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Dealing with Limescale in Commercial Buildings

PHOTO CREDIT: Jan De Baat Doelman, Scalewatcher

Limescale is a hard, chalky substance that builds up in water systems and appliances due to the presence of calcium carbonate deposits in the water supply. This results in crystal formation that produces calcite coating surfaces and reducing functionality and energy efficiency. The scale also becomes breeding ground for bacteria. Within commercial buildings limescale results in build-up in the hot water systems, scale build-up in cooling towers and in washrooms and a shorter lifespan for water-fed equipment. A compounding issue caused by hard water is corrosion in iron pipework which initially starts with pitting and leads to total corrosion - necessitating pipelines to be replaced.

While many commercial buildings experience similar problems with limescale and corrosion some have their own specific problems:

Offices

The main areas affected by scale in offices are cooling towers, restrooms, canteens, hot water systems and kitchens.

Limescale affects cooling systems with health agencies drawing attention to the potential problems caused by scale and algae in cooling towers which impairs heat transfer, interferes with flow and cooling, and can be a breeding ground for legionella bacteria.

Scale also builds up in washrooms resulting in faucets becoming blocked and toilets looking unpleasant and become a breeding ground for germs. Shower heads require frequent descaling and basins require high-duty cleaning products.  Offices that have canteens or break areas, scale gradually builds-up and starts to effect water-fed appliances reducing their efficiency and necessitating early replacement.

Hotels

As well as the problems featured above, hotels also experience problems with swimming pools, water-fed equipment such as dish washers, steamers, bottle washers and in gardens.

Chlorine is necessary in swimming pools to deal with the bacteria that build up within the water and pool filtration system. A bacterium is introduced through a range of sources including from users of the pool which will thrive in the warm conditions. Water evaporation results in the total dissolved solids (TDS) levels increasing to levels far and above those of the incoming water and much of the calcium content ends up coating the surfaces of the pool and associated filtration systems. The body yeast which is essentially dead skin shed by pool users sticks to the calcium at the edges of the pool resulting in a very stubborn tidemark. This scale becomes both a source of nourishment and accommodation for the bacteria, which if left untreated, poses potential health problems to users of the pool.

Kitchens use water-fed equipment which gradually becomes coated with scale, and therefore require more power to heat in addition to reducing efficiency and necessitating early replacement.  Hotel with gardens using automated watering systems, sprinkler irrigation systems find that they block with limescale and in addition plant leaves develop white scale deposits.

Hospitals

In addition to bathrooms, restrooms, kitchens and cooling towers, hospitals also have problems with hard water in sterilizers. Water is the main constituent used to clean, rinse and the steam sterilization of stainless steel surgical instruments and laboratory autoclaves. Water from faucets contains a variety of dissolved minerals and salts. Dependent upon where you are and where your water originates (ground well, lake, river, etc.) the volume of these dissolved minerals can be very high.  Water develops higher levels of hardness the more minerals it contains. When hard water is becomes steam or is cooled to treat waste, it results in salt and mineral deposits being left behind. Over time these deposit build up like layers of paint within a steam generator, pipes, and valves. The consequential build-up decreases the efficiency and functionality of the steam generator in addition to clogging up pipes and valves. Hospitals have historically installed very long pipelines some of which are not used frequently and therefore allow bacteria to grow.

Electronic Water Conditioning

Electronic Water Treatment (EWT) requires no plumbing, chemicals or maintenance. The system utilizes a solenoid coil or coils that are wrapped around the pipework which requires treating. A frequency-changing signal generator supplies continuous current to the coils within a predetermined range. The pulsating-current creates an induced electric field, which focuses around the axis of the pipe. Consequently the charged particle or ion moving within the electric field is subjected to a ‘Lorentz force’ generated by the interaction between the charged particles and magnetic and electric fields.

The treatment effects the preliminary nucleation which in turn stops the crystals from "sticking" together on surfaces. Untreated water causes matted structures to build up that keep growing. However EWT creates idiomorphic, scattered crystals that no longer form matted structures. Unlike normal particles they are smaller and rounder which results in them having a larger volume in relation to the surface. As such this makes the particles sensitive to water currents so they can be easily flushed away in the pipeline. As no new surface of scale layers are formed, the force of the water flow will gradually remove existing scale. The technology’s ability to adjust power, frequency and coil configurations means that electronic water conditioning products can minimize equipment downtime and reduce the need for pipe replacement.

How Electronic Devices Operate

Recent scientific literature describes the macro effects as a consequence of fundamental interactions between applied fields and precipitating substances. The amount of energy introduced by a solenoid coil is very small – a Scalewatcher domestic unit uses less than a cordless telephone. In order to study the induced fields, it is necessary to use high precision scientific tools that do not affect the interactions such as an atomic force microscope (AFM), capable of examining growth patterns at the highest resolution on surfaces.

Hot water heaters, boilers, and plumbing equipment must be maintained to keep a commercial building running at peak performance and profitability. In hard water areas appliances will generally consume more energy if they become blocked by limescale, not only increasing costs but also resulting in the appliance being more prone to failure. Just a fraction of an inch of limescale in a hot water system or boiler will decrease heat transfer by 10%. This rises to a staggering 38% more energy with ¼ inch of scale – an amount that can easily form in 2 years. 

Installing electronic water conditioning equipment not only saves on energy, wasted water, the early renewal of capital equipment, maintenance and downtime but is also helps the environment.  To ensure that you select the correctly sized system for your building arrange for a site survey from a specialist electronic water conditioning specialist who will not only be able to advise you but also install the equipment.

Jan De Baat Doelman is president of Scalewatcher North America

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