The risk of illness, such as legionella increases in summer, says Barry McGraw, the sales manager of Pipe Lagging, a leading Armacell Stockist pipe lagging supplier. Barry states “during the summer period, the water stagnates in the pipes, turning heating, ventilation, air conditioning, and plumbing systems into an ideal field of cultivation for bacteria, a very ubiquitous microorganism that lives free in the environment and is present in all aquatic habitats. Around 1,000 cases of legionellosis are declared in the UK each year. The bacterium, from these natural reservoirs, goes on to colonize the supply systems of cities, and through the water distribution network, it is consolidated into sanitary water systems, whether cold or hot and others that can generate aerosols, such as showers, evaporative condensers, and cooling towers, swimming pools or hot tubs (spas and hot tubs). Errors in the design and installation of sanitary systems can also lead to a dangerous increase in the bacteria in drinking water. Therefore, one of the most vital preventive measures is the correct insulation of hot and cold water pipes using suitable materials.”
95% of legionella cases are not detected
Legionella bacteria can penetrate the drinking water facilities of buildings through the main water supply network. There is a possibility that it will multiply in standing water at temperatures between 25 and 45oC. The bacteria becomes a hazard when inhaled in the form of small droplets (e.g., such as steam that appears when taking a shower). People with chronic conditions, those who are restricted to bed, or those with a vulnerable immune system are especially prone to Legionnaires’ disease, which can be fatal. Because symptoms are comparable to flu symptoms, the disease is often not diagnosed accurately.
A combination of steps to prevent microbial contamination
There are a number of operational, architectural and procedural steps to prevent the dangerous multiplication of legionella in your drinking water and, wherever possible, a mixture of these steps should be performed. Apart from making sure that water moves continuously within the pipes, it is also necessary to avoid unacceptable drops in temperature in hot water pipes, as well as temperature increases in cold water pipes. According to guides, cold drinking water pipes should not be placed next to heating ducts or hot water pipes, nor should they pass through hot areas, such as cabinets with heating systems to dry clothes. Cold water pipes should be protected against increased heat by leaving enough space or by proper insulation. Similar requirements are also valid to protect hot water pipes from heat loss.
Hot pipes should remain hot and cold pipes should remain cold
The minimum thickness of insulation substances for pipes and fittings must comply with regulations. In the face of an increased risk of legionella, pipes must be adequately insulated, for example in cases where hot and cold water pipes occupy the same duct or groove, or where water does not circulate regularly. In these cases, Armacell recommends using what is known as 100% insulation, i.e. an insulation thickness that corresponds approximately to the outer diameter of the tube. In hot drinking water pipes, this not only prevents legionella but also protects pipes from unnecessary heat loss.
Proper insulation material prevents condensation
Due to the risk of condensation, only closed cell insulation materials with high resistance to the diffusion of water vapour should be used in drinking water pipes. In practice, studies of damage have shown that open cell insulation materials (with or without barrier to steam) are not enough to stop moisture intrusion occurring from diffusion, so they cannot be viewed as protection effective against condensation. In these materials, the resistance to the distribution of water vapour is compressed in the barrier against steam. Even if the systems have been established with the highest care, they may not be completely waterproof and it is often futile to prevent water from penetrating. This means that there is a risk that air entering the insulation will include water vapour, quickly condensing and moistening the insulation material. As dampness in the material rises, thermal conductivity increases, insulation properties decline and energy losses will increase. In addition, corrosion may transpire with ensuing collateral damage.