commonly held belief that the UK doesn't have enough sun to justify the cost but, according to the solar collector manufacturers, 'the amount of energy received by the sun in 30 minutes is the equivalent of the power used by the entire population of the earth in one year.' Set against this is the fact that some 70 per cent of the UK's annual radiation is received over the period April to September and 25 per cent in the months of June and July. This means that a solar system can really only be used to augment a conventional system and the 'pay back' calculations must be factored down accordingly.

Efficiency of collectors has been increasing steadily, and there are some very attractive Government subsidies on offer.

The DTI, under its Clear Skies initiative, is offering 50 per cent subsidies for solar heating on housing projects, significantly reducing the capital outlay. Not-for-profit organisations are eligible for grants under the Community Scheme, including community groups, environmental trusts, housing associations, local authorities, registered charities, schools, universities and hospitals.

Most solar collectors use similar technology, comprising an evacuated glass tube housing a linear flat-plate heat absorber. A special metallic fin is angled to catch maximum solar radiation and this is in turn attached to, or integrated with, tubes carrying the heat-transfer fluid. A control system ensures the fluid only circulates when the temperature in the absorber is higher than in the storage cylinder.

Drains on resources Government determination to reduce the amount of primary aggregate used in the construction industry has brought recent changes in regulations and taxation. In response, the Hepworth Super-Seal range of clay drainage pipes has been designed to be laid on a bed of some 20mm of single-sized granular material.

This is a significant reduction in material use compared with the full surround required by plastic pipes, for which need single-size 10mm pea shingle. In addition, more backfill can be returned to the trench, so reducing the quantity of material to be disposed of in landfill sites.

Smallest rooms Not content with minimising water usage, Green Building Store has developed Airflush which, as its name suggests, uses air instead of water to remove waste. Unlike waterbased rivals Airflush does not use expensive consumables. The manufacturer states that Airflush is suitable for public-sector and commercial applications, including offices, airports, schools, hospitals, and sports and leisure facilities such as hotels and bars.

Rainwater collection The whole issue of gutters becomes more important as climate change brings more cloudbursts. Many introductions focus on reducing installation costs with the development of smart fixing techniques. Marley, for example, has recently introduced its Deepflow Plus range of gutters, which provides a technical solution to jointing, reducing installation time. More radically, products such as Geberit's Pluvia syphonic rainwater drainage system allow greater design freedom, with reduced pipe dimensions and less site work.

Safe as houses Quality of life is also an important issue, and one that is being addressed in both amenity terms and to make facilities more widely available to everybody.

Hot water can be dangerous and causes 20 deaths and 570 serious scald injuries each year, mainly from baths. Most at risk are the young (under fives) and the old, who are particularly susceptible to scalds.

To address this issue, the government has ordered a review of Part G of the building regulations (hygiene) which could see all newly built or converted properties fitted with safety devices to control the water coming out of showers and hot water taps to baths and basins. Changes could come into force by 2006.

The Thermostatic Mixing Valve Manufacturers Association's (TMVA) main aim is the provision of safe hot water at point of use.

It has developed a certification scheme that includes two categories, TMV2 for domestic installations, and TMV3, which meets the more stringent NHS Estates DO8 for higher risk and healthcare installations.

Solutions can take the form of a thermostatic tap or a concealed valve. Manufacturer Intatec produces a range of products that also meet the requirements of BS EN1111 and BS EN1287.

Sounds good With increasing urban density and more people living in close proximity, noise pollution can be an issue. The revised Part E of the Building Regulations starts to address this.

Geberit is leading the way in this area, having recognised the increasing requirements for quiet plumbing. The company, which has its headquarters in Switzerland where noise restrictions are particularly stringent, has a mission to reduce sanitary noise in both water supply and waste systems. It has developed sophisticated technology to analyse unwelcome noise and virtually eliminate it. Its two-pronged attack deals with the issue through noise prevention and acoustic insulation. A low-noise concealed cistern and Unifil valve reduce inherent noise, and the company's Duofix/GIS dry wall insulation will absorb any airborne sounds. Finally, its Silent/db20 soundabsorbing drainage system should reduce noise from waste disposal.

Living well One of the UK's biggest growth areas arises from the public's demand for 'well being'.

As a result, fitness centres increasingly include the provision of spa facilities, long recognised as one the best forms of hydrotherapy. In the UK the Swimming Pool and Allied Trades Association (SPTATA) ensures that members' products and services meet strict guidelines. For those eager to reproduce some of the experience at home, Pharo by Hansgrohe is a range of showers and panels, ranging from standalone cubicles to fully integrated units including steam showers.

Warm thoughts The Swiss and Germans are clearly convinced of the benefits of underfloor heating (UFH) with 80 per cent and 35 per cent respectively of their new developments using the system.

Key advantages include:

better heat distribution, and higher efficiency;

higher proportion of radiant rather than convected heat, making buildings more comfortable and less draughty;

greater design freedom with the elimination of radiators;

lower water temperature and hence less fuel and reduced environmental damage.

So how does it work? Low-temperature water (approx 50° C) circulates through a series of continuous pipe loops laid under the floor, creating one radiant surface. Each room is one circuit and runs back to Manufacturers say that floor coverings are not restricted.

For an equivalent comfort level to that achieved with radiators, the room air temperature using UFH can be some 2° C lower, because the radiant heat warms the surfaces rather than the air. This in turn results in reduced energy usage.

For the more traditional, who still prefer convection, style is leading the way with a huge variety of exciting designs now available. Bisque produces one of the most comprehensive product lines, ranging from retro cast iron for re-creating authentic period interiors to imaginative contemporary designs.

Niche markets Not all developments need to be universally attractive. One development aimed at a very specific sector comes from Hepworth. Traditional U bend traps in washbasins have long been a problem for the hairdressing industry, with hair and chemical additives causing blockages and requiring regular maintenance. In response, Hepworth has developed a waste valve specifically for this application. Hepv0 makes use of a special membrane that allows water to flow through it unrestricted but closes to create an airtight seal when the flow ceases.

Providing goodquality mobile WCs for construction sites and events can be a challenge, and until now most have been unpleasant to say the least. To address this, Danfo has recently launched Pactosan, its 'ultra modern' site loo which even has solar cells to power lighting, running water and ventilation. The manufacturer claims this permits all the comforts normally associated with a permanent loo.

Pactosan can even be towed behind a car.

Hands free Commercial applications are increasingly turning towards 'hands free' technology for the operation of taps, urinal flushing, hand drying and even soap dispensers.

Most use infrared sensors, and benefits are two fold: increased hygiene and reduced water consumption. Geberit manufactures a comprehensive range of stylish washroom solutions.

Cleaning up Geberit's shower WCs are another import from Switzerland, where they are virtually standard. They are essentially a hybrid between a WC and a bidet, combining functions from both but adding warm-air drying and odour extraction. The units can be flooror wall-mounted, and offer adjustable air temperature, adjustable water spray intensity, optional remote control units, active carbon filters for odour extraction and a pressure switch to prevent unintended use. At present the units are mostly targeted at the health market in the UK, but the company is confident they will become popular in upmarket housing, particularly in developments that have a large number of buyers from Asia.

There are possible implications for drainage as a result of Building Regulations Approved document M (part M) which covers level access requirements. In response, Hepworth has developed a threshold drain that provides a flush drainage/waterproofing function to external doors. Available in a standard size of 1200mm, units can be linked to cater for wider openings and can be retrofitted to existing doors. Water is either discharged to the surrounding ground or piped away through 100mm clay or 40mm plastic pipes.

READER ENQUIRIES Bisque 1500 Corus Colorsteels 1501 Danfo 1502 FormPave 1503 Green Building Store 1504 Hansgrohe 1505 Hepworth 1506 Hydro 1507 IBP Conex 1508 Intatec 1509 Marley 1510 Pegler 1511 Redring 1512 Swimming Pool and Allied Trades Association 1513 Thermostatic Mixing Valve Manufacturers 1514 Association 1515 Uponor Housing Solutions 1516 WPL 1517 Yorkshire Fittings 1515 Enquire at www. ajplus. co. uk

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