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Advice Articles, FAQs

Water Treatment FAQ

October 22, 2024

Industrial and commercial humidification systems rely on mains water. While mains water is generally safe to drink and wash with, it’s not always suitable for every kind of humidification technology. Water treatment is required with some systems to promote healthier working environments and prolong the operational usage of humidification systems.  

Not all humidifiers require water treatment. In general, steam humidification of any kind produces sterile, clean steam to be distributed through the target environment.  

How does water treatment help humidification? 

Water treatment is used to soften water, filter out contaminates and prevent the spread of pathogens. Softened water helps resistive systems by limiting scale buildup, preventing breakdowns and reducing system strain. In adiabatic systems water treatment prevent nozzle blockage, prolongs a unit’s serviceable lifespan and reduces airborne pathogens.  

What water treatment is needed for an electrode humidifier? 

Answer: None, but may require regular cleaning or cylinder replacement 

Explanation: Electrode units work best in areas of hard water, as the system relies of the metallic ions and minerals in water to function. When treated the electric conductivity of the water is greatly decreased, reducing the functioning of the humidifier. Except in very particular circumstances, we would not recommend water treatment for this kind of unit. 

What water treatment is needed for a resistive humidifier? 

Answer: Reverse Osmosis or Water Softening 

Resistive humidifiers act a lot like kettles, relying on a submerged heating element to function. As water boils, it can leave behind a soft metal residue comprised of the minerals and impurities that were present in the water. Much like limescale, this residue can cling to the heating elements, reducing their effectiveness. Unlike electrode humidifiers, these units do not rely on water impurities to function. 

What water treatment is needed for an evaporative humidifier? 

Answer: Reverse Osmosis, Water Softening, UV light sterilisation 

This style of humidifier uses a water-bearing medium to introduce water directly into an air stream. It harnesses the natural process of evaporation, providing extra cooling to the target environment. The water used in this process is drawn directly from the mains supply without additional processing and can be improved to enhance health benefits and safety with treatment.   

What water treatment is needed for an ultrasonic humidifier? 

Answer: Reverse Osmosis, Water Softening, UV light sterilisation 

Similar to evaporative humidifiers, these models draw water directly from the mains supply. Using a vibrating plate, the liquid is aerolysed and introduced to the controlled environment through a dispersal unit. This supply can be improved through treatment. 

What water treatment is needed for a high-pressure humidifier? 

Answer: Reverse Osmosis, Water Softening, UV light sterilisation 

An adiabatic humidifier like their evaporative and ultrasonic counterparts, high pressure humidity systems introduce water vapour to an air stream or room by aerolysing liquid water through high pressure to create a dry mist. Because the water is drawn directly from the mains without further processing, we often recommend reverse osmosis for these units. This improves the air quality of the controlled environment and help prevent blockages in the nozzles due to scale buildup.    

What is reverse osmosis? 

Reverse Osmosis removes dissolved impurities

Reverse osmosis purifies water by passing it through a semi permeable membrane, purifying water down to a molecular level. The process is effective for removing salts, heavy metals, radiological and chemicals, micro-organisms and pharmaceuticals from a water supply. 

At Humidity solutions we often recommend the LK120 Reverse Osmosis Water Treatment Unit to help prevent scale build-up and help elongate the operational lifetime of units. 

What is water softening? 

Water softening removes calcium, magnesium and other metal ions from a water supply through ion exchange or chemical precipitation. This process helps lower scale build up, machinery wear and tear and fuel consumption. It is not considered as advance as reverse osmosis, but may be a good choice for lower scale applications where reverse osmosis isn’t available for possible. 

What is an UV sterilisation light? 

Any unit that draws from mains water, especially if they could be contaminated due to bad weather, outbreak for burst pipes, should be equipped with a UV sterilisation light as a safeguard against potential pathogens and legionella disease. Many models come with this feature as standard, but it is helpful to check. 

What does the law say about water purification and humidity? 

In the UK the HSE Approved Code of Practice L8 (2013) specifically refers to humidification systems as a risk in regards to Legionnaire’s disease. The disease causes a severe and potentially fatal illness which targets the respiratory system, making humidifiers, which may turn infected water into an aerosol, particularly dangerous. Legionnaire’s disease thrives in stagnant, nutrient-rich and mid-temperature water, which are common in irregularly maintained water systems such as water towers and tanks.  

This legislation is supported by the Health and Safety at Work Act (1974), the Management of Health and Safety at Work Regulations (1999) and the Control of Substances Hazardous to Health Regulations (2002) to create a framework for the prevention of Legionella and similar pathogenic diseases in water systems.  

Find more information about Legionella in water systems and the legal responsibilities of duty holders in the HSE’s Legionnaires’ disease: A brief guide for dutyholders’