The problems of scale

February 28, 2018

unit cooling sistem, close up

Facility managers (FM) in charge of maintaining chillers, boilers, heat exchangers, cooling towers, compressors or condensers know it’s not a matter of if they’ll have to deal with scale buildup, but when. Scale is the buildup of minerals (calcium, iron, magnesium, etc.) inside of your pipes and systems. Scale looks like white particles or pieces of paper. The problem is made worse with changes in water temperature, which is why boilers and cooling towers are often the most impacted systems. Left alone, scale will continue to build and will reduce your equipment’s lifespan, but even a small amount of scale can rob your equipment of efficiency.


Goodway Technologies, which offers descaling equipment and chemical solutions, has free online calculators to help FMs understand how much money they are losing to even small amounts of scale buildup.


Boiler scale, for example, has a low thermal conductivity, so when it forms on heat-transfer surfaces, it reduces heat transfer and causes inefficiency. Just a thin layer of scale can reduce efficiency by 10 percent or more. To help prevent scale buildup, it’s best to use chemical water treatment and makeup water pretreatment, but even then you will need to clean your boiler tubes regularly.


With chiller heat exchangers, a scale deposit of only .036 inches can increase energy costs over 30 percent. If you need to use a chemical descaler, most chiller manufacturers recommend consulting with a local water-treatment supplier to determine which chemical solution is best for you. A mechanical cleaning should always follow a chemical cleaning. Newer chillers feature automatic tube-brushing systems, which can be retrofitted onto existing chillers.


With cooling towers, FMs not only have to worry about scale, but also the buildup of the bacteria that causes Legionnaire’s Disease. Towers need to be inspected monthly, cleaned, and treated with a biodegradable descaler.


For more help with preventative maintenance or descaling your equipment, contact Vanguard Resources.