ROUNDTABLE | PIPEWORK MATERIALS I would like to see the sharing of new technologies that will make the world a better place Caroline Ayres properties are added it would be interesting to see the price difference. But has the specification of plastic piping not been affected by the crusade against plastic pollution led by renowned broadcaster Sir David Attenborough? We havent found many people on the environmental or Attenborough side not specifying pipework because its plastic, its more to do with single-use plastics and packaging, said Caroline Ayres, director of the British Plastic Federation Pipes Group. In response to an increasing environmental concern about plastic, Ayres said that The European Plastics Pipes and Fittings Association (TEPPFA), has produced environmental product declarations for nearly every material and application based on cradle-to-grave scenarios, which are available to specifiers and consultants (see page 53). These declarations consider a wide range of aspects dictated by European standards from depletion of resources to carbon emissions to recycling to how much energy is used in manufacturing, said Ayres. This means that the Breeam projects can look at these declarations and make judgements. It isnt that plastics arent environmentally friendly, its more complex than that. Concrete, metals, cast iron all have issues with manufacturing and environmental impacts and they also need to be judged and assessed. Gaunt and Davis added that plastics are, increasingly, playing a key role in offsite prefabrication and kit technology given the benefits of quality control and pressure testing. Gaunt said that three out of 10 Cundall schemes have a level of prefabrication. Given these advantages, pod bathrooms are also growing in popularity. But, they still come with challenges. According to Davis, many pod manufacturers conceal pipework and components, which makes it very difficult for the installer. There is also the issue of compatibility different companies are involved, each specifying their own material and size of pipework. Gaunt said managing water temperatures for domestic water systems is also a challenge. To comply with Building Regulations, they need to be kept below 20C. This is difficult in high-end residential schemes that are fitted with luxury monsoon showers featuring significant flowrates. These properties are often empty for several months and, in these cases, water can sit in the pipework system for some time, leading to water temperatures sometimes peaking at 37C. Periods of these elevated temperatures means that bacteria can grow, such as legionella. When that water is discharged in a mist from showers or flushing toilets, the inhalation of that mist can have serious human-health implications. Pipe specification and sizing is an issue and larger pipe sizes can lead to stagnation of water, said Gaunt. As engineers we have to design to standards. Work is currently being undertaken by Heriot-Watt University and CIBSE called the Loading Units Normalisation Assessment (Luna) Programme, to develop more up-to-date pipe-sizing tools. We have the theoretical data but we need real-life water-flow measurements in residential buildings to help us understand water usage and how sites are working. In summing up, the roundtable members emphasised the importance of better education, training and the sharing of knowledge to improve competency when specifying the right materials and sizing of pipework. I would like to see the sharing of new technologies that will make the world a better place, said Ayres. Rainwater recycling, underfloor heating, district heating, theres an awful lot out there thats a bit niche. If it came into the mainstream that would be good. CJ Plastic, which is often cheaper, is embraced more readily by the younger generation Mark Davis 58 October 2019 www.cibsejournal.com CIBSE Oct19 pp54-56, 58 Roundtable.indd 58 20/09/2019 16:08